format_commit_message(): simplify calls to logmsg_reencode()

All the other callers of logmsg_reencode() pass return value of
get_commit_output_encoding() or get_log_output_encoding().  Teach
the function to optionally take NULL as a synonym to "" aka "no
conversion requested" so that we can simplify the only remaining
calling site.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
fetch: ignore wildcarded refspecs that update local symbolic refs

In a repository cloned from somewhere else, you typically have a
symbolic ref refs/remotes/origin/HEAD pointing at the 'master'
remote-tracking ref that is next to it.  When fetching into such a
repository with "git fetch --mirror" from another repository that
was similarly cloned, the implied wildcard refspec refs/*:refs/*
will end up asking to update refs/remotes/origin/HEAD with the
object at refs/remotes/origin/HEAD at the remote side, while asking
to update refs/remotes/origin/master the same way.  Depending on the
order the two updates happen, the latter one would find that the
value of the ref before it is updated has changed from what the code
expects.

When the user asks to update the underlying ref via the symbolic ref
explicitly without using a wildcard refspec, e.g. "git fetch $there
refs/heads/master:refs/remotes/origin/HEAD", we should still let him
do so, but when expanding wildcard refs, it will result in a more
intuitive outcome if we simply ignore local symbolic refs.

As the purpose of the symbolic ref refs/remotes/origin/HEAD is to
follow the ref it points at (e.g. refs/remotes/origin/master), its
value would change when the underlying ref is updated.

Earlier commit da3efdb (receive-pack: detect aliased updates which
can occur with symrefs, 2010-04-19) fixed a similar issue for "git
push".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
submodule: add get_submodule_config helper funtion

Several submodule configuration variables
(e.g. fetchRecurseSubmodules) are read from .gitmodules with local
overrides from the usual git config files.  This shell function mimics
that logic to help initialize configuration variables in
git-submodule.sh.

Signed-off-by: W. Trevor King <wking@tremily.us>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mailmap: refactor mailmap parsing for non-file sources

The read_single_mailmap function opens a mailmap file and
parses each line. In preparation for having non-file
mailmaps, let's pull out the line-parsing logic into its own
function (read_mailmap_line), and rename the file-parsing
function to match (read_mailmap_file).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mailmap: support reading mailmap from blobs

In a bare repository, there isn't a simple way to respect an
in-tree mailmap without extracting it to a temporary file.
This patch provides a config variable, similar to
mailmap.file, which reads the mailmap from a blob in the
repository.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mailmap: clean up read_mailmap error handling

The error handling for the read_mailmap function is odd. It
returns 1 on error, rather than -1. And it treats a
non-existent mailmap as an error, even though there is no
reason that one needs to exist. Unless some other mailmap
source loads successfully, in which case the original error
is completely masked.

This does not cause any bugs, however, because no caller
bothers to check the return value, anyway. Let's make this a
little more robust to real errors and less surprising for
future callers that do check the error code:

  1. Return -1 on errors.

  2. Treat a missing entry (e.g., no mailmap.file given),
     ENOENT, or a non-existent blob (for mailmap.blob) as
     "no error".

  3. Complain loudly when a real error (e.g., a transient
     I/O error, no permission to open the mailmap file,
     missing or corrupted blob object, etc) occurs.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mailmap: fix some documentation loose-ends for mailmap.blob

Anywhere we mention mailmap.file, it is probably worth
mentioning mailmap.blob, as well.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
mailmap: default mailmap.blob in bare repositories

The motivation for mailmap.blob is to let users of bare
repositories use the mailmap feature, as they would not have
a checkout containing the .mailmap file. We can make it even
easier for them by just looking in HEAD:.mailmap by default.

We can't know for sure that this is where they would keep a
mailmap, of course, but it is the best guess (and it matches
the non-bare behavior, which reads from HEAD:.mailmap in the
working tree). If it's missing, git will silently ignore the
setting.

We do not do the same magic in the non-bare case, because:

  1. In the common case, HEAD:.mailmap will be the same as
     the .mailmap in the working tree, which is a no-op.

  2. In the uncommon case, the user has modified .mailmap
     but not yet committed it, and would expect the working
     tree version to take precedence.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Support builds when sys/param.h is missing

An option is added to the Makefile to skip the inclusion of sys/param.h.
The only known platform with this condition thus far is the z/OS UNIX System
Services environment.

Signed-off-by: David Michael <fedora.dm0@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Detect when the passwd struct is missing pw_gecos

NO_GECOS_IN_PWENT was documented with other Makefile variables but was only
enforced by manually defining it to the C preprocessor.  This adds support
for detecting the condition with configure and defining the make variable.

Signed-off-by: David Michael <fedora.dm0@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Generalize the inclusion of strings.h

The header strings.h was formerly only included for HP NonStop (aka
Tandem) to define strcasecmp, but another platform requiring this
inclusion has been found.  The build system will now include the
file based on its presence determined by configure.

Signed-off-by: David Michael <fedora.dm0@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
make error()'s constant return value more visible

When git is compiled with "gcc -Wuninitialized -O3", some
inlined calls provide an additional opportunity for the
compiler to do static analysis on variable initialization.
For example, with two functions like this:

  int get_foo(int *foo)
  {
	if (something_that_might_fail() < 0)
		return error("unable to get foo");
	*foo = 0;
	return 0;
  }

  void some_fun(void)
  {
	  int foo;
	  if (get_foo(&foo) < 0)
		  return -1;
	  printf("foo is %d\n", foo);
  }

If get_foo() is not inlined, then when compiling some_fun,
gcc sees only that a pointer to the local variable is
passed, and must assume that it is an out parameter that
is initialized after get_foo returns.

However, when get_foo() is inlined, the compiler may look at
all of the code together and see that some code paths in
get_foo() do not initialize the variable. As a result, it
prints a warning. But what the compiler can't see is that
error() always returns -1, and therefore we know that either
we return early from some_fun, or foo ends up initialized,
and the code is safe.  The warning is a false positive.

If we can make the compiler aware that error() will always
return -1, it can do a better job of analysis. The simplest
method would be to inline the error() function. However,
this doesn't work, because gcc will not inline a variadc
function. We can work around this by defining a macro. This
relies on two gcc extensions:

  1. Variadic macros (these are present in C99, but we do
     not rely on that).

  2. Gcc treats the "##" paste operator specially between a
     comma and __VA_ARGS__, which lets our variadic macro
     work even if no format parameters are passed to
     error().

Since we are using these extra features, we hide the macro
behind an #ifdef. This is OK, though, because our goal was
just to help gcc.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
silence some -Wuninitialized false positives

There are a few error functions that simply wrap error() and
provide a standardized message text. Like error(), they
always return -1; knowing that can help the compiler silence
some false positive -Wuninitialized warnings.

One strategy would be to just declare these as inline in the
header file so that the compiler can see that they always
return -1. However, gcc does not always inline them (e.g.,
it will not inline opterror, even with -O3), which renders
our change pointless.

Instead, let's follow the same route we did with error() in
the last patch, and define a macro that makes the constant
return value obvious to the compiler.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
completion: complete refs for "git commit -c"

The "-c" and "-C" options take an existing commit, so let's
complete refs, just as we would for --squash or --fixup.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cache-tree: remove dead i-t-a code in verify_cache()

This code is added in 331fcb5 (git add --intent-to-add: do not let an
empty blob be committed by accident - 2008-11-28) to forbid committing
when i-t-a entries are present. When we allow that, we forgot to
remove this.

Noticed-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cache-tree: replace "for" loops in update_one with "while" loops

The loops in update_one can be increased in two different ways: step
by one for files and by <n> for directories. "for" loop is not
suitable for this as it always steps by one and special handling is
required for directories. Replace them with "while" loops for clarity.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cache-tree: fix writing cache-tree when CE_REMOVE is present

entry_count is used in update_one() for two purposes:

1. to skip through the number of processed entries in in-memory index
2. to record the number of entries this cache-tree covers on disk

Unfortunately when CE_REMOVE is present these numbers are not the same
because CE_REMOVE entries are automatically removed before writing to
disk but entry_count is not adjusted and still counts CE_REMOVE
entries.

Separate the two use cases into two different variables. #1 is taken
care by the new field count in struct cache_tree_sub and entry_count
is prepared for #2.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cache-tree: invalidate i-t-a paths after generating trees

Intent-to-add entries used to forbid writing trees so it was not a
problem. After commit 3f6d56d (commit: ignore intent-to-add entries
instead of refusing - 2012-02-07), we can generate trees from an index
with i-t-a entries.

However, the commit forgets to invalidate all paths leading to i-t-a
entries. With fully valid cache-tree (e.g. after commit or
write-tree), diff operations may prefer cache-tree to index and not
see i-t-a entries in the index, because cache-tree does not have them.

Reported-by: Jonathon Mah <me@JonathonMah.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
tests: test number comes first in 'not ok $count - $message'

The old output to say "not ok - 1 messsage" was working by accident
only because the test numbers are optional in TAP.

Signed-off-by: Adam Spiers <git@adamspiers.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t6006: clean up whitespace

The test_format function did not indent its in-line test
script in an attempt to make the output of the test look
better. But it does not make a big difference to the output,
and the source looks quite ugly. Let's use our normal
indenting instead.

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