[PATCH 0/1] git-p4: add format-patch subcommand

This is an initial attempt to add a "format-patch" command to git-p4, following on from the earlier discussion about shelving.

It uses the "p4 describe" command to generate the diff content and post-processes it enough to generate git-style patches. These can be fed to tools such as patch, or "git am".

This is useful for "unshelving" a P4 changelist into your git tree, since the usual git subcommands (sync, clone) cannot easily read a shelved changelist: there is no good way to get from Perforce a consistent single revision against which to generate a diff using git fast-import, since Perforce doesn't have the concept of a repo revision.

By default, it leaves the depot prefix in the patch, but using the option "--strip-depot-prefix" makes it suitable for "git am".

Use it like this:

 $ git p4 format-patch 12345 >out.patch

or
 $ mkdir patches
 $ git p4 format-patch --output patches 12345 12346

or
 $ git p4 format-patch --strip-depot-prefix 12347 >out.patch
 $ git am out.patch

Limitations of "p4 describe" mean that this will not work reliably with binary files. There's no easy way around this. The change makes a small attempt to at least stop on binary files, but in the case of a file marked in P4 as "text", which contains binary deltas, the file will unavoidably come out corrupted.

Luke Diamand (1):
  git-p4: add format-patch subcommand

 Documentation/git-p4.txt |  33 +++++
 git-p4.py                | 304 +++++++++++++++++++++++++++++++++++++++++++++--
 t/t9832-make-patch.sh    | 135 +++++++++++++++++++++
 3 files changed, 462 insertions(+), 10 deletions(-)
 create mode 100755 t/t9832-make-patch.sh