git-show: fix 'git show -s' to not add extra terminator after merge commit

When git show -s is called for merge commit it prints extra newline
after any merge commit. This differs from output for commits with one
parent. Fix it by more thorough checking that diff output is disabled.

The code in question exists since commit 3969cf7db1. The additional
newline is really needed for cases when patch is requested, test
t4013-diff-various.sh contains cases which can demonstrate behavior when
the condition is restricted further.

Tests:

Added merge commit to 'set up a bit of history' case in t7007-show.sh to
cover the fix.

Existing tests are updated to demonstrate the new behaviour.  Earlier,
the tests that used "git show -s --pretty=format:%s", even though
"--pretty=format:%s" calls for item separator semantics and does not ask
for the terminating newline after the last item, expected the output to
end with such a newline.  They were relying on the buggy behaviour.  Use
of "--format=%s", which is equivalent to "--pretty=tformat:%s" that asks
for a terminating newline after each item, is a more realistic way to
use the command.

In the test 'merge log messages' the expected data is changed, because
it was explicitly listing the extra newline. Also the msg.nologff and
msg.nolognoff expected files are replaced by one msg.nolog, because they
were diffing because of the bug, and now there should be no difference.

Signed-off-by: Max Kirillov <max@max630.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
run_diff_files: do not look at uninitialized stat data

If we try to diff an index entry marked CE_VALID (because it
was marked with --assume-unchanged), we do not bother even
running stat() on the file to see if it was removed. This
started long ago with 540e694 (Prevent diff machinery from
examining assume-unchanged entries on worktree, 2009-08-11).

However, the subsequent code may look at our "struct stat"
and expect to find actual data; currently it will find
whatever cruft was left on the stack. This can cause
problems in two situations:

  1. We call match_stat_with_submodule with the stat data,
     so a submodule may be erroneously marked as changed.

  2. If --find-copies-harder is in effect, we pass all
     entries, even unchanged ones, to diff_change, so it can
     list them as rename/copy sources. Since we found no
     change, we assume that function will realize it and not
     actually display any diff output. However, we end up
     feeding it a bogus mode, leading it to sometimes claim
     there was a mode change.

We can fix both by splitting the CE_VALID and regular code
paths, and making sure only to look at the stat information
in the latter. Furthermore, we push the declaration of our
"struct stat" down into the code paths that actually set it,
so we cannot accidentally access it uninitialized in future
code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'mk/show-s-no-extra-blank-line-for-merges' into jch

* mk/show-s-no-extra-blank-line-for-merges:
  git-show: fix 'git show -s' to not add extra terminator after merge commit

# Conflicts:
# 	combine-diff.c
Merge branch 'sk/wincred' into jch

* sk/wincred:
  wincred: avoid overwriting configured variables
  wincred: add install target
Merge branch 'jl/vcompare-makes-2.0-satisify-1.7-or-later' into jch

* jl/vcompare-makes-2.0-satisify-1.7-or-later:
  git-gui: use vcompare when comparing the git version
Merge branch 'jk/diff-files-assume-unchanged' into jch

* jk/diff-files-assume-unchanged:
  run_diff_files: do not look at uninitialized stat data
run-command: store an optional argv_array

All child_process structs need to point to an argv. For
flexibility, we do not mandate the use of a dynamic
argv_array. However, because the child_process does not own
the memory, this can make memory management with a
separate argv_array difficult.

For example, if a function calls start_command but not
finish_command, the argv memory must persist. The code needs
to arrange to clean up the argv_array separately after
finish_command runs. As a result, some of our code in this
situation just leaks the memory.

To help such cases, this patch adds a built-in argv_array to
the child_process, which gets cleaned up automatically (both
in finish_command and when start_command fails).  Callers
may use it if they choose, but can continue to use the raw
argv if they wish.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
run_column_filter: use argv_array

We currently set up the argv array by hand in a fixed-size
stack-local array. Using an argv array is more readable, as
it handles buffer allocation us (not to mention makes it
obvious we do not overflow the array).

However, there's a more subtle benefit, too. We leave the
function having run start_command (with the child_process
in a static global), and then later run finish_command from
another function. That means when we run finish_command,
neither column_process.argv nor the memory it points to is
valid any longer.

Most of the time finish_command does not bother looking at
argv, but it may if it encounters an error (e.g., waitpid
failure or signal death). This is unusual, which is why
nobody has noticed. But by using run-command's built-in
argv_array, the memory ownership is handled for us
automatically.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git_connect: use argv_array

This avoids magic numbers when we allocate fixed-size argv
arrays, and makes it more obvious that we are not
overflowing.

It is also the first step to fixing a memory leak. When
git_connect returns a child_process struct, the argv array
in the struct is dynamically allocated, but the individual
strings are not (they are either owned elsewhere, or are
freed). Later, in finish_connect, we free the array but
leave the strings alone.

This works for the child_process created by git_connect, but
if we use transport_take_over, we may also end up with a
child_process created by transport-helper's get_helper.
In that case, the strings are freshly allocated, and we
would want to free them.  However, we have no idea in
finish_connect which type we have.

By consistently using run-command's internal argv-array, we
do not have to worry about this issue at all; finish_command
takes care of it for us, and we can drop our manual free
entirely.

Note that this actually makes the get_helper leak slightly
worse; now we are leaking both the strings and the array.
But when we adjust it in a future patch, that leak will go
away entirely.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
get_helper: use run-command's internal argv_array

The get_helper functions dynamically allocates an
argv_array, feeds it to start_command, and then returns. We
then have to later clean up the memory manually after
calling finish_command. We can make this simpler by just
using run-command's internal argv_array, which handles
cleanup for us.

This also prevents a memory leak in the case that
transport_take_over is used, in which case we free the child
in finish_connect, which does not manually free the array.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
get_exporter: use argv_array

This simplifies the code and avoids a fixed array size that
we might accidentally overflow. It also prevents a leak
after finish_command is run, by using the argv_array that
run-command manages for us.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
get_importer: use run-command's internal argv_array

This saves a few lines and lets us avoid having to clean up
the memory manually when the command finishes.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
argv-array: drop "detach" code

The argv_array_detach function (and associated free() function) was
really only useful for transferring ownership of the memory to a "struct
child_process". Now that we have an internal argv_array in that struct,
there are no callers left.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'jk/argv-array-for-child-process' into jch

* jk/argv-array-for-child-process:
  argv-array: drop "detach" code
  get_importer: use run-command's internal argv_array
  get_exporter: use argv_array
  get_helper: use run-command's internal argv_array
  git_connect: use argv_array
  run_column_filter: use argv_array
  run-command: store an optional argv_array
open_sha1_file: report "most interesting" errno

When we try to open a loose object file, we first attempt to
open in the local object database, and then try any
alternates. This means that the errno value when we return
will be from the last place we looked (and due to the way
the code is structured, simply ENOENT if we do not have have
any alternates).

This can cause confusing error messages, as read_sha1_file
checks for ENOENT when reporting a missing object. If errno
is something else, we report that. If it is ENOENT, but
has_loose_object reports that we have it, then we claim the
object is corrupted. For example:

    $ chmod 0 .git/objects/??/*
    $ git rev-list --all
    fatal: loose object b2d6fab18b92d49eac46dc3c5a0bcafabda20131 (stored in .git/objects/b2/d6fab18b92d49eac46dc3c5a0bcafabda20131) is corrupt

This patch instead keeps track of the "most interesting"
errno we receive during our search. We consider ENOENT to be
the least interesting of all, and otherwise report the first
error found (so problems in the object database take
precedence over ones in alternates). Here it is with this
patch:

    $ git rev-list --all
    fatal: failed to read object b2d6fab18b92d49eac46dc3c5a0bcafabda20131: Permission denied

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'jk/report-fail-to-read-objects-better' into jch

* jk/report-fail-to-read-objects-better:
  open_sha1_file: report "most interesting" errno
git grep -O -i: if the pager is 'less', pass the '-I' option

When <command> happens to be the magic string "less", today

	git grep -O<command> -e<pattern>

helpfully passes +/<pattern> to less so you can navigate through
the results within a file using the n and shift+n keystrokes.

Alas, that doesn't do the right thing for a case-insensitive match,
i.e.

	git grep -i -O<command> -e<pattern>

For that case we should pass --IGNORE-CASE to "less" so that n and
shift+n can move between results ignoring case in the pattern.

The original patch came from msysgit and used "-i", but that was not
due to lack of support for "-I" but it merely overlooked that it
ought to work even when the pattern contains capital letters.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Stepan Kasal <kasal@ucw.cz>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'sk/spawn-less-case-insensitively-from-grep-O-i' into jch

* sk/spawn-less-case-insensitively-from-grep-O-i:
  git grep -O -i: if the pager is 'less', pass the '-I' option
Revert "Merge branch 'fc/transport-helper-sync-error-fix'"

This reverts commit d508e4a8e2391ae2596403b6478d01cf3d5f928f,
reversing changes made to e42552135a2a396f37053a89f44952ea907870b2.

The author of the original topic says he broke the upcoming 2.0
release with something that relates to "synchronization crash
regression" while refusing to give further specifics, so this would
unfortunately be the safest option for the upcoming release.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-helpers: point at their upstream repositories

Signed-off-by: Junio C Hamano <gitster@pobox.com>