mergetools/vim: remove redundant diff command

vimdiff and vimdiff2 differ only by their merge command so remove the
logic in the diff command since it's not actually needed.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mergetool--lib: improve show_tool_help() output

Check the can_diff and can_merge functions before deciding whether
to add the tool to the available/unavailable lists.  This makes
"--tool-help" context-sensitive so that "git mergetool --tool-help"
displays merge tools only and "git difftool --tool-help" displays
diff tools only.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mergetool--lib: don't call "exit" in setup_tool

This will make it easier to use setup_tool in places where we expect
that the selected tool will not support the current mode.

We need to introduce a new return code for setup_tool to differentiate
between the case of "the selected tool is invalid" and "the selected
tool is not a built-in" since we must call setup_tool when a custom
'merge.<tool>.path' is configured for a built-in tool but avoid failing
when the configured tool is not a built-in.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mergetools: simplify how we handle "vim" and "defaults"

Remove the exceptions for "vim" and "defaults" in the mergetool library
so that every filename in mergetools/ matches 1:1 with the name of a
valid built-in tool.

Define the trivial fallback definition of shell functions in-line in
git-mergetool-lib script, instead of dot-sourcing them from another
file.  The result is much easier to follow.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mergetool--lib: simplify command expressions

Update variable assignments to always use $(command "$arg")
in their RHS instead of "$(command "$arg")" as the latter
is harder to read.  Make get_merge_tool_cmd() simpler by
avoiding "echo" and $(command) substitutions completely.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mergetool--lib: improve the help text in guess_merge_tool()

This code path is only activated when the user does not have a valid
configured tool.  Add a message to guide new users towards configuring a
default tool.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mergetool--lib: add functions for finding available tools

Refactor show_tool_help() so that the tool-finding logic is broken out
into a separate show_tool_names() function.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
doc: generate a list of valid merge tools

Use the show_tool_names() function to build lists of all
the built-in tools supported by difftool and mergetool.
This frees us from needing to update the documentation
whenever a new tool is added.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
branch: no detached HEAD check when editing another branch's description

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
branch: reject -D/-d without branch name

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
branch: give a more helpful message on redundant arguments

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
branch: mark more strings for translation

Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
sequencer.c: rework search for start of footer to improve clarity

This code sequence is somewhat difficult to read.  Let's rewrite it
using more descriptive variable names to try to make it easier to
understand.

Signed-off-by: Brandon Casey <drafnel@gmail.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
commit, cherry-pick -s: remove broken support for multiline rfc2822 fields

Starting with c1e01b0c (commit: More generous accepting of RFC-2822 footer
lines, 2009-10-28), "git commit -s" carefully parses the last paragraph of
each commit message to check if it consists only of RFC2822-style headers,
in which case the signoff will be added as a new line in the same list:

   Reported-by: Reporter <reporter@example.com>
   Signed-off-by: Author <author@example.com>
   Acked-by: Lieutenant <lt@example.com>

It even included support for accepting indented continuation lines for
multiline fields.  Unfortunately the multiline field support is broken
because it checks whether buf[k] (the first character of the *next* line)
instead of buf[i] is a whitespace character.  The result is that any footer
with a continuation line is not accepted, since the last continuation line
neither starts with an RFC2822 field name nor is followed by a continuation
line.

That this has remained broken for so long is good evidence that nobody
actually needed multiline fields.  Rip out the broken continuation support.

There should be no functional change.

[Thanks to Jonathan Nieder for the excellent commit message]

Signed-off-by: Brandon Casey <bcasey@nvidia.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t/test-lib-functions.sh: allow to specify the tag name to test_commit

The <message> part of test_commit() may not be appropriate for a tag name.
So let's allow test_commit to accept a fourth argument to specify the tag
name.

Signed-off-by: Brandon Casey <bcasey@nvidia.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t/t3511: add some tests of 'cherry-pick -s' functionality

Add some tests to ensure that 'cherry-pick -s' operates in the following
manner:

   * Inserts a blank line before appending a s-o-b to a commit message that
     does not contain a s-o-b footer

   * Does not mistake first line "subject: description" as a s-o-b footer

   * Does not mistake single word message body as conforming to rfc2822

   * Appends a s-o-b when last s-o-b in footer does not match committer
     s-o-b, even when committer's s-o-b exists elsewhere in footer.

   * Does not append a s-o-b when last s-o-b matches committer s-o-b

   * Correctly detects a non-conforming footer containing a mix of s-o-b
     like elements and s-o-b elements. (marked "expect failure")

Signed-off-by: Brandon Casey <bcasey@nvidia.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
sequencer.c: recognize "(cherry picked from ..." as part of s-o-b footer

When 'cherry-pick -s' is used to append a signed-off-by line to a cherry
picked commit, it does not currently detect the "(cherry picked from..."
that may have been appended by a previous 'cherry-pick -x' as part of the
s-o-b footer and it will insert a blank line before appending a new s-o-b.

Let's detect "(cherry picked from...)" as part of the footer so that we
will produce this:

   Signed-off-by: A U Thor <author@example.com>
   (cherry picked from da39a3ee5e6b4b0d3255bfef95601890afd80709)
   Signed-off-by: C O Mmitter <committer@example.com>

instead of this:

   Signed-off-by: A U Thor <author@example.com>
   (cherry picked from da39a3ee5e6b4b0d3255bfef95601890afd80709)

   Signed-off-by: C O Mmitter <committer@example.com>

Signed-off-by: Brandon Casey <bcasey@nvidia.com>
Acked-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
sequencer.c: always separate "(cherry picked from" from commit body

Start treating the "(cherry picked from" line added by cherry-pick -x
the same way that the s-o-b lines are treated.  Namely, separate them
from the main commit message body with an empty line.

This commit is mostly a code movement, but notice that
has_conforming_footer() was modified, in addition to being moved.

Introduce tests to test this functionality.

Signed-off-by: Brandon Casey <bcasey@nvidia.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
sequencer.c: teach append_signoff how to detect duplicate s-o-b

Teach append_signoff how to detect a duplicate s-o-b in the commit footer.
This is in preparation to unify the append_signoff implementations in
log-tree.c and sequencer.c.

Fixes test in t3511.

Signed-off-by: Brandon Casey <bcasey@nvidia.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
sequencer.c: teach append_signoff to avoid adding a duplicate newline

Teach append_signoff to detect whether a blank line exists at the position
that the signed-off-by line will be added, and avoid adding an additional
one if one already exists.  This is necessary to allow format-patch to add a
s-o-b to a patch with no commit message without adding an extra newline.  A
following patch will make format-patch use this function rather than the
append_signoff implementation inside log-tree.c.

Signed-off-by: Brandon Casey <bcasey@nvidia.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>