Fix "git diff --stat" for interesting - but empty - file changes

The behavior of "git diff --stat" is rather odd for files that have
zero lines of changes: it will discount them entirely unless they were
renames.

Which means that the stat output will simply not show files that only
had "other" changes: they were created or deleted, or their mode was
changed.

Now, those changes do show up in the summary, but so do renames, so
the diffstat logic is inconsistent. Why does it show renames with zero
lines changed, but not mode changes or added files with zero lines
changed?

So change the logic to not check for "is_renamed", but for
"is_interesting" instead, where "interesting" is judged to be any
action but a pure data change (because a pure data change with zero
data changed really isn't worth showing, if we ever get one in our
diffpairs).

So if you did

   chmod +x Makefile
   git diff --stat

before, it would show empty (" 0 files changed"), with this it shows

 Makefile | 0
 1 file changed, 0 insertions(+), 0 deletions(-)

which I think is a more correct diffstat (and then with "--summary" it
shows *what* the metadata change to Makefile was - this is completely
consistent with our handling of renamed files).

Side note: the old behavior was *really* odd. With no changes at all,
"git diff --stat" output was empty. With just a chmod, it said "0
files changed". No way is our legacy behavior sane.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t1400-update-ref: Add test verifying bug with symrefs in delete_ref()

When deleting a ref through a symref (e.g. using 'git update-ref -d HEAD'
to delete refs/heads/master), we currently fail to remove the packed
version of that ref. This testcase demonstrates the bug.

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix failure to delete a packed ref through a symref

When deleting a ref through a symref (e.g. using 'git update-ref -d HEAD'
to delete refs/heads/master), we would remove the loose ref, but a packed
version of the same ref would remain, the end result being that instead of
deleting refs/heads/master we would appear to reset it to its state as of
the last repack.

This patch fixes the issue, by making sure we pass the correct ref name
when invoking repack_without_ref() from within delete_ref().

Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
tcsh-completion re-using git-completion.bash

The current tcsh-completion support for Git, as can be found on the
Internet, takes the approach of defining the possible completions
explicitly.  This has the obvious draw-back to require constant
updating as the Git code base evolves.

The approach taken by this commit is to to re-use the advanced bash
completion script and use its result for tcsh completion.  This is
achieved by sourcing the bash script and outputting the completion
result for tcsh consumption.

Three solutions were looked at to implement this approach with (C)
being retained:

  A) Modifications:
          git-completion.bash and new git-completion.tcsh

     Modify the existing git-completion.bash script to support
     being sourced using bash (as now), but also executed using bash.
     When being executed, the script will output the result of the
     computed completion to be re-used elsewhere (e.g., in tcsh).

     The modification to git-completion.bash is made not to be
     tcsh-specific, but to allow future users to also re-use its
     output.  Therefore, to be general, git-completion.bash accepts a
     second optional parameter, which is not used by tcsh, but could
     prove useful for other users.

     Pros:
       1- allows the git-completion.bash script to easily be re-used
       2- tcsh support is mostly isolated in git-completion.tcsh
     Cons (for tcsh users only):
       1- requires the user to copy both git-completion.tcsh and
          git-completion.bash to ${HOME}
       2- requires bash script to have a fixed name and location:
          ${HOME}/.git-completion.bash

  B) Modifications:
          git-completion.bash

     Modify the existing git-completion.bash script to support
     being sourced using bash (as now), but also executed using bash,
     and sourced using tcsh.

     Pros:
       1- only requires the user to deal with a single file
       2- maintenance more obvious for tcsh since it is entirely part
          of the same git-completion.bash script.
     Cons:
       1- tcsh support could affect bash support as they share the
          same script
       2- small tcsh section must use syntax suitable for both tcsh
          and bash and must be at the beginning of the script
       3- requires script to have a fixed name and location:
          ${HOME}/.git-completion.sh (for tcsh users only)

  C) Modifications:
          New git-completion.tcsh

     Provide a short tcsh script that generates another script
     which extends git-completion.bash.  This new script can be
     used by tcsh to perform completion.

     Pros:
       1- tcsh support is entirely isolated in git-completion.tcsh
       2- new tcsh script can be as complex as needed
     Cons (for tcsh users only):
       1- requires the user to copy both git-completion.tcsh and
          git-completion.bash to ${HOME}
       2- requires bash script to have a fixed name and location:
          ${HOME}/.git-completion.bash
       3- sourcing the new script will generate a third script

Approach (C) was selected avoid any modification to git-completion.bash.

Signed-off-by: Marc Khouzam <marc.khouzam@gmail.com>
Reviewed-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation: move diff.wordRegex from config.txt to diff-config.txt

19299a8 (Documentation: Move diff.<driver>.* from config.txt to
diff-config.txt, 2011-04-07) moved the diff configuration options to
diff-config.txt, but forgot about diff.wordRegex, which was left
behind in config.txt.  Fix this.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff: introduce diff.submodule configuration variable

Introduce a diff.submodule configuration variable corresponding to the
'--submodule' command-line option of 'git diff'.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff: rename "set" variable

Once upon a time the builtin_diff function used one color, and the color
variables were called "set" and "reset". Nowadays it is a much longer
function and we use several colors (e.g., "add", "del"). Rename "set" to
"meta" to show that it is the color for showing diff meta-info (it still
does not indicate that it is a "color", but at least it matches the
scheme of the other color variables).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
submodule: display summary header in bold

Currently, 'git diff --submodule' displays output with a bold diff
header for non-submodules.  So this part is in bold:

    diff --git a/file1 b/file1
    index 30b2f6c..2638038 100644
    --- a/file1
    +++ b/file1

For submodules, the header looks like this:

    Submodule submodule1 012b072..248d0fd:

Unfortunately, it's easy to miss in the output because it's not bold.
Change this.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
USE CGYWIN_V15_WIN32API as macro to select api for cygwin

The previous macro was confusing to some, and did not include "cygwin" in
its name. The updated name more clearly expresses a choice of the
win32api implementation that shipped with version 1.5 of cygwin.

Signed-off-by: Mark Levedahl <mlevedahl@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'ml/cygwin-mingw-headers' into next

Finishing touch to rename a confusingly named preprocessor macro.

Will merge to 'master' in the sixth batch.

* ml/cygwin-mingw-headers:
  USE CGYWIN_V15_WIN32API as macro to select api for cygwin
Merge branch 'jh/update-ref-d-through-symref' into next

"update-ref -d --deref SYM" to delete a ref through a symbolic ref
that points to it did not remove it correctly.

* jh/update-ref-d-through-symref:
  Fix failure to delete a packed ref through a symref
  t1400-update-ref: Add test verifying bug with symrefs in delete_ref()
Merge branch 'rr/submodule-diff-config' into next

Lets "git diff --submodule=log" become the default via configuration.

* rr/submodule-diff-config:
  submodule: display summary header in bold
  diff: rename "set" variable
  diff: introduce diff.submodule configuration variable
  Documentation: move diff.wordRegex from config.txt to diff-config.txt
Merge branch 'mk/complete-tcsh' into next

* mk/complete-tcsh:
  tcsh-completion re-using git-completion.bash
Merge branch 'lt/diff-stat-show-0-lines' into next

We failed to mention a file without any content change but whose
permission bit was modified, or (worse yet) a new file without any
content in the "git diff --stat" output.

Still needs some test updates.

* lt/diff-stat-show-0-lines:
  Fix "git diff --stat" for interesting - but empty - file changes