filter-branch: do not forget the '@' prefix to force git-timestamp

For some reason, this script reinvents, instead of refactoring the
existing one in git-sh-setup, the logic to grab ident information
from an existing commit; it was missed when the corresponding logic
in git-sh-setup was updated with 2c733fb (parse_date(): '@' prefix
forces git-timestamp, 2012-02-02).

Teach the script that it is OK to have a way ancient timestamp in
the commits that are being filtered.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
submodules: don't stumble over symbolic links when cloning recursively

Since 69c3051 (submodules: refactor computation of relative gitdir path)
cloning a submodule recursively fails for nested submodules when a
symbolic link is part of the path to the work tree of the superproject.

This happens when module_clone() tries to find the relative paths between
the work tree and the git dir. When a symbolic link in current $PWD points
to a directory that is at a different level, then determining the number
of "../" needed to traverse to the superproject's work tree leads to a
wrong result.

As there is no portable way to say "pwd -P", use cd_to_toplevel to remove
the link from $PWD, which fixes this problem.

A test for this issue has been added to t7406.

Reported-by: Bob Halley <halley@play-bow.org>
Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
date.c: Fix off by one error in object-header date parsing

It is perfectly OK for a valid decimal integer to begin with '9' but
116eb3a (parse_date(): allow ancient git-timestamp, 2012-02-02) did
not express the range correctly.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
t7003: add test to filter a branch with a commit at epoch

Running filter-branch on a history that has a commit with timestamp
at epoch used to fail, but it should have been fixed.  Add test to
make sure it won't break again.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
am: indicate where a failed patch is to be found

If "git am" fails to apply something, the end user may need to know
where to find the patch that failed to apply, so that the user can
do other things (e.g. trying "GNU patch" on it, running "diffstat"
to see what it tried to change, etc.)  The input to "am" may have
contained more than one patch, or the message may have been MIME
encoded, and knowing what the user fed to "am" does not help very
much for this purpose.

Also introduce advice.amworkdir configuration to allow people who
learned where to look to squelch this message.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
commit-tree: resurrect command line parsing updates

79a9312 (commit-tree: update the command line parsing, 2011-11-09)
updated the command line parser to understand the usual "flags first
and then non-flag arguments" order, in addition to the original and
a bit unusual "tree comes first and then zero or more -p <parent>".

Unfortunately, ba3c69a (commit: teach --gpg-sign option, 2011-10-05)
broke it by mistake.  Resurrect it, and protect the feature with a
test from future breakages.

Noticed by Keshav Kini
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'kk/maint-1.7.9-commit-tree' into kk/maint-commit-tree

* kk/maint-1.7.9-commit-tree:
  commit-tree: resurrect command line parsing updates
Revert "git-commit-tree(1): update synopsis"

This reverts commit d28436736a078a429213003a9472e8caeb86c286, which
was done without realizing that the updated command line argument
order was lost by mistake.
diff: correctly disable external_diff with --no-ext-diff

Upon seeing a type-change filepair, "diff --no-ext-diff" does not
show the usual "deletion followed by addition" split patch and does
not run the external diff driver either.

This is because the logic to disable external diff was placed at a
wrong level in the callchain.  run_diff_cmd() decides to show the
split patch only when external diff driver is not configured or
specified via GIT_EXTERNAL_DIFF environment, but this is done before
checking if --no-ext-diff was given.  To make things worse,
run_diff_cmd() checks --no-ext-diff and disables the output for such
a filepair completely, as the callchain below it (e.g. builtin_diff)
does not want to handle typechange filepairs.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff: test precedence of external diff drivers

There are three ways to specify an external diff command:
GIT_EXTERNAL_DIFF in the environment, diff.external in the
config, or a "diff" gitattribute. The current order of
precedence is:

  1. gitattribute

  2. GIT_EXTERNAL_DIFF

  3. diff.external

Usually our rule is that environment variables should take
precedence over on-disk config (i.e., option 2 should come
before option 1). However, this situation is trickier than
some, because option 1 is more specific to the individual
file than option 2 (which affects all files), so it might be
preferable. So the current behavior can be seen as
implementing "do the specific thing if we can, but fall back
to this general thing".

This is probably not what we would do if we were writing git
from scratch, but it has been this way for several years,
and is not worth changing. So let's at least document that
this is the way it's supposed to work with a test.

While we're there, let's also make sure that diff.external
(which was not previously tested at all) works by running it
through the same tests as GIT_EXTERNAL_DIFF.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
advice: pass varargs to strbuf_vaddf, not strbuf_addf

The advise() function takes a variable number of arguments
and converts them into a va_list object to pass to strbuf
for handling. However, we accidentally called strbuf_addf
(that takes a variable number of arguments) instead of
strbuf_vaddf (that takes a va_list).

This bug dates back to v1.7.8.1-1-g23cb5bf, but we never
noticed because none of the current callers passes a string
with a format specifier in it. And the compiler did not
notice because the format string is not available at
compile time.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
commit: document the temporary commit message file

We do not document COMMIT_EDITMSG at all, but users may want
to know about it for two reasons:

  1. They may want to tell their editor to configure itself
     for formatting a commit message.

  2. If a commit is aborted by an error, the user may want
     to recover the commit message they typed.

Let's put a note in git-commit(1).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'jc/maint-filter-branch-epoch-date' into maint

In 1.7.9 era, we taught "git rebase" about the raw timestamp format
but we did not teach the same trick to "filter-branch", which rolled
a similar logic on its own.

* jc/maint-filter-branch-epoch-date:
  t7003: add test to filter a branch with a commit at epoch
  date.c: Fix off by one error in object-header date parsing
  filter-branch: do not forget the '@' prefix to force git-timestamp
Merge branch 'jl/maint-1.7.10-recurse-submodules-with-symlink' into maint

When "git submodule add" clones a submodule repository, it can get
confused where to store the resulting submodule repository in the
superproject's .git/ directory when there is a symbolic link in the
path to the current directory.

* jl/maint-1.7.10-recurse-submodules-with-symlink:
  submodules: don't stumble over symbolic links when cloning recursively
Merge branch 'pg/maint-1.7.9-am-where-is-patch' into maint

When "git am" failed, old timers knew to check .git/rebase-apply/patch
to see what went wrong, but we never told the users about it.

* pg/maint-1.7.9-am-where-is-patch:
  am: indicate where a failed patch is to be found
Merge branch 'jv/maint-no-ext-diff' into maint

"git diff --no-ext-diff" did not output anything for a typechange
filepair when GIT_EXTERNAL_DIFF is in effect.

* jv/maint-no-ext-diff:
  diff: test precedence of external diff drivers
  diff: correctly disable external_diff with --no-ext-diff
Merge branch 'kk/maint-commit-tree' into maint

"git commit-tree" learned a more natural "-p <parent> <tree>" order
of arguments long time ago, but recently forgot it by mistake.

* kk/maint-commit-tree:
  Revert "git-commit-tree(1): update synopsis"
  commit-tree: resurrect command line parsing updates
Merge branch 'jk/maint-advise-vaddf' into maint

The advise() function did not use varargs correctly to format
its message.

* jk/maint-advise-vaddf:
  advice: pass varargs to strbuf_vaddf, not strbuf_addf
Merge branch 'jk/maint-commit-document-editmsg' into maint

"$GIT_DIR/COMMIT_EDITMSG" file that is used to hold the commit log
message user edits was not documented.

* jk/maint-commit-document-editmsg:
  commit: document the temporary commit message file
Git 1.7.11.4

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