difftool: parse options using Getopt::Long

Replace custom option/argument parser with standard Getopt::Long
module.  This shortens the code and makes it easier to understand.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: add '--no-gui' option

This commit teaches difftool to handle the '--no-gui' option. This option
negates the existing '--gui' option. The last setting given on the command
line wins.

This allows a user to configure "[alias] mdt = difftool --gui", but still
have the ability to override the setting without error:

$ git mdt --no-gui

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: exit(0) when usage is printed

Prior to this commit, the script exited with an error whenever the
usage string was printed, regardless of the reason it was done. In
cases where usage was printed due to a user request (e.g. '-h'
option), the script should exit without error (exit 0).

This commit adds an argument to the usage function that allows the
exit code to be specified when the function is called.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: remove explicit change of PATH

Adding the script directory to PATH is not needed. The script is
located at '$(git --exec-path)', which is already on the PATH.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: stop appending '.exe' to git

The system call to Git works the same whether or not ".exe" is
appended to "git". The extra code is not necessary.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: eliminate setup_environment function

Removing this function shortens the code and makes it easier to read.
Now all environment variables are set as part of procedural operation.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: teach difftool to handle directory diffs

When 'difftool' is called to compare a range of commits that modify
more than one file, it opens a separate instance of the diff tool for
each file that changed.

The new '--dir-diff' option copies all the modified files to a temporary
location and runs a directory diff on them in a single instance of the
diff tool.

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: print list of valid tools with '--tool-help'

Since bc7a96a (mergetool--lib: Refactor tools into separate files,
2011-08-18), it is possible to add a new diff tool by creating a simple
script in the '$(git --exec-path)/mergetools' directory.  Updating the
difftool help text is still a manual process, and the documentation can
easily go out of sync.

This commit teaches difftool the '--tool-help' option, which:
  - Reads the list of valid tools from 'mergetools/*'
  - Determines which of them are actually installed
  - Determines which are capable of diffing (i.e. not just a merge tool)
  - Prints the resulting list for the user

Signed-off-by: Tim Henigan <tim.henigan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
log-tree: use custom line terminator in line termination mode

When using a custom format in line termination mode (as opposed to line
separation mode), the configured line terminator is not used, so things
like "git log --pretty=tformat:%H -z" do not work properly.

Make it use the line terminator the user ordered.

Signed-off-by: Jan Krüger <jk@jk.gs>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
log-tree: the previous one is still not quite right

The correct output would have NUL after each commit, so "-z --format=%s"
would have a single-liner subject with the line-terminating LF replaced
with NUL, and "-p/--stat -z --format=%s" would have a single-liner subject
with its line-terminating LF, followed by the diff/diffstat in which the
terminating LF of the last line is replaced with NUL, but to be consistent
with what "-p/--stat -z --pretty=format:%s" does, I think it is OK to
append NUL to the diff/diffstat part instead of replacing its last LF with
NUL.

The added test shows the update is still not right for "-p -z --format".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
test: modernize style of t4006

Signed-off-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
tests: check --[short]stat output after chmod

Add a test to check 'diff --stat' output with a text file after chmod,
and the same for a binary file. This demonstrates that text and binary
files are treated differently, which can be misleading.

While at it, add tests to check --shortstat output, too.

Reported-by: Martin Mareš <mj@ucw.cz>
Signed-off-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --stat: report mode-only changes for binary files like text files

Mode-only changes to binary files without content change were reported as
if they were rewritten, but text files in the same situation were reported
as "unchanged". Let's treat binary files like text files here, and simply
say that they are unchanged.

Output of --shortstat is modified in the same way.

Reported-by: Martin Mareš <mj@ucw.cz>
Signed-off-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --stat: do not run diff on indentical files

If two objects are known to be equal, there is no point running the diff.

Signed-off-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t4006: Windows do not have /dev/zero

We only need to have a file with _some_ binary contents; be nice to
our Windows friends and avoid using /dev/zero

Signed-off-by: Johannes Sixt <j.sixt@viscovery.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git cherry-pick: do not dereference a potential NULL pointer

In the case the pointer could be NULL, the function that gave the caller
the NULL pointer would already have issued an error message, so simply
returning early with an error status without issuing a new message is
sufficient.  The same for parse_commit() that will show necessary error
message when the argument is not NULL, and will return error silently
when the argument is NULL.

Noticed-by: Michael Mueller
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git p4 doc: fix formatting

Attach example sections to previous level of indenting.

Fix a trailing ::

Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'cb/maint-report-mount-point-correctly-in-setup' into maint

The filesystem boundary was not correctly reported when .git directory
discovery stopped at a mount point.

By Clemens Buchacher
* cb/maint-report-mount-point-correctly-in-setup:
  properly keep track of current working directory
Merge branch 'rt/cherry-revert-conflict-summary' into maint

In the older days, the header "Conflicts:" in "cherry-pick" and "merge"
was separated by a blank line from the list of paths that follow for
readability, but when "merge" was rewritten in C, we lost it by
mistake. Remove the newline from "cherry-pick" to make them match again.

By Ralf Thielow
* rt/cherry-revert-conflict-summary:
  sequencer: remove additional blank line
Merge branch 'pw/t5800-import-race-fix' into maint

The test scaffolding for fast-import was flaky.

By Pete Wyckoff
* pw/t5800-import-race-fix:
  git-remote-testgit: fix race when spawning fast-import