tests: add test for updating to null revision

While working on merge.py, I realized that we don't (as far as I could
tell) have any tests for updating to the null revision with a dirty
working copy. This adds some simple tests for that.

tests/test-update-branches.t

@@ -1,392 +1,414 b''
 # Construct the following history tree:
 #
 # @  5:e1bb631146ca  b1
 # |
 # o  4:a4fdb3b883c4 0:b608b9236435  b1
 # |
 # | o  3:4b57d2520816 1:44592833ba9f
 # | |
 # | | o  2:063f31070f65
 # | |/
 # | o  1:44592833ba9f
 # |/
 # o  0:b608b9236435
 
   $ mkdir b1
   $ cd b1
   $ hg init
   $ echo foo > foo
   $ echo zero > a
   $ hg init sub
   $ echo suba > sub/suba
   $ hg --cwd sub ci -Am addsuba
   adding suba
   $ echo 'sub = sub' > .hgsub
   $ hg ci -qAm0
   $ echo one > a ; hg ci -m1
   $ echo two > a ; hg ci -m2
   $ hg up -q 1
   $ echo three > a ; hg ci -qm3
   $ hg up -q 0
   $ hg branch -q b1
   $ echo four > a ; hg ci -qm4
   $ echo five > a ; hg ci -qm5
 
 Initial repo state:
 
   $ hg log -G --template '{rev}:{node|short} {parents} {branches}\n'
   @  5:ff252e8273df  b1
   |
   o  4:d047485b3896 0:60829823a42a  b1
   |
   | o  3:6efa171f091b 1:0786582aa4b1
   | |
   | | o  2:bd10386d478c
   | |/
   | o  1:0786582aa4b1
   |/
   o  0:60829823a42a
   
 
 Make sure update doesn't assume b1 is a repository if invoked from outside:
 
   $ cd ..
   $ hg update b1
   abort: no repository found in '$TESTTMP' (.hg not found)!
   [255]
   $ cd b1
 
 Test helper functions:
 
   $ revtest () {
   >     msg=$1
   >     dirtyflag=$2   # 'clean', 'dirty' or 'dirtysub'
   >     startrev=$3
   >     targetrev=$4
   >     opt=$5
   >     hg up -qC $startrev
   >     test $dirtyflag = dirty && echo dirty > foo
   >     test $dirtyflag = dirtysub && echo dirty > sub/suba
   >     hg up $opt $targetrev
   >     hg parent --template 'parent={rev}\n'
   >     hg stat -S
   > }
 
   $ norevtest () {
   >     msg=$1
   >     dirtyflag=$2   # 'clean', 'dirty' or 'dirtysub'
   >     startrev=$3
   >     opt=$4
   >     hg up -qC $startrev
   >     test $dirtyflag = dirty && echo dirty > foo
   >     test $dirtyflag = dirtysub && echo dirty > sub/suba
   >     hg up $opt
   >     hg parent --template 'parent={rev}\n'
   >     hg stat -S
   > }
 
 Test cases are documented in a table in the update function of merge.py.
 Cases are run as shown in that table, row by row.
 
   $ norevtest 'none clean linear' clean 4
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   parent=5
 
   $ norevtest 'none clean same'   clean 2
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   1 other heads for branch "default"
   parent=2
 
 
   $ revtest 'none clean linear' clean 1 2
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   parent=2
 
   $ revtest 'none clean same'   clean 2 3
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   parent=3
 
   $ revtest 'none clean cross'  clean 3 4
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   parent=4
 
 
   $ revtest 'none dirty linear' dirty 1 2
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   parent=2
   M foo
 
   $ revtest 'none dirtysub linear' dirtysub 1 2
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   parent=2
   M sub/suba
 
   $ revtest 'none dirty same'   dirty 2 3
   abort: uncommitted changes
   (commit or update --clean to discard changes)
   parent=2
   M foo
 
   $ revtest 'none dirtysub same'   dirtysub 2 3
   abort: uncommitted changes
   (commit or update --clean to discard changes)
   parent=2
   M sub/suba
 
   $ revtest 'none dirty cross'  dirty 3 4
   abort: uncommitted changes
   (commit or update --clean to discard changes)
   parent=3
   M foo
 
   $ norevtest 'none dirty cross'  dirty 2
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   1 other heads for branch "default"
   parent=2
   M foo
 
   $ revtest 'none dirtysub cross'  dirtysub 3 4
   abort: uncommitted changes
   (commit or update --clean to discard changes)
   parent=3
   M sub/suba
 
   $ revtest '-C dirty linear'   dirty 1 2 -C
   2 files updated, 0 files merged, 0 files removed, 0 files unresolved
   parent=2
 
   $ revtest '-c dirty linear'   dirty 1 2 -c
   abort: uncommitted changes
   parent=1
   M foo
 
   $ revtest '-c dirtysub linear'   dirtysub 1 2 -c
   abort: uncommitted changes in subrepository 'sub'
   parent=1
   M sub/suba
 
   $ norevtest '-c clean same'   clean 2 -c
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   1 other heads for branch "default"
   parent=2
 
   $ revtest '-cC dirty linear'  dirty 1 2 -cC
   abort: cannot specify both -c/--check and -C/--clean
   parent=1
   M foo
 
   $ cd ..
 
+Test updating to null revision
+
+  $ hg init null-repo
+  $ cd null-repo
+  $ echo a > a
+  $ hg add a
+  $ hg ci -m a
+  $ hg up -qC 0
+  $ echo b > b
+  $ hg add b
+  $ hg up null
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ hg st
+  A b
+  $ hg up -q 0
+  $ hg st
+  A b
+  $ hg up -qC null
+  $ hg st
+  ? b
+  $ cd ..
+
 Test updating with closed head
 ---------------------------------------------------------------------
 
   $ hg clone -U -q b1 closed-heads
   $ cd closed-heads
 
 Test updating if at least one non-closed branch head exists
 
 if on the closed branch head:
 - update to "."
 - "updated to a closed branch head ...." message is displayed
 - "N other heads for ...." message is displayed
 
   $ hg update -q -C 3
   $ hg commit --close-branch -m 6
   $ norevtest "on closed branch head" clean 6
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   no open descendant heads on branch "default", updating to a closed head
   (committing will reopen the head, use 'hg heads .' to see 1 other heads)
   parent=6
 
 if descendant non-closed branch head exists, and it is only one branch head:
 - update to it, even if its revision is less than closed one
 - "N other heads for ...." message isn't displayed
 
   $ norevtest "non-closed 2 should be chosen" clean 1
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   parent=2
 
 if all descendant branch heads are closed, but there is another branch head:
 - update to the tipmost descendant head
 - "updated to a closed branch head ...." message is displayed
 - "N other heads for ...." message is displayed
 
   $ norevtest "all descendant branch heads are closed" clean 3
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   no open descendant heads on branch "default", updating to a closed head
   (committing will reopen the head, use 'hg heads .' to see 1 other heads)
   parent=6
 
 Test updating if all branch heads are closed
 
 if on the closed branch head:
 - update to "."
 - "updated to a closed branch head ...." message is displayed
 - "all heads of branch ...." message is displayed
 
   $ hg update -q -C 2
   $ hg commit --close-branch -m 7
   $ norevtest "all heads of branch default are closed" clean 6
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   no open descendant heads on branch "default", updating to a closed head
   (committing will reopen branch "default")
   parent=6
 
 if not on the closed branch head:
 - update to the tipmost descendant (closed) head
 - "updated to a closed branch head ...." message is displayed
 - "all heads of branch ...." message is displayed
 
   $ norevtest "all heads of branch default are closed" clean 1
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   no open descendant heads on branch "default", updating to a closed head
   (committing will reopen branch "default")
   parent=7
 
   $ cd ..
 
 Test updating if "default" branch doesn't exist and no revision is
 checked out (= "default" is used as current branch)
 
   $ hg init no-default-branch
   $ cd no-default-branch
 
   $ hg branch foobar
   marked working directory as branch foobar
   (branches are permanent and global, did you want a bookmark?)
   $ echo a > a
   $ hg commit -m "#0" -A
   adding a
   $ echo 1 >> a
   $ hg commit -m "#1"
   $ hg update -q 0
   $ echo 3 >> a
   $ hg commit -m "#2"
   created new head
   $ hg commit --close-branch -m "#3"
 
 if there is at least one non-closed branch head:
 - update to the tipmost branch head
 
   $ norevtest "non-closed 1 should be chosen" clean null
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   parent=1
 
 if all branch heads are closed
 - update to "tip"
 - "updated to a closed branch head ...." message is displayed
 - "all heads for branch "XXXX" are closed" message is displayed
 
   $ hg update -q -C 1
   $ hg commit --close-branch -m "#4"
 
   $ norevtest "all branches are closed" clean null
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   no open descendant heads on branch "foobar", updating to a closed head
   (committing will reopen branch "foobar")
   parent=4
 
   $ cd ../b1
 
 Test obsolescence behavior
 ---------------------------------------------------------------------
 
 successors should be taken in account when checking head destination
 
   $ cat << EOF >> $HGRCPATH
   > [ui]
   > logtemplate={rev}:{node|short} {desc|firstline}
   > [experimental]
   > evolution=createmarkers
   > EOF
 
 Test no-argument update to a successor of an obsoleted changeset
 
   $ hg log -G
   o  5:ff252e8273df 5
   |
   o  4:d047485b3896 4
   |
   | o  3:6efa171f091b 3
   | |
   | | o  2:bd10386d478c 2
   | |/
   | @  1:0786582aa4b1 1
   |/
   o  0:60829823a42a 0
   
   $ hg book bm -r 3
   $ hg status
   M foo
 
 We add simple obsolescence marker between 3 and 4 (indirect successors)
 
   $ hg id --debug -i -r 3
   6efa171f091b00a3c35edc15d48c52a498929953
   $ hg id --debug -i -r 4
   d047485b3896813b2a624e86201983520f003206
   $ hg debugobsolete 6efa171f091b00a3c35edc15d48c52a498929953 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
   $ hg debugobsolete aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa d047485b3896813b2a624e86201983520f003206
 
 Test that 5 is detected as a valid destination from 3 and also accepts moving
 the bookmark (issue4015)
 
   $ hg up --quiet --hidden 3
   $ hg up 5
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg book bm
   moving bookmark 'bm' forward from 6efa171f091b
   $ hg bookmarks
    * bm                        5:ff252e8273df
 
 Test that 4 is detected as the no-argument destination from 3 and also moves
 the bookmark with it
   $ hg up --quiet 0          # we should be able to update to 3 directly
   $ hg up --quiet --hidden 3 # but not implemented yet.
   $ hg book -f bm
   $ hg up
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   updating bookmark bm
   $ hg book
    * bm                        4:d047485b3896
 
 Test that 5 is detected as a valid destination from 1
   $ hg up --quiet 0          # we should be able to update to 3 directly
   $ hg up --quiet --hidden 3 # but not implemented yet.
   $ hg up 5
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
 Test that 5 is not detected as a valid destination from 2
   $ hg up --quiet 0
   $ hg up --quiet 2
   $ hg up 5
   abort: uncommitted changes
   (commit or update --clean to discard changes)
   [255]
 
 Test that we don't crash when updating from a pruned changeset (i.e. has no
 successors). Behavior should probably be that we update to the first
 non-obsolete parent but that will be decided later.
   $ hg id --debug -r 2
   bd10386d478cd5a9faf2e604114c8e6da62d3889
   $ hg up --quiet 0
   $ hg up --quiet 2
   $ hg debugobsolete bd10386d478cd5a9faf2e604114c8e6da62d3889
   $ hg up
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
 Test experimental revset support
 
   $ hg log -r '_destupdate()'
   2:bd10386d478c 2 (no-eol)
 
 Test that boolean flags allow --no-flag specification to override [defaults]
   $ cat >> $HGRCPATH <<EOF
   > [defaults]
   > update = --check
   > EOF
   $ hg co 2
   abort: uncommitted changes
   [255]
   $ hg co --no-check 2
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved