[RFC/PATCH 0/2] git diff <(command1) <(command2)

Today on #git, a user asked why git diff <(command1) <(command2) gave only some gibberish about pipes as output. The answer is fairly simple: git diff gets as arguments /dev/fd/62 and /dev/fd/63, which are symlinks. So git simply readlink()s them and gets pipe:[123456] as destination of that link which it then outputs.

Given that 'normal' diff provides arguably better output in this case (a diff of the output of the two commands), I wanted to look at what it would take for git to handle this. Surprisingly: not much. 1/2 adds support for --follow-symlinks to git diff --no-index (and only the --no-index variant) and 2/2 adds support for reading from pipes.

No tests or documentation updates yet, and I'm not sure whether --follow-symlinks in other modes than --no-index should be supported, ignored (as it is now) or cause an error, but I'm leaning towards the third option.

Dennis Kaarsemaker (2):
  diff --no-index: add option to follow symlinks
  diff --no-index: support reading from pipes

 diff-no-index.c | 15 ++++++++++++---
 diff.c          | 23 +++++++++++++++++++----
 diff.h          |  2 +-
 3 files changed, 32 insertions(+), 8 deletions(-)