filectx.parents: enforce changeid of parent to be in own changectx ancestors
Because of the way filenodes are computed, you can have multiple changesets
"introducing" the same file revision. For example, in the changeset graph
below, changeset 2 and 3 both change a file -to- and -from- the same content.
o 3: content = new
|
| o 2: content = new
|/
o 1: content = old
In such cases, the file revision is create once, when 2 is added, and just reused
for 3. So the file change in '3' (from "old" to "new)" has no linkrev pointing
to it). We'll call this situation "linkrev-shadowing". As the linkrev is used for
optimization purposes when walking a file history, the linkrev-shadowing
results in an unexpected jump to another branch during such a walk.. This leads to
multiple bugs with log, annotate and rename detection.
One element to fix such bugs is to ensure that walking the file history sticks on
the same topology as the changeset's history. For this purpose, we extend the
logic in 'basefilectx.parents' so that it always defines the proper changeset
to associate the parent file revision with. This "proper" changeset has to be an
ancestor of the changeset associated with the child file revision.
This logic is performed in the '_adjustlinkrev' function. This function is
given the starting changeset and all the information regarding the parent file
revision. If the linkrev for the file revision is an ancestor of the starting
changeset, the linkrev is valid and will be used. If it is not, we detected a
topological jump caused by linkrev shadowing, we are going to walk the
ancestors of the starting changeset until we find one setting the file to the
revision we are trying to create.
The performance impact appears acceptable:
- We are walking the changelog once for each filelog traversal (as there should
be no overlap between searches),
- changelog traversal itself is fairly cheap, compared to what is likely going
to be perform on the result on the filelog traversal,
- We only touch the manifest for ancestors touching the file, And such
changesets are likely to be the one introducing the file. (except in
pathological cases involving merge),
- We use manifest diff instead of full manifest unpacking to check manifest
content, so it does not involve applying multiple diffs in most case.
- linkrev shadowing is not the common case.
Tests for fixed issues in log, annotate and rename detection have been
added.
But this changeset does not solve all problems. It fixes -ancestry-
computation, but if the linkrev-shadowed changesets is the starting one, we'll
still get things wrong. We'll have to fix the bootstrapping of such operations
in a later changeset. Also, the usage of `hg log FILE` without --follow still
has issues with linkrev pointing to hidden changesets, because it relies on the
`filelog` revset which implement its own traversal logic that is still to be
fixed.
Thanks goes to:
- Matt Mackall: for nudging me in the right direction
- Julien Cristau and Rémi Cardona: for keep telling me linkrev bug were an
evolution show stopper for 3 years.
- Durham Goode: for finding a new linkrev issue every few weeks
- Mads Kiilerich: for that last rename bug who raise this topic over my
anoyance limit.
$ HGMERGE=true; export HGMERGE
$ echo '[extensions]' >> $HGRCPATH
$ echo 'convert =' >> $HGRCPATH
$ glog()
> {
> hg log -G --template '{rev} "{desc}" files: {files}\n' "$@"
> }
$ hg init source
$ cd source
$ echo foo > foo
$ echo baz > baz
$ mkdir -p dir/subdir
$ echo dir/file >> dir/file
$ echo dir/file2 >> dir/file2
$ echo dir/file3 >> dir/file3 # to be corrupted in rev 0
$ echo dir/subdir/file3 >> dir/subdir/file3
$ echo dir/subdir/file4 >> dir/subdir/file4
$ hg ci -d '0 0' -qAm '0: add foo baz dir/'
$ echo bar > bar
$ echo quux > quux
$ echo dir/file4 >> dir/file4 # to be corrupted in rev 1
$ hg copy foo copied
$ hg ci -d '1 0' -qAm '1: add bar quux; copy foo to copied'
$ echo >> foo
$ hg ci -d '2 0' -m '2: change foo'
$ hg up -qC 1
$ echo >> bar
$ echo >> quux
$ hg ci -d '3 0' -m '3: change bar quux'
created new head
$ hg up -qC 2
$ hg merge -qr 3
$ echo >> bar
$ echo >> baz
$ hg ci -d '4 0' -m '4: first merge; change bar baz'
$ echo >> bar
$ echo 1 >> baz
$ echo >> quux
$ hg ci -d '5 0' -m '5: change bar baz quux'
$ hg up -qC 4
$ echo >> foo
$ echo 2 >> baz
$ hg ci -d '6 0' -m '6: change foo baz'
created new head
$ hg up -qC 5
$ hg merge -qr 6
$ echo >> bar
$ hg ci -d '7 0' -m '7: second merge; change bar'
$ echo >> foo
$ hg ci -m '8: change foo'
$ glog
@ 8 "8: change foo" files: foo
|
o 7 "7: second merge; change bar" files: bar baz
|\
| o 6 "6: change foo baz" files: baz foo
| |
o | 5 "5: change bar baz quux" files: bar baz quux
|/
o 4 "4: first merge; change bar baz" files: bar baz
|\
| o 3 "3: change bar quux" files: bar quux
| |
o | 2 "2: change foo" files: foo
|/
o 1 "1: add bar quux; copy foo to copied" files: bar copied dir/file4 quux
|
o 0 "0: add foo baz dir/" files: baz dir/file dir/file2 dir/file3 dir/subdir/file3 dir/subdir/file4 foo
final file versions in this repo:
$ hg manifest --debug
9463f52fe115e377cf2878d4fc548117211063f2 644 bar
94c1be4dfde2ee8d78db8bbfcf81210813307c3d 644 baz
7711d36246cc83e61fb29cd6d4ef394c63f1ceaf 644 copied
3e20847584beff41d7cd16136b7331ab3d754be0 644 dir/file
75e6d3f8328f5f6ace6bf10b98df793416a09dca 644 dir/file2
e96dce0bc6a217656a3a410e5e6bec2c4f42bf7c 644 dir/file3
6edd55f559cdce67132b12ca09e09cee08b60442 644 dir/file4
5fe139720576e18e34bcc9f79174db8897c8afe9 644 dir/subdir/file3
57a1c1511590f3de52874adfa04effe8a77d64af 644 dir/subdir/file4
9a7b52012991e4873687192c3e17e61ba3e837a3 644 foo
bc3eca3f47023a3e70ca0d8cc95a22a6827db19d 644 quux
$ hg debugrename copied
copied renamed from foo:2ed2a3912a0b24502043eae84ee4b279c18b90dd
$ cd ..
Test interaction with startrev and verify that changing it is handled properly:
$ > empty
$ hg convert --filemap empty source movingstart --config convert.hg.startrev=3 -r4
initializing destination movingstart repository
scanning source...
sorting...
converting...
1 3: change bar quux
0 4: first merge; change bar baz
$ hg convert --filemap empty source movingstart
scanning source...
sorting...
converting...
3 5: change bar baz quux
2 6: change foo baz
1 7: second merge; change bar
warning: af455ce4166b3c9c88e6309c2b9332171dcea595 parent 61e22ca76c3b3e93df20338c4e02ce286898e825 is missing
warning: cf908b3eeedc301c9272ebae931da966d5b326c7 parent 59e1ab45c888289513b7354484dac8a88217beab is missing
0 8: change foo
splitrepo tests
$ splitrepo()
> {
> msg="$1"
> files="$2"
> opts=$3
> echo "% $files: $msg"
> prefix=`echo "$files" | sed -e 's/ /-/g'`
> fmap="$prefix.fmap"
> repo="$prefix.repo"
> for i in $files; do
> echo "include $i" >> "$fmap"
> done
> hg -q convert $opts --filemap "$fmap" --datesort source "$repo"
> hg up -q -R "$repo"
> glog -R "$repo"
> hg -R "$repo" manifest --debug
> }
$ splitrepo 'skip unwanted merges; use 1st parent in 1st merge, 2nd in 2nd' foo
% foo: skip unwanted merges; use 1st parent in 1st merge, 2nd in 2nd
@ 3 "8: change foo" files: foo
|
o 2 "6: change foo baz" files: foo
|
o 1 "2: change foo" files: foo
|
o 0 "0: add foo baz dir/" files: foo
9a7b52012991e4873687192c3e17e61ba3e837a3 644 foo
$ splitrepo 'merges are not merges anymore' bar
% bar: merges are not merges anymore
@ 4 "7: second merge; change bar" files: bar
|
o 3 "5: change bar baz quux" files: bar
|
o 2 "4: first merge; change bar baz" files: bar
|
o 1 "3: change bar quux" files: bar
|
o 0 "1: add bar quux; copy foo to copied" files: bar
9463f52fe115e377cf2878d4fc548117211063f2 644 bar
$ splitrepo '1st merge is not a merge anymore; 2nd still is' baz
% baz: 1st merge is not a merge anymore; 2nd still is
@ 4 "7: second merge; change bar" files: baz
|\
| o 3 "6: change foo baz" files: baz
| |
o | 2 "5: change bar baz quux" files: baz
|/
o 1 "4: first merge; change bar baz" files: baz
|
o 0 "0: add foo baz dir/" files: baz
94c1be4dfde2ee8d78db8bbfcf81210813307c3d 644 baz
$ splitrepo 'we add additional merges when they are interesting' 'foo quux'
% foo quux: we add additional merges when they are interesting
@ 8 "8: change foo" files: foo
|
o 7 "7: second merge; change bar" files:
|\
| o 6 "6: change foo baz" files: foo
| |
o | 5 "5: change bar baz quux" files: quux
|/
o 4 "4: first merge; change bar baz" files:
|\
| o 3 "3: change bar quux" files: quux
| |
o | 2 "2: change foo" files: foo
|/
o 1 "1: add bar quux; copy foo to copied" files: quux
|
o 0 "0: add foo baz dir/" files: foo
9a7b52012991e4873687192c3e17e61ba3e837a3 644 foo
bc3eca3f47023a3e70ca0d8cc95a22a6827db19d 644 quux
$ splitrepo 'partial conversion' 'bar quux' '-r 3'
% bar quux: partial conversion
@ 1 "3: change bar quux" files: bar quux
|
o 0 "1: add bar quux; copy foo to copied" files: bar quux
b79105bedc55102f394e90a789c9c380117c1b4a 644 bar
db0421cc6b685a458c8d86c7d5c004f94429ea23 644 quux
$ splitrepo 'complete the partial conversion' 'bar quux'
% bar quux: complete the partial conversion
@ 4 "7: second merge; change bar" files: bar
|
o 3 "5: change bar baz quux" files: bar quux
|
o 2 "4: first merge; change bar baz" files: bar
|
o 1 "3: change bar quux" files: bar quux
|
o 0 "1: add bar quux; copy foo to copied" files: bar quux
9463f52fe115e377cf2878d4fc548117211063f2 644 bar
bc3eca3f47023a3e70ca0d8cc95a22a6827db19d 644 quux
$ rm -r foo.repo
$ splitrepo 'partial conversion' 'foo' '-r 3'
% foo: partial conversion
@ 0 "0: add foo baz dir/" files: foo
2ed2a3912a0b24502043eae84ee4b279c18b90dd 644 foo
$ splitrepo 'complete the partial conversion' 'foo'
% foo: complete the partial conversion
@ 3 "8: change foo" files: foo
|
o 2 "6: change foo baz" files: foo
|
o 1 "2: change foo" files: foo
|
o 0 "0: add foo baz dir/" files: foo
9a7b52012991e4873687192c3e17e61ba3e837a3 644 foo
$ splitrepo 'copied file; source not included in new repo' copied
% copied: copied file; source not included in new repo
@ 0 "1: add bar quux; copy foo to copied" files: copied
2ed2a3912a0b24502043eae84ee4b279c18b90dd 644 copied
$ hg --cwd copied.repo debugrename copied
copied not renamed
$ splitrepo 'copied file; source included in new repo' 'foo copied'
% foo copied: copied file; source included in new repo
@ 4 "8: change foo" files: foo
|
o 3 "6: change foo baz" files: foo
|
o 2 "2: change foo" files: foo
|
o 1 "1: add bar quux; copy foo to copied" files: copied
|
o 0 "0: add foo baz dir/" files: foo
7711d36246cc83e61fb29cd6d4ef394c63f1ceaf 644 copied
9a7b52012991e4873687192c3e17e61ba3e837a3 644 foo
$ hg --cwd foo-copied.repo debugrename copied
copied renamed from foo:2ed2a3912a0b24502043eae84ee4b279c18b90dd
verify the top level 'include .' if there is no other includes:
$ echo "exclude something" > default.fmap
$ hg convert -q --filemap default.fmap -r1 source dummydest2
$ hg -R dummydest2 log --template '{rev} {node|short} {desc|firstline}\n'
1 61e22ca76c3b 1: add bar quux; copy foo to copied
0 c085cf2ee7fe 0: add foo baz dir/
$ echo "include somethingelse" >> default.fmap
$ hg convert -q --filemap default.fmap -r1 source dummydest3
$ hg -R dummydest3 log --template '{rev} {node|short} {desc|firstline}\n'
$ echo "include ." >> default.fmap
$ hg convert -q --filemap default.fmap -r1 source dummydest4
$ hg -R dummydest4 log --template '{rev} {node|short} {desc|firstline}\n'
1 61e22ca76c3b 1: add bar quux; copy foo to copied
0 c085cf2ee7fe 0: add foo baz dir/
ensure that the filemap contains duplicated slashes (issue3612)
$ cat > renames.fmap <<EOF
> include dir
> exclude dir/file2
> rename dir dir2//dir3
> include foo
> include copied
> rename foo foo2/
> rename copied ./copied2
> exclude dir/subdir
> include dir/subdir/file3
> EOF
$ rm source/.hg/store/data/dir/file3.i
$ rm source/.hg/store/data/dir/file4.i
$ hg -q convert --filemap renames.fmap --datesort source dummydest
abort: data/dir/file3.i@e96dce0bc6a2: no match found!
[255]
$ hg -q convert --filemap renames.fmap --datesort --config convert.hg.ignoreerrors=1 source renames.repo
ignoring: data/dir/file3.i@e96dce0bc6a2: no match found
ignoring: data/dir/file4.i@6edd55f559cd: no match found
$ hg up -q -R renames.repo
$ glog -R renames.repo
@ 4 "8: change foo" files: foo2
|
o 3 "6: change foo baz" files: foo2
|
o 2 "2: change foo" files: foo2
|
o 1 "1: add bar quux; copy foo to copied" files: copied2
|
o 0 "0: add foo baz dir/" files: dir2/dir3/file dir2/dir3/subdir/file3 foo2
$ hg -R renames.repo verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
4 files, 5 changesets, 7 total revisions
$ hg -R renames.repo manifest --debug
d43feacba7a4f1f2080dde4a4b985bd8a0236d46 644 copied2
3e20847584beff41d7cd16136b7331ab3d754be0 644 dir2/dir3/file
5fe139720576e18e34bcc9f79174db8897c8afe9 644 dir2/dir3/subdir/file3
9a7b52012991e4873687192c3e17e61ba3e837a3 644 foo2
$ hg --cwd renames.repo debugrename copied2
copied2 renamed from foo2:2ed2a3912a0b24502043eae84ee4b279c18b90dd
copied:
$ hg --cwd source cat copied
foo
copied2:
$ hg --cwd renames.repo cat copied2
foo
filemap errors
$ cat > errors.fmap <<EOF
> include dir/ # beware that comments changes error line numbers!
> exclude /dir
> rename dir//dir /dir//dir/ "out of sync"
> include
> EOF
$ hg -q convert --filemap errors.fmap source errors.repo
errors.fmap:3: superfluous / in include '/dir'
errors.fmap:3: superfluous / in rename '/dir'
errors.fmap:4: unknown directive 'out of sync'
errors.fmap:5: path to exclude is missing
abort: errors in filemap
[255]
test branch closing revision pruning if branch is pruned
$ hg init branchpruning
$ cd branchpruning
$ hg branch foo
marked working directory as branch foo
(branches are permanent and global, did you want a bookmark?)
$ echo a > a
$ hg ci -Am adda
adding a
$ hg ci --close-branch -m closefoo
$ hg up 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch empty
marked working directory as branch empty
(branches are permanent and global, did you want a bookmark?)
$ hg ci -m emptybranch
$ hg ci --close-branch -m closeempty
$ hg up 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch default
marked working directory as branch default
(branches are permanent and global, did you want a bookmark?)
$ echo b > b
$ hg ci -Am addb
adding b
$ hg ci --close-branch -m closedefault
$ cat > filemap <<EOF
> include b
> EOF
$ cd ..
$ hg convert branchpruning branchpruning-hg1
initializing destination branchpruning-hg1 repository
scanning source...
sorting...
converting...
5 adda
4 closefoo
3 emptybranch
2 closeempty
1 addb
0 closedefault
$ glog -R branchpruning-hg1
o 5 "closedefault" files:
|
o 4 "addb" files: b
|
| o 3 "closeempty" files:
| |
| o 2 "emptybranch" files:
|/
| o 1 "closefoo" files:
|/
o 0 "adda" files: a
exercise incremental conversion at the same time
$ hg convert -r0 --filemap branchpruning/filemap branchpruning branchpruning-hg2
initializing destination branchpruning-hg2 repository
scanning source...
sorting...
converting...
0 adda
$ hg convert -r4 --filemap branchpruning/filemap branchpruning branchpruning-hg2
scanning source...
sorting...
converting...
0 addb
$ hg convert --filemap branchpruning/filemap branchpruning branchpruning-hg2
scanning source...
sorting...
converting...
3 closefoo
2 emptybranch
1 closeempty
0 closedefault
$ glog -R branchpruning-hg2
o 1 "closedefault" files:
|
o 0 "addb" files: b
Test rebuilding of map with unknown revisions in shamap - it used to crash
$ cd branchpruning
$ hg up -r 2
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge 4
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m 'merging something'
$ cd ..
$ echo "53792d18237d2b64971fa571936869156655338d 6d955580116e82c4b029bd30f321323bae71a7f0" >> branchpruning-hg2/.hg/shamap
$ hg convert --filemap branchpruning/filemap branchpruning branchpruning-hg2 --debug
run hg source pre-conversion action
run hg sink pre-conversion action
scanning source...
scanning: 1 revisions
sorting...
converting...
0 merging something
source: 2503605b178fe50e8fbbb0e77b97939540aa8c87
converting: 0/1 revisions (0.00%)
unknown revmap source: 53792d18237d2b64971fa571936869156655338d
run hg sink post-conversion action
run hg source post-conversion action
filemap rename undoing revision rename
$ hg init renameundo
$ cd renameundo
$ echo 1 > a
$ echo 1 > c
$ hg ci -qAm add
$ hg mv -q a b/a
$ hg mv -q c b/c
$ hg ci -qm rename
$ echo 2 > b/a
$ echo 2 > b/c
$ hg ci -qm modify
$ cd ..
$ echo "rename b ." > renameundo.fmap
$ hg convert --filemap renameundo.fmap renameundo renameundo2
initializing destination renameundo2 repository
scanning source...
sorting...
converting...
2 add
1 rename
filtering out empty revision
repository tip rolled back to revision 0 (undo commit)
0 modify
$ glog -R renameundo2
o 1 "modify" files: a c
|
o 0 "add" files: a c
test merge parents/empty merges pruning
$ glog()
> {
> hg log -G --template '{rev}:{node|short}@{branch} "{desc}" files: {files}\n' "$@"
> }
test anonymous branch pruning
$ hg init anonymousbranch
$ cd anonymousbranch
$ echo a > a
$ echo b > b
$ hg ci -Am add
adding a
adding b
$ echo a >> a
$ hg ci -m changea
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo b >> b
$ hg ci -m changeb
created new head
$ hg up 1
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m merge
$ cd ..
$ cat > filemap <<EOF
> include a
> EOF
$ hg convert --filemap filemap anonymousbranch anonymousbranch-hg
initializing destination anonymousbranch-hg repository
scanning source...
sorting...
converting...
3 add
2 changea
1 changeb
0 merge
$ glog -R anonymousbranch
@ 3:c71d5201a498@default "merge" files:
|\
| o 2:607eb44b17f9@default "changeb" files: b
| |
o | 1:1f60ea617824@default "changea" files: a
|/
o 0:0146e6129113@default "add" files: a b
$ glog -R anonymousbranch-hg
o 1:cda818e7219b@default "changea" files: a
|
o 0:c334dc3be0da@default "add" files: a
$ cat anonymousbranch-hg/.hg/shamap
0146e6129113dba9ac90207cfdf2d7ed35257ae5 c334dc3be0daa2a4e9ce4d2e2bdcba40c09d4916
1f60ea61782421edf8d051ff4fcb61b330f26a4a cda818e7219b5f7f3fb9f49780054ed6a1905ec3
607eb44b17f9348cd5cbd26e16af87ba77b0b037 c334dc3be0daa2a4e9ce4d2e2bdcba40c09d4916
c71d5201a498b2658d105a6bf69d7a0df2649aea cda818e7219b5f7f3fb9f49780054ed6a1905ec3
$ cat > filemap <<EOF
> include b
> EOF
$ hg convert --filemap filemap anonymousbranch anonymousbranch-hg2
initializing destination anonymousbranch-hg2 repository
scanning source...
sorting...
converting...
3 add
2 changea
1 changeb
0 merge
$ glog -R anonymousbranch
@ 3:c71d5201a498@default "merge" files:
|\
| o 2:607eb44b17f9@default "changeb" files: b
| |
o | 1:1f60ea617824@default "changea" files: a
|/
o 0:0146e6129113@default "add" files: a b
$ glog -R anonymousbranch-hg2
o 1:62dd350b0df6@default "changeb" files: b
|
o 0:4b9ced861657@default "add" files: b
$ cat anonymousbranch-hg2/.hg/shamap
0146e6129113dba9ac90207cfdf2d7ed35257ae5 4b9ced86165703791653059a1db6ed864630a523
1f60ea61782421edf8d051ff4fcb61b330f26a4a 4b9ced86165703791653059a1db6ed864630a523
607eb44b17f9348cd5cbd26e16af87ba77b0b037 62dd350b0df695f7d2c82a02e0499b16fd790f22
c71d5201a498b2658d105a6bf69d7a0df2649aea 62dd350b0df695f7d2c82a02e0499b16fd790f22
test named branch pruning
$ hg init namedbranch
$ cd namedbranch
$ echo a > a
$ echo b > b
$ hg ci -Am add
adding a
adding b
$ echo a >> a
$ hg ci -m changea
$ hg up 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg branch foo
marked working directory as branch foo
(branches are permanent and global, did you want a bookmark?)
$ echo b >> b
$ hg ci -m changeb
$ hg up default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge foo
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m merge
$ cd ..
$ cat > filemap <<EOF
> include a
> EOF
$ hg convert --filemap filemap namedbranch namedbranch-hg
initializing destination namedbranch-hg repository
scanning source...
sorting...
converting...
3 add
2 changea
1 changeb
0 merge
$ glog -R namedbranch
@ 3:73899bcbe45c@default "merge" files:
|\
| o 2:8097982d19fc@foo "changeb" files: b
| |
o | 1:1f60ea617824@default "changea" files: a
|/
o 0:0146e6129113@default "add" files: a b
$ glog -R namedbranch-hg
o 1:cda818e7219b@default "changea" files: a
|
o 0:c334dc3be0da@default "add" files: a
$ cd namedbranch
$ hg --config extensions.mq= strip tip
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
saved backup bundle to $TESTTMP/namedbranch/.hg/strip-backup/73899bcbe45c-backup.hg (glob)
$ hg up foo
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -m merge
$ cd ..
$ hg convert --filemap filemap namedbranch namedbranch-hg2
initializing destination namedbranch-hg2 repository
scanning source...
sorting...
converting...
3 add
2 changea
1 changeb
0 merge
$ glog -R namedbranch
@ 3:e1959de76e1b@foo "merge" files:
|\
| o 2:8097982d19fc@foo "changeb" files: b
| |
o | 1:1f60ea617824@default "changea" files: a
|/
o 0:0146e6129113@default "add" files: a b
$ glog -R namedbranch-hg2
o 2:dcf314454667@foo "merge" files:
|\
| o 1:cda818e7219b@default "changea" files: a
|/
o 0:c334dc3be0da@default "add" files: a