auto-upgrade: add a test case with no permission to lock the repository

This show the current behavior when the repository is unlockable.

The current behavior is to abort, which is probably not great. Now that we have
a proper test, we can think about the behavior we want in a later changeset.

Differential Revision: https://phab.mercurial-scm.org/D12615

tests/test-upgrade-repo.t

@@ -1,2063 +1,2078
 #require no-reposimplestore
 
   $ cat >> $HGRCPATH << EOF
   > [extensions]
   > share =
   > [format]
   > # stabilize test accross variant
   > revlog-compression=zlib
   > [storage]
   > dirstate-v2.slow-path=allow
   > EOF
 
 store and revlogv1 are required in source
 
   $ hg --config format.usestore=false init no-store
   $ hg -R no-store debugupgraderepo
   abort: cannot upgrade repository; requirement missing: store
   [255]
 
   $ hg init no-revlogv1
   $ cat > no-revlogv1/.hg/requires << EOF
   > dotencode
   > fncache
   > generaldelta
   > store
   > EOF
 
   $ hg -R no-revlogv1 debugupgraderepo
   abort: cannot upgrade repository; missing a revlog version
   [255]
 
 Cannot upgrade shared repositories
 
   $ hg init share-parent
   $ hg -R share-parent debugbuilddag -n .+9
   $ hg -R share-parent up tip
   10 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg -q share share-parent share-child
 
   $ hg -R share-child debugupgraderepo --config format.sparse-revlog=no
   abort: cannot use these actions on a share repository: sparserevlog
   (upgrade the main repository directly)
   [255]
 
 Unless the action is compatible with share
 
   $ hg -R share-child debugupgraderepo --config format.use-dirstate-v2=yes --quiet
   requirements
      preserved: * (glob)
      added: dirstate-v2
   
   no revlogs to process
   
 
   $ hg -R share-child debugupgraderepo --config format.use-dirstate-v2=yes --quiet --run
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      added: dirstate-v2
   
   no revlogs to process
   
   $ hg debugformat -R share-child | grep dirstate-v2
   dirstate-v2:        yes
   $ hg debugformat -R share-parent | grep dirstate-v2
   dirstate-v2:         no
   $ hg status --all -R share-child
   C nf0
   C nf1
   C nf2
   C nf3
   C nf4
   C nf5
   C nf6
   C nf7
   C nf8
   C nf9
   $ hg log -l 3 -R share-child
   changeset:   9:0059eb38e4a4
   tag:         tip
   user:        debugbuilddag
   date:        Thu Jan 01 00:00:09 1970 +0000
   summary:     r9
   
   changeset:   8:4d5be70c8130
   user:        debugbuilddag
   date:        Thu Jan 01 00:00:08 1970 +0000
   summary:     r8
   
   changeset:   7:e60bfe72517e
   user:        debugbuilddag
   date:        Thu Jan 01 00:00:07 1970 +0000
   summary:     r7
   
   $ hg status --all -R share-parent
   C nf0
   C nf1
   C nf2
   C nf3
   C nf4
   C nf5
   C nf6
   C nf7
   C nf8
   C nf9
   $ hg log -l 3 -R share-parent
   changeset:   9:0059eb38e4a4
   tag:         tip
   user:        debugbuilddag
   date:        Thu Jan 01 00:00:09 1970 +0000
   summary:     r9
   
   changeset:   8:4d5be70c8130
   user:        debugbuilddag
   date:        Thu Jan 01 00:00:08 1970 +0000
   summary:     r8
   
   changeset:   7:e60bfe72517e
   user:        debugbuilddag
   date:        Thu Jan 01 00:00:07 1970 +0000
   summary:     r7
   
 
   $ hg -R share-child debugupgraderepo --config format.use-dirstate-v2=no --quiet --run
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      removed: dirstate-v2
   
   no revlogs to process
   
   $ hg debugformat -R share-child | grep dirstate-v2
   dirstate-v2:         no
   $ hg debugformat -R share-parent | grep dirstate-v2
   dirstate-v2:         no
   $ hg status --all -R share-child
   C nf0
   C nf1
   C nf2
   C nf3
   C nf4
   C nf5
   C nf6
   C nf7
   C nf8
   C nf9
   $ hg log -l 3 -R share-child
   changeset:   9:0059eb38e4a4
   tag:         tip
   user:        debugbuilddag
   date:        Thu Jan 01 00:00:09 1970 +0000
   summary:     r9
   
   changeset:   8:4d5be70c8130
   user:        debugbuilddag
   date:        Thu Jan 01 00:00:08 1970 +0000
   summary:     r8
   
   changeset:   7:e60bfe72517e
   user:        debugbuilddag
   date:        Thu Jan 01 00:00:07 1970 +0000
   summary:     r7
   
   $ hg status --all -R share-parent
   C nf0
   C nf1
   C nf2
   C nf3
   C nf4
   C nf5
   C nf6
   C nf7
   C nf8
   C nf9
   $ hg log -l 3 -R share-parent
   changeset:   9:0059eb38e4a4
   tag:         tip
   user:        debugbuilddag
   date:        Thu Jan 01 00:00:09 1970 +0000
   summary:     r9
   
   changeset:   8:4d5be70c8130
   user:        debugbuilddag
   date:        Thu Jan 01 00:00:08 1970 +0000
   summary:     r8
   
   changeset:   7:e60bfe72517e
   user:        debugbuilddag
   date:        Thu Jan 01 00:00:07 1970 +0000
   summary:     r7
   
 
 Do not yet support upgrading treemanifest repos
 
   $ hg --config experimental.treemanifest=true init treemanifest
   $ hg -R treemanifest debugupgraderepo
   abort: cannot upgrade repository; unsupported source requirement: treemanifest
   [255]
 
 Cannot add treemanifest requirement during upgrade
 
   $ hg init disallowaddedreq
   $ hg -R disallowaddedreq --config experimental.treemanifest=true debugupgraderepo
   abort: cannot upgrade repository; do not support adding requirement: treemanifest
   [255]
 
 An upgrade of a repository created with recommended settings only suggests optimizations
 
   $ hg init empty
   $ cd empty
   $ hg debugformat
   format-variant     repo
   fncache:            yes
   dirstate-v2:         no
   tracked-hint:        no
   dotencode:          yes
   generaldelta:       yes
   share-safe:         yes
   sparserevlog:       yes
   persistent-nodemap:  no (no-rust !)
   persistent-nodemap: yes (rust !)
   copies-sdc:          no
   revlog-v2:           no
   changelog-v2:        no
   plain-cl-delta:     yes
   compression:        zlib
   compression-level:  default
   $ hg debugformat --verbose
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   tracked-hint:        no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:         yes    yes     yes
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zlib   zlib    zstd (zstd !)
   compression-level:  default default default
   $ hg debugformat --verbose --config format.usefncache=no
   format-variant     repo config default
   fncache:            yes     no     yes
   dirstate-v2:         no     no      no
   tracked-hint:        no     no      no
   dotencode:          yes     no     yes
   generaldelta:       yes    yes     yes
   share-safe:         yes    yes     yes
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zlib   zlib    zstd (zstd !)
   compression-level:  default default default
   $ hg debugformat --verbose --config format.usefncache=no --color=debug
   format-variant     repo config default
   [formatvariant.name.mismatchconfig|fncache:           ][formatvariant.repo.mismatchconfig| yes][formatvariant.config.special|     no][formatvariant.default|     yes]
   [formatvariant.name.uptodate|dirstate-v2:       ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|tracked-hint:      ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.mismatchconfig|dotencode:         ][formatvariant.repo.mismatchconfig| yes][formatvariant.config.special|     no][formatvariant.default|     yes]
   [formatvariant.name.uptodate|generaldelta:      ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.uptodate|share-safe:        ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.uptodate|sparserevlog:      ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.uptodate|persistent-nodemap:][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no] (no-rust !)
   [formatvariant.name.mismatchdefault|persistent-nodemap:][formatvariant.repo.mismatchdefault| yes][formatvariant.config.special|    yes][formatvariant.default|      no] (rust !)
   [formatvariant.name.uptodate|copies-sdc:        ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|revlog-v2:         ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|changelog-v2:      ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|plain-cl-delta:    ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.uptodate|compression:       ][formatvariant.repo.uptodate| zlib][formatvariant.config.default|   zlib][formatvariant.default|    zlib] (no-zstd !)
   [formatvariant.name.mismatchdefault|compression:       ][formatvariant.repo.mismatchdefault| zlib][formatvariant.config.special|   zlib][formatvariant.default|    zstd] (zstd !)
   [formatvariant.name.uptodate|compression-level: ][formatvariant.repo.uptodate| default][formatvariant.config.default| default][formatvariant.default| default]
   $ hg debugformat -Tjson
   [
    {
     "config": true,
     "default": true,
     "name": "fncache",
     "repo": true
    },
    {
     "config": false,
     "default": false,
     "name": "dirstate-v2",
     "repo": false
    },
    {
     "config": false,
     "default": false,
     "name": "tracked-hint",
     "repo": false
    },
    {
     "config": true,
     "default": true,
     "name": "dotencode",
     "repo": true
    },
    {
     "config": true,
     "default": true,
     "name": "generaldelta",
     "repo": true
    },
    {
     "config": true,
     "default": true,
     "name": "share-safe",
     "repo": true
    },
    {
     "config": true,
     "default": true,
     "name": "sparserevlog",
     "repo": true
    },
    {
     "config": false, (no-rust !)
     "config": true, (rust !)
     "default": false,
     "name": "persistent-nodemap",
     "repo": false (no-rust !)
     "repo": true (rust !)
    },
    {
     "config": false,
     "default": false,
     "name": "copies-sdc",
     "repo": false
    },
    {
     "config": false,
     "default": false,
     "name": "revlog-v2",
     "repo": false
    },
    {
     "config": false,
     "default": false,
     "name": "changelog-v2",
     "repo": false
    },
    {
     "config": true,
     "default": true,
     "name": "plain-cl-delta",
     "repo": true
    },
    {
     "config": "zlib",
     "default": "zlib", (no-zstd !)
     "default": "zstd", (zstd !)
     "name": "compression",
     "repo": "zlib"
    },
    {
     "config": "default",
     "default": "default",
     "name": "compression-level",
     "repo": "default"
    }
   ]
   $ hg debugupgraderepo
   (no format upgrades found in existing repository)
   performing an upgrade with "--run" will make the following changes:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
   
   no revlogs to process
   
   additional optimizations are available by specifying "--optimize <name>":
   
   re-delta-parent
      deltas within internal storage will be recalculated to choose an optimal base revision where this was not already done; the size of the repository may shrink and various operations may become faster; the first time this optimization is performed could slow down upgrade execution considerably; subsequent invocations should not run noticeably slower
   
   re-delta-multibase
      deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
   
   re-delta-all
      deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
   
   re-delta-fulladd
      every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
   
 
   $ hg debugupgraderepo --quiet
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
   
   no revlogs to process
   
 
 --optimize can be used to add optimizations
 
   $ hg debugupgrade --optimize 're-delta-parent'
   (no format upgrades found in existing repository)
   performing an upgrade with "--run" will make the following changes:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   additional optimizations are available by specifying "--optimize <name>":
   
   re-delta-multibase
      deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
   
   re-delta-all
      deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
   
   re-delta-fulladd
      every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
   
 
 modern form of the option
 
   $ hg debugupgrade --optimize re-delta-parent
   (no format upgrades found in existing repository)
   performing an upgrade with "--run" will make the following changes:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   additional optimizations are available by specifying "--optimize <name>":
   
   re-delta-multibase
      deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
   
   re-delta-all
      deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
   
   re-delta-fulladd
      every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
   
   $ hg debugupgrade --optimize re-delta-parent --quiet
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
 
 unknown optimization:
 
   $ hg debugupgrade --optimize foobar
   abort: unknown optimization action requested: foobar
   (run without arguments to see valid optimizations)
   [255]
 
 Various sub-optimal detections work
 
   $ cat > .hg/requires << EOF
   > revlogv1
   > store
   > EOF
 
   $ hg debugformat
   format-variant     repo
   fncache:             no
   dirstate-v2:         no
   tracked-hint:        no
   dotencode:           no
   generaldelta:        no
   share-safe:          no
   sparserevlog:        no
   persistent-nodemap:  no
   copies-sdc:          no
   revlog-v2:           no
   changelog-v2:        no
   plain-cl-delta:     yes
   compression:        zlib
   compression-level:  default
   $ hg debugformat --verbose
   format-variant     repo config default
   fncache:             no    yes     yes
   dirstate-v2:         no     no      no
   tracked-hint:        no     no      no
   dotencode:           no    yes     yes
   generaldelta:        no    yes     yes
   share-safe:          no    yes     yes
   sparserevlog:        no    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap:  no    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zlib   zlib    zstd (zstd !)
   compression-level:  default default default
   $ hg debugformat --verbose --config format.usegeneraldelta=no
   format-variant     repo config default
   fncache:             no    yes     yes
   dirstate-v2:         no     no      no
   tracked-hint:        no     no      no
   dotencode:           no    yes     yes
   generaldelta:        no     no     yes
   share-safe:          no    yes     yes
   sparserevlog:        no     no     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap:  no    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zlib   zlib    zstd (zstd !)
   compression-level:  default default default
   $ hg debugformat --verbose --config format.usegeneraldelta=no --color=debug
   format-variant     repo config default
   [formatvariant.name.mismatchconfig|fncache:           ][formatvariant.repo.mismatchconfig|  no][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.uptodate|dirstate-v2:       ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|tracked-hint:      ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.mismatchconfig|dotencode:         ][formatvariant.repo.mismatchconfig|  no][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.mismatchdefault|generaldelta:      ][formatvariant.repo.mismatchdefault|  no][formatvariant.config.special|     no][formatvariant.default|     yes]
   [formatvariant.name.mismatchconfig|share-safe:        ][formatvariant.repo.mismatchconfig|  no][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.mismatchdefault|sparserevlog:      ][formatvariant.repo.mismatchdefault|  no][formatvariant.config.special|     no][formatvariant.default|     yes]
   [formatvariant.name.uptodate|persistent-nodemap:][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no] (no-rust !)
   [formatvariant.name.mismatchconfig|persistent-nodemap:][formatvariant.repo.mismatchconfig|  no][formatvariant.config.special|    yes][formatvariant.default|      no] (rust !)
   [formatvariant.name.uptodate|copies-sdc:        ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|revlog-v2:         ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|changelog-v2:      ][formatvariant.repo.uptodate|  no][formatvariant.config.default|     no][formatvariant.default|      no]
   [formatvariant.name.uptodate|plain-cl-delta:    ][formatvariant.repo.uptodate| yes][formatvariant.config.default|    yes][formatvariant.default|     yes]
   [formatvariant.name.uptodate|compression:       ][formatvariant.repo.uptodate| zlib][formatvariant.config.default|   zlib][formatvariant.default|    zlib] (no-zstd !)
   [formatvariant.name.mismatchdefault|compression:       ][formatvariant.repo.mismatchdefault| zlib][formatvariant.config.special|   zlib][formatvariant.default|    zstd] (zstd !)
   [formatvariant.name.uptodate|compression-level: ][formatvariant.repo.uptodate| default][formatvariant.config.default| default][formatvariant.default| default]
   $ hg debugupgraderepo
   note:    selecting all-filelogs for processing to change: dotencode
   note:    selecting all-manifestlogs for processing to change: dotencode
   note:    selecting changelog for processing to change: dotencode
   
   repository lacks features recommended by current config options:
   
   fncache
      long and reserved filenames may not work correctly; repository performance is sub-optimal
   
   dotencode
      storage of filenames beginning with a period or space may not work correctly
   
   generaldelta
      deltas within internal storage are unable to choose optimal revisions; repository is larger and slower than it could be; interaction with other repositories may require extra network and CPU resources, making "hg push" and "hg pull" slower
   
   share-safe
      old shared repositories do not share source repository requirements and config. This leads to various problems when the source repository format is upgraded or some new extensions are enabled.
   
   sparserevlog
      in order to limit disk reading and memory usage on older version, the span of a delta chain from its root to its end is limited, whatever the relevant data in this span. This can severly limit Mercurial ability to build good chain of delta resulting is much more storage space being taken and limit reusability of on disk delta during exchange.
   
   persistent-nodemap (rust !)
      persist the node -> rev mapping on disk to speedup lookup (rust !)
    (rust !)
   
   performing an upgrade with "--run" will make the following changes:
   
   requirements
      preserved: revlogv1, store
      added: dotencode, fncache, generaldelta, share-safe, sparserevlog (no-rust !)
      added: dotencode, fncache, generaldelta, persistent-nodemap, share-safe, sparserevlog (rust !)
   
   fncache
      repository will be more resilient to storing certain paths and performance of certain operations should be improved
   
   dotencode
      repository will be better able to store files beginning with a space or period
   
   generaldelta
      repository storage will be able to create optimal deltas; new repository data will be smaller and read times should decrease; interacting with other repositories using this storage model should require less network and CPU resources, making "hg push" and "hg pull" faster
   
   share-safe
      Upgrades a repository to share-safe format so that future shares of this repository share its requirements and configs.
   
   sparserevlog
      Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
   
   persistent-nodemap (rust !)
      Speedup revision lookup by node id. (rust !)
    (rust !)
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   additional optimizations are available by specifying "--optimize <name>":
   
   re-delta-parent
      deltas within internal storage will be recalculated to choose an optimal base revision where this was not already done; the size of the repository may shrink and various operations may become faster; the first time this optimization is performed could slow down upgrade execution considerably; subsequent invocations should not run noticeably slower
   
   re-delta-multibase
      deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
   
   re-delta-all
      deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
   
   re-delta-fulladd
      every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
   
   $ hg debugupgraderepo --quiet
   requirements
      preserved: revlogv1, store
      added: dotencode, fncache, generaldelta, share-safe, sparserevlog (no-rust !)
      added: dotencode, fncache, generaldelta, persistent-nodemap, share-safe, sparserevlog (rust !)
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
 
   $ hg --config format.dotencode=false debugupgraderepo
   note:    selecting all-filelogs for processing to change: fncache
   note:    selecting all-manifestlogs for processing to change: fncache
   note:    selecting changelog for processing to change: fncache
   
   repository lacks features recommended by current config options:
   
   fncache
      long and reserved filenames may not work correctly; repository performance is sub-optimal
   
   generaldelta
      deltas within internal storage are unable to choose optimal revisions; repository is larger and slower than it could be; interaction with other repositories may require extra network and CPU resources, making "hg push" and "hg pull" slower
   
   share-safe
      old shared repositories do not share source repository requirements and config. This leads to various problems when the source repository format is upgraded or some new extensions are enabled.
   
   sparserevlog
      in order to limit disk reading and memory usage on older version, the span of a delta chain from its root to its end is limited, whatever the relevant data in this span. This can severly limit Mercurial ability to build good chain of delta resulting is much more storage space being taken and limit reusability of on disk delta during exchange.
   
   persistent-nodemap (rust !)
      persist the node -> rev mapping on disk to speedup lookup (rust !)
    (rust !)
   repository lacks features used by the default config options:
   
   dotencode
      storage of filenames beginning with a period or space may not work correctly
   
   
   performing an upgrade with "--run" will make the following changes:
   
   requirements
      preserved: revlogv1, store
      added: fncache, generaldelta, share-safe, sparserevlog (no-rust !)
      added: fncache, generaldelta, persistent-nodemap, share-safe, sparserevlog (rust !)
   
   fncache
      repository will be more resilient to storing certain paths and performance of certain operations should be improved
   
   generaldelta
      repository storage will be able to create optimal deltas; new repository data will be smaller and read times should decrease; interacting with other repositories using this storage model should require less network and CPU resources, making "hg push" and "hg pull" faster
   
   share-safe
      Upgrades a repository to share-safe format so that future shares of this repository share its requirements and configs.
   
   sparserevlog
      Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
   
   persistent-nodemap (rust !)
      Speedup revision lookup by node id. (rust !)
    (rust !)
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   additional optimizations are available by specifying "--optimize <name>":
   
   re-delta-parent
      deltas within internal storage will be recalculated to choose an optimal base revision where this was not already done; the size of the repository may shrink and various operations may become faster; the first time this optimization is performed could slow down upgrade execution considerably; subsequent invocations should not run noticeably slower
   
   re-delta-multibase
      deltas within internal storage will be recalculated against multiple base revision and the smallest difference will be used; the size of the repository may shrink significantly when there are many merges; this optimization will slow down execution in proportion to the number of merges in the repository and the amount of files in the repository; this slow down should not be significant unless there are tens of thousands of files and thousands of merges
   
   re-delta-all
      deltas within internal storage will always be recalculated without reusing prior deltas; this will likely make execution run several times slower; this optimization is typically not needed
   
   re-delta-fulladd
      every revision will be re-added as if it was new content. It will go through the full storage mechanism giving extensions a chance to process it (eg. lfs). This is similar to "re-delta-all" but even slower since more logic is involved.
   
 
   $ cd ..
 
 Upgrading a repository that is already modern essentially no-ops
 
   $ hg init modern
   $ hg -R modern debugupgraderepo --run
   nothing to do
 
 Upgrading a repository to generaldelta works
 
   $ hg --config format.usegeneraldelta=false init upgradegd
   $ cd upgradegd
   $ touch f0
   $ hg -q commit -A -m initial
   $ mkdir FooBarDirectory.d
   $ touch FooBarDirectory.d/f1
   $ hg -q commit -A -m 'add f1'
   $ hg -q up -r 0
   >>> import random
   >>> random.seed(0) # have a reproducible content
   >>> with open("f2", "wb") as f:
   ...     for i in range(100000):
   ...         f.write(b"%d\n" % random.randint(1000000000, 9999999999)) and None
   $ hg -q commit -A -m 'add f2'
 
 make sure we have a .d file
 
   $ ls -d .hg/store/data/*
   .hg/store/data/_foo_bar_directory.d.hg
   .hg/store/data/f0.i
   .hg/store/data/f2.d
   .hg/store/data/f2.i
 
   $ hg debugupgraderepo --run --config format.sparse-revlog=false
   note:    selecting all-filelogs for processing to change: generaldelta
   note:    selecting all-manifestlogs for processing to change: generaldelta
   note:    selecting changelog for processing to change: generaldelta
   
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, revlogv1, share-safe, store (no-rust !)
      preserved: dotencode, fncache, persistent-nodemap, revlogv1, share-safe, store (rust !)
      added: generaldelta
   
   generaldelta
      repository storage will be able to create optimal deltas; new repository data will be smaller and read times should decrease; interacting with other repositories using this storage model should require less network and CPU resources, making "hg push" and "hg pull" faster
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (384 bytes in store; 238 bytes tracked data)
   finished migrating 3 manifest revisions across 1 manifests; change in size: -17 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: -17 bytes
   copying phaseroots
   copying requires
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replaced files will be backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   copy of old repository backed up at $TESTTMP/upgradegd/.hg/upgradebackup.* (glob)
   the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified
 
 Original requirements backed up
 
   $ cat .hg/upgradebackup.*/requires
   share-safe
   $ cat .hg/upgradebackup.*/store/requires
   dotencode
   fncache
   persistent-nodemap (rust !)
   revlogv1
   store
   upgradeinprogress
 
 generaldelta added to original requirements files
 
   $ hg debugrequires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlogv1
   share-safe
   store
 
 store directory has files we expect
 
   $ ls .hg/store
   00changelog.i
   00manifest.i
   data
   fncache
   phaseroots
   requires
   undo
   undo.backupfiles
   undo.phaseroots
 
 manifest should be generaldelta
 
   $ hg debugrevlog -m | grep flags
   flags  : inline, generaldelta
 
 verify should be happy
 
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
 old store should be backed up
 
   $ ls -d .hg/upgradebackup.*/
   .hg/upgradebackup.*/ (glob)
   $ ls .hg/upgradebackup.*/store
   00changelog.i
   00manifest.i
   data
   fncache
   phaseroots
   requires
   undo
   undo.backup.fncache
   undo.backupfiles
   undo.phaseroots
 
 unless --no-backup is passed
 
   $ rm -rf .hg/upgradebackup.*/
   $ hg debugupgraderepo --run --no-backup
   note:    selecting all-filelogs for processing to change: sparserevlog
   note:    selecting all-manifestlogs for processing to change: sparserevlog
   note:    selecting changelog for processing to change: sparserevlog
   
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, store (rust !)
      added: sparserevlog
   
   sparserevlog
      Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   copying requires
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for * (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   $ ls -1 .hg/ | grep upgradebackup
   [1]
 
 We can restrict optimization to some revlog:
 
   $ hg debugupgrade --optimize re-delta-parent --run --manifest --no-backup --debug --traceback
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   blindly copying data/FooBarDirectory.d/f1.i containing 1 revisions
   blindly copying data/f0.i containing 1 revisions
   blindly copying data/f2.i containing 1 revisions
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   cloning 3 revisions from 00manifest.i
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   blindly copying 00changelog.i containing 3 revisions
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   copying requires
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
 
 Check that the repo still works fine
 
   $ hg log -G --stat
   @  changeset:   2:fca376863211 (py3 !)
   |  tag:         tip
   |  parent:      0:ba592bf28da2
   |  user:        test
   |  date:        Thu Jan 01 00:00:00 1970 +0000
   |  summary:     add f2
   |
   |   f2 |  100000 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
   |   1 files changed, 100000 insertions(+), 0 deletions(-)
   |
   | o  changeset:   1:2029ce2354e2
   |/   user:        test
   |    date:        Thu Jan 01 00:00:00 1970 +0000
   |    summary:     add f1
   |
   |
   o  changeset:   0:ba592bf28da2
      user:        test
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     initial
   
   
 
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
 Check we can select negatively
 
   $ hg debugupgrade --optimize re-delta-parent --run --no-manifest --no-backup --debug --traceback
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - all-filelogs
     - changelog
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   cloning 1 revisions from data/FooBarDirectory.d/f1.i
   cloning 1 revisions from data/f0.i
   cloning 1 revisions from data/f2.i
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   blindly copying 00manifest.i containing 3 revisions
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   cloning 3 revisions from 00changelog.i
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   copying requires
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
 Check that we can select changelog only
 
   $ hg debugupgrade --optimize re-delta-parent --run --changelog --no-backup --debug --traceback
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - changelog
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   blindly copying data/FooBarDirectory.d/f1.i containing 1 revisions
   blindly copying data/f0.i containing 1 revisions
   blindly copying data/f2.i containing 1 revisions
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   blindly copying 00manifest.i containing 3 revisions
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   cloning 3 revisions from 00changelog.i
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   copying requires
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
 Check that we can select filelog only
 
   $ hg debugupgrade --optimize re-delta-parent --run --no-changelog --no-manifest --no-backup --debug --traceback
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - all-filelogs
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   cloning 1 revisions from data/FooBarDirectory.d/f1.i
   cloning 1 revisions from data/f0.i
   cloning 1 revisions from data/f2.i
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   blindly copying 00manifest.i containing 3 revisions
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   blindly copying 00changelog.i containing 3 revisions
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   copying requires
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
 
 Check you can't skip revlog clone during important format downgrade
 
   $ echo "[format]" > .hg/hgrc
   $ echo "sparse-revlog=no" >> .hg/hgrc
   $ hg debugupgrade --optimize re-delta-parent --no-manifest --no-backup --quiet
   warning: ignoring  --no-manifest, as upgrade is changing: sparserevlog
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, store (rust !)
      removed: sparserevlog
   
   optimisations: re-delta-parent
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugupgrade --optimize re-delta-parent --run --manifest --no-backup --debug --traceback
   note:    selecting all-filelogs for processing to change: sparserevlog
   note:    selecting changelog for processing to change: sparserevlog
   
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, store (rust !)
      removed: sparserevlog
   
   optimisations: re-delta-parent
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   cloning 1 revisions from data/FooBarDirectory.d/f1.i
   cloning 1 revisions from data/f0.i
   cloning 1 revisions from data/f2.i
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   cloning 3 revisions from 00manifest.i
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   cloning 3 revisions from 00changelog.i
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   copying requires
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
 Check you can't skip revlog clone during important format upgrade
 
   $ echo "sparse-revlog=yes" >> .hg/hgrc
   $ hg debugupgrade --optimize re-delta-parent --run --manifest --no-backup --debug --traceback
   note:    selecting all-filelogs for processing to change: sparserevlog
   note:    selecting changelog for processing to change: sparserevlog
   
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, store (rust !)
      added: sparserevlog
   
   optimisations: re-delta-parent
   
   sparserevlog
      Revlog supports delta chain with more unused data between payload. These gaps will be skipped at read time. This allows for better delta chains, making a better compression and faster exchange with server.
   
   re-delta-parent
      deltas within internal storage will choose a new base revision if needed
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 519 KB in store; 1.05 MB tracked data
   migrating 3 filelogs containing 3 revisions (518 KB in store; 1.05 MB tracked data)
   cloning 1 revisions from data/FooBarDirectory.d/f1.i
   cloning 1 revisions from data/f0.i
   cloning 1 revisions from data/f2.i
   finished migrating 3 filelog revisions across 3 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 3 revisions (367 bytes in store; 238 bytes tracked data)
   cloning 3 revisions from 00manifest.i
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (394 bytes in store; 199 bytes tracked data)
   cloning 3 revisions from 00changelog.i
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: 0 bytes
   copying phaseroots
   copying requires
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/upgradegd/.hg/upgrade.* (glob)
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 3 changesets with 3 changes to 3 files
 
   $ cd ..
 
 store files with special filenames aren't encoded during copy
 
   $ hg init store-filenames
   $ cd store-filenames
   $ touch foo
   $ hg -q commit -A -m initial
   $ touch .hg/store/.XX_special_filename
 
   $ hg debugupgraderepo --run
   nothing to do
   $ hg debugupgraderepo --run --optimize 're-delta-fulladd'
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
   
   optimisations: re-delta-fulladd
   
   re-delta-fulladd
      each revision will be added as new content to the internal storage; this will likely drastically slow down execution time, but some extensions might need it
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/store-filenames/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 3 total revisions (1 in filelogs, 1 in manifests, 1 in changelog)
   migrating 301 bytes in store; 107 bytes tracked data
   migrating 1 filelogs containing 1 revisions (64 bytes in store; 0 bytes tracked data)
   finished migrating 1 filelog revisions across 1 filelogs; change in size: 0 bytes
   migrating 1 manifests containing 1 revisions (110 bytes in store; 45 bytes tracked data)
   finished migrating 1 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 1 revisions (127 bytes in store; 62 bytes tracked data)
   finished migrating 1 changelog revisions; change in size: 0 bytes
   finished migrating 3 total revisions; total change in store size: 0 bytes
   copying .XX_special_filename
   copying phaseroots
   copying requires
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replaced files will be backed up at $TESTTMP/store-filenames/.hg/upgradebackup.* (glob)
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/store-filenames/.hg/upgrade.* (glob)
   copy of old repository backed up at $TESTTMP/store-filenames/.hg/upgradebackup.* (glob)
   the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified
 
 fncache is valid after upgrade
 
   $ hg debugrebuildfncache
   fncache already up to date
 
   $ cd ..
 
 Check upgrading a large file repository
 ---------------------------------------
 
   $ hg init largefilesrepo
   $ cat << EOF >> largefilesrepo/.hg/hgrc
   > [extensions]
   > largefiles =
   > EOF
 
   $ cd largefilesrepo
   $ touch foo
   $ hg add --large foo
   $ hg -q commit -m initial
   $ hg debugrequires
   dotencode
   fncache
   generaldelta
   largefiles
   persistent-nodemap (rust !)
   revlogv1
   share-safe
   sparserevlog
   store
 
   $ hg debugupgraderepo --run
   nothing to do
   $ hg debugrequires
   dotencode
   fncache
   generaldelta
   largefiles
   persistent-nodemap (rust !)
   revlogv1
   share-safe
   sparserevlog
   store
 
   $ cat << EOF >> .hg/hgrc
   > [extensions]
   > lfs =
   > [lfs]
   > threshold = 10
   > EOF
   $ echo '123456789012345' > lfs.bin
   $ hg ci -Am 'lfs.bin'
   adding lfs.bin
   $ hg debugrequires | grep lfs
   lfs
   $ find .hg/store/lfs -type f
   .hg/store/lfs/objects/d0/beab232adff5ba365880366ad30b1edb85c4c5372442b5d2fe27adc96d653f
 
   $ hg debugupgraderepo --run
   nothing to do
 
   $ hg debugrequires | grep lfs
   lfs
   $ find .hg/store/lfs -type f
   .hg/store/lfs/objects/d0/beab232adff5ba365880366ad30b1edb85c4c5372442b5d2fe27adc96d653f
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checked 2 changesets with 2 changes to 2 files
   $ hg debugdata lfs.bin 0
   version https://git-lfs.github.com/spec/v1
   oid sha256:d0beab232adff5ba365880366ad30b1edb85c4c5372442b5d2fe27adc96d653f
   size 16
   x-is-binary 0
 
   $ cd ..
 
 repository config is taken in account
 -------------------------------------
 
   $ cat << EOF >> $HGRCPATH
   > [format]
   > maxchainlen = 1
   > EOF
 
   $ hg init localconfig
   $ cd localconfig
   $ cat << EOF > file
   > some content
   > with some length
   > to make sure we get a delta
   > after changes
   > very long
   > very long
   > very long
   > very long
   > very long
   > very long
   > very long
   > very long
   > very long
   > very long
   > very long
   > EOF
   $ hg -q commit -A -m A
   $ echo "new line" >> file
   $ hg -q commit -m B
   $ echo "new line" >> file
   $ hg -q commit -m C
 
   $ cat << EOF >> .hg/hgrc
   > [format]
   > maxchainlen = 9001
   > EOF
   $ hg config format
   format.revlog-compression=$BUNDLE2_COMPRESSIONS$
   format.maxchainlen=9001
   $ hg debugdeltachain file
       rev  chain# chainlen     prev   delta       size    rawsize  chainsize     ratio   lindist extradist extraratio   readsize largestblk rddensity srchunks
         0       1        1       -1    base         77        182         77   0.42308        77         0    0.00000         77         77   1.00000        1
         1       1        2        0      p1         21        191         98   0.51309        98         0    0.00000         98         98   1.00000        1
         2       1        2        0   other         30        200        107   0.53500       128        21    0.19626        128        128   0.83594        1
 
   $ hg debugupgraderepo --run --optimize 're-delta-all'
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
   
   optimisations: re-delta-all
   
   re-delta-all
      deltas within internal storage will be fully recomputed; this will likely drastically slow down execution time
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/localconfig/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   migrating 9 total revisions (3 in filelogs, 3 in manifests, 3 in changelog)
   migrating 1019 bytes in store; 882 bytes tracked data
   migrating 1 filelogs containing 3 revisions (320 bytes in store; 573 bytes tracked data)
   finished migrating 3 filelog revisions across 1 filelogs; change in size: -9 bytes
   migrating 1 manifests containing 3 revisions (333 bytes in store; 138 bytes tracked data)
   finished migrating 3 manifest revisions across 1 manifests; change in size: 0 bytes
   migrating changelog containing 3 revisions (366 bytes in store; 171 bytes tracked data)
   finished migrating 3 changelog revisions; change in size: 0 bytes
   finished migrating 9 total revisions; total change in store size: -9 bytes
   copying phaseroots
   copying requires
   data fully upgraded in a temporary repository
   marking source repository as being upgraded; clients will be unable to read from repository
   starting in-place swap of repository data
   replaced files will be backed up at $TESTTMP/localconfig/.hg/upgradebackup.* (glob)
   replacing store...
   store replacement complete; repository was inconsistent for *s (glob)
   finalizing requirements file and making repository readable again
   removing temporary repository $TESTTMP/localconfig/.hg/upgrade.* (glob)
   copy of old repository backed up at $TESTTMP/localconfig/.hg/upgradebackup.* (glob)
   the old repository will not be deleted; remove it to free up disk space once the upgraded repository is verified
   $ hg debugdeltachain file
       rev  chain# chainlen     prev   delta       size    rawsize  chainsize     ratio   lindist extradist extraratio   readsize largestblk rddensity srchunks
         0       1        1       -1    base         77        182         77   0.42308        77         0    0.00000         77         77   1.00000        1
         1       1        2        0      p1         21        191         98   0.51309        98         0    0.00000         98         98   1.00000        1
         2       1        3        1      p1         21        200        119   0.59500       119         0    0.00000        119        119   1.00000        1
   $ cd ..
 
   $ cat << EOF >> $HGRCPATH
   > [format]
   > maxchainlen = 9001
   > EOF
 
 Check upgrading a sparse-revlog repository
 ---------------------------------------
 
   $ hg init sparserevlogrepo --config format.sparse-revlog=no
   $ cd sparserevlogrepo
   $ touch foo
   $ hg add foo
   $ hg -q commit -m "foo"
   $ hg debugrequires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlogv1
   share-safe
   store
 
 Check that we can add the sparse-revlog format requirement
   $ hg --config format.sparse-revlog=yes debugupgraderepo --run --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, store (rust !)
      added: sparserevlog
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugrequires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlogv1
   share-safe
   sparserevlog
   store
 
 Check that we can remove the sparse-revlog format requirement
   $ hg --config format.sparse-revlog=no debugupgraderepo --run --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, store (rust !)
      removed: sparserevlog
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugrequires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlogv1
   share-safe
   store
 
 #if zstd
 
 Check upgrading to a zstd revlog
 --------------------------------
 
 upgrade
 
   $ hg --config format.revlog-compression=zstd debugupgraderepo --run  --no-backup --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, store (rust !)
      added: revlog-compression-zstd, sparserevlog
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   tracked-hint:        no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:         yes    yes     yes
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zstd   zlib    zstd (zstd !)
   compression-level:  default default default
   $ hg debugrequires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlog-compression-zstd
   revlogv1
   share-safe
   sparserevlog
   store
 
 downgrade
 
   $ hg debugupgraderepo --run --no-backup --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
      removed: revlog-compression-zstd
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   tracked-hint:        no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:         yes    yes     yes
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zlib   zlib    zstd (zstd !)
   compression-level:  default default default
   $ hg debugrequires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlogv1
   share-safe
   sparserevlog
   store
 
 upgrade from hgrc
 
   $ cat >> .hg/hgrc << EOF
   > [format]
   > revlog-compression=zstd
   > EOF
   $ hg debugupgraderepo --run --no-backup --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, revlogv1, share-safe, sparserevlog, store (no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlogv1, share-safe, sparserevlog, store (rust !)
      added: revlog-compression-zstd
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   tracked-hint:        no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:         yes    yes     yes
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zstd   zstd    zstd (zstd !)
   compression-level:  default default default
   $ hg debugrequires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlog-compression-zstd
   revlogv1
   share-safe
   sparserevlog
   store
 
 #endif
 
 Check upgrading to a revlog format supporting sidedata
 ------------------------------------------------------
 
 upgrade
 
   $ hg debugsidedata -c 0
   $ hg --config experimental.revlogv2=enable-unstable-format-and-corrupt-my-data debugupgraderepo --run  --no-backup --config "extensions.sidedata=$TESTDIR/testlib/ext-sidedata.py" --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, share-safe, store (no-zstd !)
      preserved: dotencode, fncache, generaldelta, revlog-compression-zstd, share-safe, sparserevlog, store (zstd no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlog-compression-zstd, share-safe, sparserevlog, store (rust !)
      removed: revlogv1
      added: exp-revlogv2.2 (zstd !)
      added: exp-revlogv2.2, sparserevlog (no-zstd !)
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   tracked-hint:        no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:         yes    yes     yes
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:          yes     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zstd   zstd    zstd (zstd !)
   compression-level:  default default default
   $ hg debugrequires
   dotencode
   exp-revlogv2.2
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlog-compression-zstd (zstd !)
   share-safe
   sparserevlog
   store
   $ hg debugsidedata -c 0
   2 sidedata entries
    entry-0001 size 4
    entry-0002 size 32
 
 downgrade
 
   $ hg debugupgraderepo --config experimental.revlogv2=no --run --no-backup --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, share-safe, sparserevlog, store (no-zstd !)
      preserved: dotencode, fncache, generaldelta, revlog-compression-zstd, share-safe, sparserevlog, store (zstd no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlog-compression-zstd, share-safe, sparserevlog, store (rust !)
      removed: exp-revlogv2.2
      added: revlogv1
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   tracked-hint:        no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:         yes    yes     yes
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:           no     no      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zstd   zstd    zstd (zstd !)
   compression-level:  default default default
   $ hg debugrequires
   dotencode
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlog-compression-zstd (zstd !)
   revlogv1
   share-safe
   sparserevlog
   store
   $ hg debugsidedata -c 0
 
 upgrade from hgrc
 
   $ cat >> .hg/hgrc << EOF
   > [experimental]
   > revlogv2=enable-unstable-format-and-corrupt-my-data
   > EOF
   $ hg debugupgraderepo --run --no-backup --quiet
   upgrade will perform the following actions:
   
   requirements
      preserved: dotencode, fncache, generaldelta, share-safe, sparserevlog, store (no-zstd !)
      preserved: dotencode, fncache, generaldelta, revlog-compression-zstd, share-safe, sparserevlog, store (zstd no-rust !)
      preserved: dotencode, fncache, generaldelta, persistent-nodemap, revlog-compression-zstd, share-safe, sparserevlog, store (rust !)
      removed: revlogv1
      added: exp-revlogv2.2
   
   processed revlogs:
     - all-filelogs
     - changelog
     - manifest
   
   $ hg debugformat -v
   format-variant     repo config default
   fncache:            yes    yes     yes
   dirstate-v2:         no     no      no
   tracked-hint:        no     no      no
   dotencode:          yes    yes     yes
   generaldelta:       yes    yes     yes
   share-safe:         yes    yes     yes
   sparserevlog:       yes    yes     yes
   persistent-nodemap:  no     no      no (no-rust !)
   persistent-nodemap: yes    yes      no (rust !)
   copies-sdc:          no     no      no
   revlog-v2:          yes    yes      no
   changelog-v2:        no     no      no
   plain-cl-delta:     yes    yes     yes
   compression:        zlib   zlib    zlib (no-zstd !)
   compression:        zstd   zstd    zstd (zstd !)
   compression-level:  default default default
   $ hg debugrequires
   dotencode
   exp-revlogv2.2
   fncache
   generaldelta
   persistent-nodemap (rust !)
   revlog-compression-zstd (zstd !)
   share-safe
   sparserevlog
   store
   $ hg debugsidedata -c 0
 
 Demonstrate that nothing to perform upgrade will still run all the way through
 
   $ hg debugupgraderepo --run
   nothing to do
 
 #if no-rust
 
   $ cat << EOF >> $HGRCPATH
   > [storage]
   > dirstate-v2.slow-path = allow
   > EOF
 
 #endif
 
 Upgrade to dirstate-v2
 
   $ hg debugformat -v --config format.use-dirstate-v2=1 | grep dirstate-v2
   dirstate-v2:         no    yes      no
   $ hg debugupgraderepo --config format.use-dirstate-v2=1 --run
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      added: dirstate-v2
   
   dirstate-v2
      "hg status" will be faster
   
   no revlogs to process
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/sparserevlogrepo/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   upgrading to dirstate-v2 from v1
   replaced files will be backed up at $TESTTMP/sparserevlogrepo/.hg/upgradebackup.* (glob)
   removing temporary repository $TESTTMP/sparserevlogrepo/.hg/upgrade.* (glob)
   $ ls .hg/upgradebackup.*/dirstate
   .hg/upgradebackup.*/dirstate (glob)
   $ hg debugformat -v | grep dirstate-v2
   dirstate-v2:        yes     no      no
   $ hg status
   $ dd bs=12 count=1 if=.hg/dirstate 2> /dev/null
   dirstate-v2
 
 Downgrade from dirstate-v2
 
   $ hg debugupgraderepo --run
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      removed: dirstate-v2
   
   no revlogs to process
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/sparserevlogrepo/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   downgrading from dirstate-v2 to v1
   replaced files will be backed up at $TESTTMP/sparserevlogrepo/.hg/upgradebackup.* (glob)
   removing temporary repository $TESTTMP/sparserevlogrepo/.hg/upgrade.* (glob)
   $ hg debugformat -v | grep dirstate-v2
   dirstate-v2:         no     no      no
   $ hg status
 
   $ cd ..
 
 dirstate-v2: upgrade and downgrade from and empty repository:
 -------------------------------------------------------------
 
   $ hg init --config format.use-dirstate-v2=no dirstate-v2-empty
   $ cd dirstate-v2-empty
   $ hg debugformat | grep dirstate-v2
   dirstate-v2:         no
 
 upgrade
 
   $ hg debugupgraderepo --run --config format.use-dirstate-v2=yes
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      added: dirstate-v2
   
   dirstate-v2
      "hg status" will be faster
   
   no revlogs to process
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/dirstate-v2-empty/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   upgrading to dirstate-v2 from v1
   replaced files will be backed up at $TESTTMP/dirstate-v2-empty/.hg/upgradebackup.* (glob)
   removing temporary repository $TESTTMP/dirstate-v2-empty/.hg/upgrade.* (glob)
   $ hg debugformat | grep dirstate-v2
   dirstate-v2:        yes
 
 downgrade
 
   $ hg debugupgraderepo --run --config format.use-dirstate-v2=no
   upgrade will perform the following actions:
   
   requirements
      preserved: * (glob)
      removed: dirstate-v2
   
   no revlogs to process
   
   beginning upgrade...
   repository locked and read-only
   creating temporary repository to stage upgraded data: $TESTTMP/dirstate-v2-empty/.hg/upgrade.* (glob)
   (it is safe to interrupt this process any time before data migration completes)
   downgrading from dirstate-v2 to v1
   replaced files will be backed up at $TESTTMP/dirstate-v2-empty/.hg/upgradebackup.* (glob)
   removing temporary repository $TESTTMP/dirstate-v2-empty/.hg/upgrade.* (glob)
   $ hg debugformat | grep dirstate-v2
   dirstate-v2:         no
 
   $ cd ..
 
 Test automatic upgrade/downgrade
 ================================
 
 
 For dirstate v2
 ---------------
 
 create an initial repository
 
   $ hg init auto-upgrade \
   >     --config format.use-dirstate-v2=no \
   >     --config format.use-dirstate-tracked-hint=yes \
   >     --config format.use-share-safe=no
   $ hg debugbuilddag -R auto-upgrade --new-file .+5
   $ hg -R auto-upgrade update
   6 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg debugformat -R auto-upgrade | grep dirstate-v2
   dirstate-v2:         no
 
 upgrade it to dirstate-v2 automatically
 
   $ hg status -R auto-upgrade \
   >     --config format.use-dirstate-v2.automatic-upgrade-of-mismatching-repositories=yes \
   >     --config format.use-dirstate-v2=yes
   automatically upgrading repository to the `dirstate-v2` feature
   (see `hg help config.format.use-dirstate-v2` for details)
   $ hg debugformat -R auto-upgrade | grep dirstate-v2
   dirstate-v2:        yes
 
 downgrade it from dirstate-v2 automatically
 
   $ hg status -R auto-upgrade \
   >     --config format.use-dirstate-v2.automatic-upgrade-of-mismatching-repositories=yes \
   >     --config format.use-dirstate-v2=no
   automatically downgrading repository from the `dirstate-v2` feature
   (see `hg help config.format.use-dirstate-v2` for details)
   $ hg debugformat -R auto-upgrade | grep dirstate-v2
   dirstate-v2:         no
 
 
 For multiple change at the same time
 ------------------------------------
 
   $ hg debugformat -R auto-upgrade | egrep '(dirstate-v2|tracked|share-safe)'
   dirstate-v2:         no
   tracked-hint:       yes
   share-safe:          no
 
   $ hg status -R auto-upgrade \
   >     --config format.use-dirstate-v2.automatic-upgrade-of-mismatching-repositories=yes \
   >     --config format.use-dirstate-v2=yes \
   >     --config format.use-dirstate-tracked-hint.automatic-upgrade-of-mismatching-repositories=yes \
   >     --config format.use-dirstate-tracked-hint=no\
   >     --config format.use-share-safe.automatic-upgrade-of-mismatching-repositories=yes \
   >     --config format.use-share-safe=yes
   automatically upgrading repository to the `dirstate-v2` feature
   (see `hg help config.format.use-dirstate-v2` for details)
   automatically upgrading repository to the `share-safe` feature
   (see `hg help config.format.use-share-safe` for details)
   automatically downgrading repository from the `tracked-hint` feature
   (see `hg help config.format.use-dirstate-tracked-hint` for details)
   $ hg debugformat -R auto-upgrade | egrep '(dirstate-v2|tracked|share-safe)'
   dirstate-v2:        yes
   tracked-hint:        no
   share-safe:         yes
 
+Attempting Auto-upgrade on a read-only repository
+-------------------------------------------------
+
+  $ chmod -R a-w auto-upgrade
+
+  $ hg status -R auto-upgrade \
+  >     --config format.use-dirstate-v2.automatic-upgrade-of-mismatching-repositories=yes \
+  >     --config format.use-dirstate-v2=no
+  abort: could not lock working directory of auto-upgrade: Permission denied
+  [20]
+  $ hg debugformat -R auto-upgrade | grep dirstate-v2
+  dirstate-v2:        yes
+
+  $ chmod -R u+w auto-upgrade
+