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.
$ cat > writepatterns.py <<EOF
> import sys
>
> path = sys.argv[1]
> patterns = sys.argv[2:]
>
> fp = file(path, 'wb')
> for pattern in patterns:
> count = int(pattern[0:-1])
> char = pattern[-1] + '\n'
> fp.write(char*count)
> fp.close()
> EOF
prepare repo
$ hg init a
$ cd a
These initial lines of Xs were not in the original file used to generate
the patch. So all the patch hunks need to be applied to a constant offset
within this file. If the offset isn't tracked then the hunks can be
applied to the wrong lines of this file.
$ $PYTHON ../writepatterns.py a 34X 10A 1B 10A 1C 10A 1B 10A 1D 10A 1B 10A 1E 10A 1B 10A
$ hg commit -Am adda
adding a
This is a cleaner patch generated via diff
In this case it reproduces the problem when
the output of hg export does not
import patch
$ hg import -v -m 'b' -d '2 0' - <<EOF
> --- a/a 2009-12-08 19:26:17.000000000 -0800
> +++ b/a 2009-12-08 19:26:17.000000000 -0800
> @@ -9,7 +9,7 @@
> A
> A
> B
> -A
> +a
> A
> A
> A
> @@ -53,7 +53,7 @@
> A
> A
> B
> -A
> +a
> A
> A
> A
> @@ -75,7 +75,7 @@
> A
> A
> B
> -A
> +a
> A
> A
> A
> EOF
applying patch from stdin
patching file a
Hunk #1 succeeded at 43 (offset 34 lines).
Hunk #2 succeeded at 87 (offset 34 lines).
Hunk #3 succeeded at 109 (offset 34 lines).
committing files:
a
committing manifest
committing changelog
created 189885cecb41
compare imported changes against reference file
$ $PYTHON ../writepatterns.py aref 34X 10A 1B 1a 9A 1C 10A 1B 10A 1D 10A 1B 1a 9A 1E 10A 1B 1a 9A
$ diff aref a
$ cd ..