test: use a more direct form of interruption in fncache "recover" testing

The previous test was relying on implementation details and harder to maintain.

The new version is closer to the initial intend : "What happens if the process
die without cleanup".

This change is motivated by further changes around the transaction and dirstate
logic that would break the fragile equilibrium that existed before this patch.

Making this change early make it easier to review on its own and remove noise
in future larger changes.

tests/test-fncache.t

@@ -1,537 +1,537 b''
 #require repofncache
 
 An extension which will set fncache chunksize to 1 byte to make sure that logic
 does not break
 
   $ cat > chunksize.py <<EOF
   > from mercurial import store
   > store.fncache_chunksize = 1
   > EOF
 
   $ cat >> $HGRCPATH <<EOF
   > [extensions]
   > chunksize = $TESTTMP/chunksize.py
   > EOF
 
 Init repo1:
 
   $ hg init repo1
   $ cd repo1
   $ echo "some text" > a
   $ hg add
   adding a
   $ hg ci -m first
   $ cat .hg/store/fncache | sort
   data/a.i
 
 Testing a.i/b:
 
   $ mkdir a.i
   $ echo "some other text" > a.i/b
   $ hg add
   adding a.i/b
   $ hg ci -m second
   $ cat .hg/store/fncache | sort
   data/a.i
   data/a.i.hg/b.i
 
 Testing a.i.hg/c:
 
   $ mkdir a.i.hg
   $ echo "yet another text" > a.i.hg/c
   $ hg add
   adding a.i.hg/c
   $ hg ci -m third
   $ cat .hg/store/fncache | sort
   data/a.i
   data/a.i.hg.hg/c.i
   data/a.i.hg/b.i
 
 Testing verify:
 
   $ hg verify -q
 
   $ rm .hg/store/fncache
 
   $ hg verify
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
    warning: revlog 'data/a.i' not in fncache!
    warning: revlog 'data/a.i.hg/c.i' not in fncache!
    warning: revlog 'data/a.i/b.i' not in fncache!
   checking dirstate
   checked 3 changesets with 3 changes to 3 files
   3 warnings encountered!
   hint: run "hg debugrebuildfncache" to recover from corrupt fncache
 
 Follow the hint to make sure it works
 
   $ hg debugrebuildfncache
   adding data/a.i
   adding data/a.i.hg/c.i
   adding data/a.i/b.i
   3 items added, 0 removed from fncache
 
   $ hg verify -q
 
   $ cd ..
 
 Non store repo:
 
   $ hg --config format.usestore=False init foo
   $ cd foo
   $ mkdir tst.d
   $ echo foo > tst.d/foo
   $ hg ci -Amfoo
   adding tst.d/foo
   $ find .hg | sort
   .hg
   .hg/00changelog.i
   .hg/00manifest.i
   .hg/cache
   .hg/cache/branch2-served
   .hg/cache/rbc-names-v1
   .hg/cache/rbc-revs-v1
   .hg/data
   .hg/data/tst.d.hg
   .hg/data/tst.d.hg/foo.i
   .hg/dirstate
   .hg/fsmonitor.state (fsmonitor !)
   .hg/last-message.txt
   .hg/phaseroots
   .hg/requires
   .hg/undo
   .hg/undo.backup.dirstate
   .hg/undo.backupfiles
   .hg/undo.bookmarks
   .hg/undo.branch
   .hg/undo.desc
   .hg/undo.dirstate
   .hg/undo.phaseroots
   .hg/wcache
   .hg/wcache/checkisexec (execbit !)
   .hg/wcache/checklink (symlink !)
   .hg/wcache/checklink-target (symlink !)
   .hg/wcache/manifestfulltextcache (reporevlogstore !)
   $ cd ..
 
 Non fncache repo:
 
   $ hg --config format.usefncache=False init bar
   $ cd bar
   $ mkdir tst.d
   $ echo foo > tst.d/Foo
   $ hg ci -Amfoo
   adding tst.d/Foo
   $ find .hg | sort
   .hg
   .hg/00changelog.i
   .hg/cache
   .hg/cache/branch2-served
   .hg/cache/rbc-names-v1
   .hg/cache/rbc-revs-v1
   .hg/dirstate
   .hg/fsmonitor.state (fsmonitor !)
   .hg/last-message.txt
   .hg/requires
   .hg/store
   .hg/store/00changelog.i
   .hg/store/00manifest.i
   .hg/store/data
   .hg/store/data/tst.d.hg
   .hg/store/data/tst.d.hg/_foo.i
   .hg/store/phaseroots
   .hg/store/requires
   .hg/store/undo
   .hg/store/undo.backupfiles
   .hg/store/undo.phaseroots
   .hg/undo.backup.dirstate
   .hg/undo.bookmarks
   .hg/undo.branch
   .hg/undo.desc
   .hg/undo.dirstate
   .hg/wcache
   .hg/wcache/checkisexec (execbit !)
   .hg/wcache/checklink (symlink !)
   .hg/wcache/checklink-target (symlink !)
   .hg/wcache/manifestfulltextcache (reporevlogstore !)
   $ cd ..
 
 Encoding of reserved / long paths in the store
 
   $ hg init r2
   $ cd r2
   $ cat <<EOF > .hg/hgrc
   > [ui]
   > portablefilenames = ignore
   > EOF
 
   $ hg import -q --bypass - <<EOF
   > # HG changeset patch
   > # User test
   > # Date 0 0
   > # Node ID 1c7a2f7cb77be1a0def34e4c7cabc562ad98fbd7
   > # Parent  0000000000000000000000000000000000000000
   > 1
   > 
   > diff --git a/12345678/12345678/12345678/12345678/12345678/12345678/12345678/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-123456789-12.3456789-12345-ABCDEFGHIJKLMNOPRSTUVWXYZ-abcdefghjiklmnopqrstuvwxyz b/12345678/12345678/12345678/12345678/12345678/12345678/12345678/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-123456789-12.3456789-12345-ABCDEFGHIJKLMNOPRSTUVWXYZ-abcdefghjiklmnopqrstuvwxyz
   > new file mode 100644
   > --- /dev/null
   > +++ b/12345678/12345678/12345678/12345678/12345678/12345678/12345678/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-123456789-12.3456789-12345-ABCDEFGHIJKLMNOPRSTUVWXYZ-abcdefghjiklmnopqrstuvwxyz
   > @@ -0,0 +1,1 @@
   > +foo
   > diff --git a/AUX/SECOND/X.PRN/FOURTH/FI:FTH/SIXTH/SEVENTH/EIGHTH/NINETH/TENTH/ELEVENTH/LOREMIPSUM.TXT b/AUX/SECOND/X.PRN/FOURTH/FI:FTH/SIXTH/SEVENTH/EIGHTH/NINETH/TENTH/ELEVENTH/LOREMIPSUM.TXT
   > new file mode 100644
   > --- /dev/null
   > +++ b/AUX/SECOND/X.PRN/FOURTH/FI:FTH/SIXTH/SEVENTH/EIGHTH/NINETH/TENTH/ELEVENTH/LOREMIPSUM.TXT
   > @@ -0,0 +1,1 @@
   > +foo
   > diff --git a/Project Planning/Resources/AnotherLongDirectoryName/Followedbyanother/AndAnother/AndThenAnExtremelyLongFileName.txt b/Project Planning/Resources/AnotherLongDirectoryName/Followedbyanother/AndAnother/AndThenAnExtremelyLongFileName.txt
   > new file mode 100644
   > --- /dev/null
   > +++ b/Project Planning/Resources/AnotherLongDirectoryName/Followedbyanother/AndAnother/AndThenAnExtremelyLongFileName.txt	
   > @@ -0,0 +1,1 @@
   > +foo
   > diff --git a/bla.aux/prn/PRN/lpt/com3/nul/coma/foo.NUL/normal.c b/bla.aux/prn/PRN/lpt/com3/nul/coma/foo.NUL/normal.c
   > new file mode 100644
   > --- /dev/null
   > +++ b/bla.aux/prn/PRN/lpt/com3/nul/coma/foo.NUL/normal.c
   > @@ -0,0 +1,1 @@
   > +foo
   > diff --git a/enterprise/openesbaddons/contrib-imola/corba-bc/netbeansplugin/wsdlExtension/src/main/java/META-INF/services/org.netbeans.modules.xml.wsdl.bindingsupport.spi.ExtensibilityElementTemplateProvider b/enterprise/openesbaddons/contrib-imola/corba-bc/netbeansplugin/wsdlExtension/src/main/java/META-INF/services/org.netbeans.modules.xml.wsdl.bindingsupport.spi.ExtensibilityElementTemplateProvider
   > new file mode 100644
   > --- /dev/null
   > +++ b/enterprise/openesbaddons/contrib-imola/corba-bc/netbeansplugin/wsdlExtension/src/main/java/META-INF/services/org.netbeans.modules.xml.wsdl.bindingsupport.spi.ExtensibilityElementTemplateProvider
   > @@ -0,0 +1,1 @@
   > +foo
   > EOF
 
   $ find .hg/store -name *.i  | sort
   .hg/store/00changelog.i
   .hg/store/00manifest.i
   .hg/store/data/bla.aux/pr~6e/_p_r_n/lpt/co~6d3/nu~6c/coma/foo._n_u_l/normal.c.i
   .hg/store/dh/12345678/12345678/12345678/12345678/12345678/12345678/12345678/12345/xxxxxx168e07b38e65eff86ab579afaaa8e30bfbe0f35f.i
   .hg/store/dh/au~78/second/x.prn/fourth/fi~3afth/sixth/seventh/eighth/nineth/tenth/loremia20419e358ddff1bf8751e38288aff1d7c32ec05.i
   .hg/store/dh/enterpri/openesba/contrib-/corba-bc/netbeans/wsdlexte/src/main/java/org.net7018f27961fdf338a598a40c4683429e7ffb9743.i
   .hg/store/dh/project_/resource/anotherl/followed/andanoth/andthenanextremelylongfilename0d8e1f4187c650e2f1fdca9fd90f786bc0976b6b.i
 
   $ cd ..
 
 Aborting lock does not prevent fncache writes
 
   $ cat > exceptionext.py <<EOF
   > import os
   > from mercurial import commands, error, extensions
   > 
   > def lockexception(orig, vfs, lockname, wait, releasefn, *args, **kwargs):
   >     def releasewrap():
   >         l.held = False # ensure __del__ is a noop
   >         raise error.Abort(b"forced lock failure")
   >     l = orig(vfs, lockname, wait, releasewrap, *args, **kwargs)
   >     return l
   > 
   > def reposetup(ui, repo):
   >     extensions.wrapfunction(repo, '_lock', lockexception)
   > 
   > cmdtable = {}
   > 
   > # wrap "commit" command to prevent wlock from being '__del__()'-ed
   > # at the end of dispatching (for intentional "forced lcok failure")
   > def commitwrap(orig, ui, repo, *pats, **opts):
   >     repo = repo.unfiltered() # to use replaced repo._lock certainly
   >     wlock = repo.wlock()
   >     try:
   >         return orig(ui, repo, *pats, **opts)
   >     finally:
   >         # multiple 'relase()' is needed for complete releasing wlock,
   >         # because "forced" abort at last releasing store lock
   >         # prevents wlock from being released at same 'lockmod.release()'
   >         for i in range(wlock.held):
   >             wlock.release()
   > 
   > def extsetup(ui):
   >     extensions.wrapcommand(commands.table, b"commit", commitwrap)
   > EOF
   $ extpath=`pwd`/exceptionext.py
   $ hg init fncachetxn
   $ cd fncachetxn
   $ printf "[extensions]\nexceptionext=$extpath\n" >> .hg/hgrc
   $ touch y
   $ hg ci -qAm y
   abort: forced lock failure
   [255]
   $ cat .hg/store/fncache
   data/y.i
 
 Aborting transaction prevents fncache change
 
   $ cat > ../exceptionext.py <<EOF
   > import os
   > from mercurial import commands, error, extensions, localrepo
   > 
   > def wrapper(orig, self, *args, **kwargs):
   >     tr = orig(self, *args, **kwargs)
   >     def fail(tr):
   >         raise error.Abort(b"forced transaction failure")
   >     # zzz prefix to ensure it sorted after store.write
   >     tr.addfinalize(b'zzz-forcefails', fail)
   >     return tr
   > 
   > def uisetup(ui):
   >     extensions.wrapfunction(
   >         localrepo.localrepository, b'transaction', wrapper)
   > 
   > cmdtable = {}
   > 
   > EOF
 
 Clean cached version
   $ rm -f "${extpath}c"
   $ rm -Rf "`dirname $extpath`/__pycache__"
 
   $ touch z
   $ hg ci -qAm z
   transaction abort!
   rollback completed
   abort: forced transaction failure
   [255]
   $ cat .hg/store/fncache
   data/y.i
 
 Aborted transactions can be recovered later
 
   $ cat > ../exceptionext.py <<EOF
   > import os
+  > import signal
   > from mercurial import (
   >   commands,
   >   error,
   >   extensions,
   >   localrepo,
   >   transaction,
   > )
   > 
   > def trwrapper(orig, self, *args, **kwargs):
   >     tr = orig(self, *args, **kwargs)
   >     def fail(tr):
-  >         raise error.Abort(b"forced transaction failure")
+  >         os.kill(os.getpid(), signal.SIGKILL)
   >     # zzz prefix to ensure it sorted after store.write
   >     tr.addfinalize(b'zzz-forcefails', fail)
   >     return tr
   > 
-  > def abortwrapper(orig, self, *args, **kwargs):
-  >     raise error.Abort(b"forced transaction failure")
-  > 
   > def uisetup(ui):
   >     extensions.wrapfunction(localrepo.localrepository, 'transaction',
   >                             trwrapper)
-  >     extensions.wrapfunction(transaction.transaction, '_abort',
-  >                             abortwrapper)
   > 
   > cmdtable = {}
   > 
   > EOF
 
 Clean cached versions
   $ rm -f "${extpath}c"
   $ rm -Rf "`dirname $extpath`/__pycache__"
 
   $ hg up -q 1
   $ touch z
-  $ hg ci -qAm z 2>/dev/null
-  [255]
+# Cannot rely on the return code value as chg use a different one.
+# So we use a `|| echo` trick
+# XXX-CHG fixing chg behavior would be nice here.
+  $ hg ci -qAm z || echo "He's Dead, Jim." 2>/dev/null
+  Killed (?)
+  He's Dead, Jim.
   $ cat .hg/store/fncache | sort
   data/y.i
   data/z.i
   $ hg recover --verify
   rolling back interrupted transaction
   checking changesets
   checking manifests
   crosschecking files in changesets and manifests
   checking files
   checking dirstate
   checked 1 changesets with 1 changes to 1 files
   $ cat .hg/store/fncache
   data/y.i
 
   $ cd ..
 
 debugrebuildfncache does nothing unless repo has fncache requirement
 
   $ hg --config format.usefncache=false init nofncache
   $ cd nofncache
   $ hg debugrebuildfncache
   (not rebuilding fncache because repository does not support fncache)
 
   $ cd ..
 
 debugrebuildfncache works on empty repository
 
   $ hg init empty
   $ cd empty
   $ hg debugrebuildfncache
   fncache already up to date
   $ cd ..
 
 debugrebuildfncache on an up to date repository no-ops
 
   $ hg init repo
   $ cd repo
   $ echo initial > foo
   $ echo initial > .bar
   $ hg commit -A -m initial
   adding .bar
   adding foo
 
   $ cat .hg/store/fncache | sort
   data/.bar.i
   data/foo.i
 
   $ hg debugrebuildfncache
   fncache already up to date
 
 debugrebuildfncache restores deleted fncache file
 
   $ rm -f .hg/store/fncache
   $ hg debugrebuildfncache
   adding data/.bar.i
   adding data/foo.i
   2 items added, 0 removed from fncache
 
   $ cat .hg/store/fncache | sort
   data/.bar.i
   data/foo.i
 
 Rebuild after rebuild should no-op
 
   $ hg debugrebuildfncache
   fncache already up to date
 
 A single missing file should get restored, an extra file should be removed
 
   $ cat > .hg/store/fncache << EOF
   > data/foo.i
   > data/bad-entry.i
   > EOF
 
   $ hg debugrebuildfncache
   removing data/bad-entry.i
   adding data/.bar.i
   1 items added, 1 removed from fncache
 
   $ cat .hg/store/fncache | sort
   data/.bar.i
   data/foo.i
 
 debugrebuildfncache recovers from truncated line in fncache
 
   $ printf a > .hg/store/fncache
   $ hg debugrebuildfncache
   fncache does not ends with a newline
   adding data/.bar.i
   adding data/foo.i
   2 items added, 0 removed from fncache
 
   $ cat .hg/store/fncache | sort
   data/.bar.i
   data/foo.i
 
   $ cd ..
 
 Try a simple variation without dotencode to ensure fncache is ignorant of encoding
 
   $ hg --config format.dotencode=false init nodotencode
   $ cd nodotencode
   $ echo initial > foo
   $ echo initial > .bar
   $ hg commit -A -m initial
   adding .bar
   adding foo
 
   $ cat .hg/store/fncache | sort
   data/.bar.i
   data/foo.i
 
   $ rm .hg/store/fncache
   $ hg debugrebuildfncache
   adding data/.bar.i
   adding data/foo.i
   2 items added, 0 removed from fncache
 
   $ cat .hg/store/fncache | sort
   data/.bar.i
   data/foo.i
 
   $ cd ..
 
 In repositories that have accumulated a large number of files over time, the
 fncache file is going to be large. If we possibly can avoid loading it, so much the better.
 The cache should not loaded when committing changes to existing files, or when unbundling
 changesets that only contain changes to existing files:
 
   $ cat > fncacheloadwarn.py << EOF
   > from mercurial import extensions, localrepo
   > 
   > def extsetup(ui):
   >     def wrapstore(orig, requirements, *args):
   >         store = orig(requirements, *args)
   >         if b'store' in requirements and b'fncache' in requirements:
   >             instrumentfncachestore(store, ui)
   >         return store
   >     extensions.wrapfunction(localrepo, 'makestore', wrapstore)
   > 
   > def instrumentfncachestore(fncachestore, ui):
   >     class instrumentedfncache(type(fncachestore.fncache)):
   >         def _load(self):
   >             ui.warn(b'fncache load triggered!\n')
   >             super(instrumentedfncache, self)._load()
   >     fncachestore.fncache.__class__ = instrumentedfncache
   > EOF
 
   $ fncachextpath=`pwd`/fncacheloadwarn.py
   $ hg init nofncacheload
   $ cd nofncacheload
   $ printf "[extensions]\nfncacheloadwarn=$fncachextpath\n" >> .hg/hgrc
 
 A new file should trigger a load, as we'd want to update the fncache set in that case:
 
   $ touch foo
   $ hg ci -qAm foo
   fncache load triggered!
 
 But modifying that file should not:
 
   $ echo bar >> foo
   $ hg ci -qm foo
 
 If a transaction has been aborted, the zero-size truncated index file will
 not prevent the fncache from being loaded; rather than actually abort
 a transaction, we simulate the situation by creating a zero-size index file:
 
   $ touch .hg/store/data/bar.i
   $ touch bar
   $ hg ci -qAm bar
   fncache load triggered!
 
 Unbundling should follow the same rules; existing files should not cause a load:
 
 (loading during the clone is expected)
   $ hg clone -q . tobundle
   fncache load triggered!
   fncache load triggered!
 
   $ echo 'new line' > tobundle/bar
   $ hg -R tobundle ci -qm bar
   $ hg -R tobundle bundle -q barupdated.hg
   $ hg unbundle -q barupdated.hg
 
 but adding new files should:
 
   $ touch tobundle/newfile
   $ hg -R tobundle ci -qAm newfile
   $ hg -R tobundle bundle -q newfile.hg
   $ hg unbundle -q newfile.hg
   fncache load triggered!
 
   $ cd ..