lfs: allow a pointer to be extracted from a context that removes the file
This is needed to let 'set:lfs()' and '{lfs_files}' work normally on removed
files.
Yuya suggested returning a null pointer for removed files, instead of the
pointer from the parent. The first attempt at this was to return None for a non
LFS file, and a (pointer, ctx) tuple to hold the pointer and context (or parent
pointer and context for a removed file). But this complicated the callers, even
the ones that didn't care about removed files.
Instead, let's use {} to represent a removed pointer. This has the added
convenience of being a useful representation in the template language, and only
affects the callers that care about removed files (and only slightly). Since
pointers are explicitly serialized with a call to a member function, there is no
danger of writing these to disk.
Set up repo
$ cat << EOF >> $HGRCPATH
> [ui]
> origbackuppath=.hg/origbackups
> [merge]
> checkunknown=warn
> EOF
$ hg init repo
$ cd repo
$ echo base > base
$ hg add base
$ hg commit -m "base"
Make a dir named b that contains a file, and a file named d
$ mkdir -p b
$ echo c1 > b/c
$ echo d1 > d
$ hg add b/c d
$ hg commit -m "c1"
$ hg bookmark c1
Peform an update that causes b/c to be backed up
$ hg up -q 0
$ mkdir -p b
$ echo c2 > b/c
$ hg up --verbose c1
resolving manifests
b/c: replacing untracked file
getting b/c
creating directory: $TESTTMP/repo/.hg/origbackups/b
getting d
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark c1)
$ test -f .hg/origbackups/b/c
Make files named b and d
$ hg up -q 0
$ echo b1 > b
$ echo d2 > d
$ hg add b d
$ hg commit -m b1
created new head
$ hg bookmark b1
Perform an update that causes b to be backed up - it should replace the backup b dir
$ hg up -q 0
$ echo b2 > b
$ hg up --verbose b1
resolving manifests
b: replacing untracked file
getting b
removing conflicting directory: $TESTTMP/repo/.hg/origbackups/b
getting d
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark b1)
$ test -f .hg/origbackups/b
Perform an update the causes b/c to be backed up again - it should replace the backup b file
$ hg up -q 0
$ mkdir b
$ echo c3 > b/c
$ hg up --verbose c1
resolving manifests
b/c: replacing untracked file
getting b/c
creating directory: $TESTTMP/repo/.hg/origbackups/b
removing conflicting file: $TESTTMP/repo/.hg/origbackups/b
getting d
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark c1)
$ test -d .hg/origbackups/b
Cause two symlinks to be backed up that points to a valid location from the backup dir
$ hg up -q 0
$ mkdir ../sym-link-target
#if symlink
$ ln -s ../../../sym-link-target b
$ ln -s ../../../sym-link-target d
#else
$ touch b d
#endif
$ hg up b1
b: replacing untracked file
d: replacing untracked file
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark b1)
#if symlink
$ readlink.py .hg/origbackups/b
.hg/origbackups/b -> ../../../sym-link-target
#endif
Perform an update that causes b/c and d to be backed up again - b/c should not go into the target dir
$ hg up -q 0
$ mkdir b
$ echo c4 > b/c
$ echo d3 > d
$ hg up --verbose c1
resolving manifests
b/c: replacing untracked file
d: replacing untracked file
getting b/c
creating directory: $TESTTMP/repo/.hg/origbackups/b
removing conflicting file: $TESTTMP/repo/.hg/origbackups/b
getting d
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark c1)
$ cat .hg/origbackups/b/c
c4
$ cat .hg/origbackups/d
d3
$ ls ../sym-link-target
Incorrectly configure origbackuppath to be under a file
$ echo data > .hg/badorigbackups
$ hg up -q 0
$ mkdir b
$ echo c5 > b/c
$ hg up --verbose c1 --config ui.origbackuppath=.hg/badorigbackups
resolving manifests
b/c: replacing untracked file
getting b/c
creating directory: $TESTTMP/repo/.hg/badorigbackups/b
abort: $ENOTDIR$: '$TESTTMP/repo/.hg/badorigbackups/b'
[255]
$ cat .hg/badorigbackups
data