context: check file exists before getting data from _wrappedctx
overlayworkingctx class is used to do in-memory merging. The data() function of
that class has logic to look for data() in the wrappedctx if the file data in
cache is empty and if the file is dirty. This assumes that if a file is dirty
and cache has empty data for it, it will exists in the _wrappedctx.
However this assumption can be False in case when we are merging a file which is
empty in destination. In these cases, the backup file 'foo.orig' created by our
internal merge algorithms will be empty, however it won't be present in
_wrappedctx. This case will lead us to error like the one this patch is fixing.
Let's only fallback to getting data from wrappedctx if cache has 'None' as data.
Differential Revision: https://phab.mercurial-scm.org/D6308
initial
$ hg init test-a
$ cd test-a
$ cat >test.txt <<"EOF"
> 1
> 2
> 3
> EOF
$ hg add test.txt
$ hg commit -m "Initial"
clone
$ cd ..
$ hg clone test-a test-b
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
change test-a
$ cd test-a
$ cat >test.txt <<"EOF"
> one
> two
> three
> EOF
$ hg commit -m "Numbers as words"
change test-b
$ cd ../test-b
$ cat >test.txt <<"EOF"
> 1
> 2.5
> 3
> EOF
$ hg commit -m "2 -> 2.5"
now pull and merge from test-a
$ hg pull ../test-a
pulling from ../test-a
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets 96b70246a118
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg merge
merging test.txt
warning: conflicts while merging test.txt! (edit, then use 'hg resolve --mark')
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
resolve conflict
$ cat >test.txt <<"EOF"
> one
> two-point-five
> three
> EOF
$ rm -f *.orig
$ hg resolve -m test.txt
(no more unresolved files)
$ hg commit -m "Merge 1"
change test-a again
$ cd ../test-a
$ cat >test.txt <<"EOF"
> one
> two-point-one
> three
> EOF
$ hg commit -m "two -> two-point-one"
pull and merge from test-a again
$ cd ../test-b
$ hg pull ../test-a
pulling from ../test-a
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets 40d11a4173a8
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg merge --debug
searching for copies back to rev 1
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: 96b70246a118, local: 50c3a7e29886+, remote: 40d11a4173a8
preserving test.txt for resolve of test.txt
starting 4 threads for background file closing (?)
test.txt: versions differ -> m (premerge)
picked tool ':merge' for test.txt (binary False symlink False changedelete False)
merging test.txt
my test.txt@50c3a7e29886+ other test.txt@40d11a4173a8 ancestor test.txt@96b70246a118
test.txt: versions differ -> m (merge)
picked tool ':merge' for test.txt (binary False symlink False changedelete False)
my test.txt@50c3a7e29886+ other test.txt@40d11a4173a8 ancestor test.txt@96b70246a118
warning: conflicts while merging test.txt! (edit, then use 'hg resolve --mark')
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
$ cat test.txt
one
<<<<<<< working copy: 50c3a7e29886 - test: Merge 1
two-point-five
=======
two-point-one
>>>>>>> merge rev: 40d11a4173a8 - test: two -> two-point-one
three
$ hg debugindex test.txt
rev linkrev nodeid p1 p2
0 0 01365c4cca56 000000000000 000000000000
1 1 7b013192566a 01365c4cca56 000000000000
2 2 8fe46a3eb557 01365c4cca56 000000000000
3 3 fc3148072371 7b013192566a 8fe46a3eb557
4 4 d40249267ae3 8fe46a3eb557 000000000000
$ hg log
changeset: 4:40d11a4173a8
tag: tip
parent: 2:96b70246a118
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: two -> two-point-one
changeset: 3:50c3a7e29886
parent: 1:d1e159716d41
parent: 2:96b70246a118
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Merge 1
changeset: 2:96b70246a118
parent: 0:b1832b9d912a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Numbers as words
changeset: 1:d1e159716d41
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 2 -> 2.5
changeset: 0:b1832b9d912a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: Initial
$ cd ..