gitk: Avoid Meta1-F5

Meta1-F5 is commonly mapped by window managers and what not.
Use Shift-F5 instead.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff: do not use null sha1 as a sentinel value

The diff code represents paths using the diff_filespec
struct. This struct has a sha1 to represent the sha1 of the
content at that path, as well as a sha1_valid member which
indicates whether its sha1 field is actually useful. If
sha1_valid is not true, then the filespec represents a
working tree file (e.g., for the no-index case, or for when
the index is not up-to-date).

The diff_filespec is only used internally, though. At the
interfaces to the diff subsystem, callers feed the sha1
directly, and we create a diff_filespec from it. It's at
that point that we look at the sha1 and decide whether it is
valid or not; callers may pass the null sha1 as a sentinel
value to indicate that it is not.

We should not typically see the null sha1 coming from any
other source (e.g., in the index itself, or from a tree).
However, a corrupt tree might have a null sha1, which would
cause "diff --patch" to accidentally diff the working tree
version of a file instead of treating it as a blob.

This patch extends the edges of the diff interface to accept
a "sha1_valid" flag whenever we accept a sha1, and to use
that flag when creating a filespec. In some cases, this
means passing the flag through several layers, making the
code change larger than would be desirable.

One alternative would be to simply die() upon seeing
corrupted trees with null sha1s. However, this fix more
directly addresses the problem (while bogus sha1s in a tree
are probably a bad thing, it is really the sentinel
confusion sending us down the wrong code path that is what
makes it devastating). And it means that git is more capable
of examining and debugging these corrupted trees. For
example, you can still "diff --raw" such a tree to find out
when the bogus entry was introduced; you just cannot do a
"--patch" diff (just as you could not with any other
corrupted tree, as we do not have any content to diff).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
do not write null sha1s to on-disk index

We should never need to write the null sha1 into an index
entry (short of the 1 in 2^160 chance that somebody actually
has content that hashes to it). If we attempt to do so, it
is much more likely that it is a bug, since we use the null
sha1 as a sentinel value to mean "not valid".

The presence of null sha1s in the index (which can come
from, among other things, "update-index --cacheinfo", or by
reading a corrupted tree) can cause problems for later
readers, because they cannot distinguish the literal null
sha1 from its use a sentinel value.  For example, "git
diff-files" on such an entry would make it appear as if it
is stat-dirty, and until recently, the diff code assumed
such an entry meant that we should be diffing a working tree
file rather than a blob.

Ideally, we would stop such entries from entering even our
in-core index. However, we do sometimes legitimately add
entries with null sha1s in order to represent these sentinel
situations; simply forbidding them in add_index_entry breaks
a lot of the existing code. However, we can at least make
sure that our in-core sentinel representation never makes it
to disk.

To be thorough, we will test an attempt to add both a blob
and a submodule entry. In the former case, we might run into
problems anyway because we will be missing the blob object.
But in the latter case, we do not enforce connectivity
across gitlink entries, making this our only point of
enforcement. The current implementation does not care which
type of entry we are seeing, but testing both cases helps
future-proof the test suite in case that changes.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fsck: detect null sha1 in tree entries

Short of somebody happening to beat the 1 in 2^160 odds of
actually generating content that hashes to the null sha1, we
should never see this value in a tree entry. So let's have
fsck warn if it it seen.

As in the previous commit, we test both blob and submodule
entries to future-proof the test suite against the
implementation depending on connectivity to notice the
error.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
config: "git config baa" should exit with status 1

We instead failed with an undocumented exit status 255.
Also define a "catch-all" status and document it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
t7406: fix misleading "rev-parse --max-count=1 HEAD"

The test happened to use "rev-parse --max-count=1 HEAD" consistently
to prepare the expected output and the actual output, so the
comparison between them gave us a correct success/failure because
both output had irrelevant "--max-count=1" in it.

But that is not an excuse to keep it broken.  Replace it a more
meaningful construct "rev-parse --verify HEAD".

Noticed by Daniel Graña while working on his submodule tests.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
sane_execvp(): ignore non-directory on $PATH

When you have a non-directory on your PATH, a funny thing happens:

	$ PATH=$PATH:/bin/sh git foo
	fatal: cannot exec 'git-foo': Not a directory?

Worse yet, as real commands always take precedence over aliases,
this behaviour interacts rather badly with them:

	$ PATH=$PATH:/bin/sh git -c alias.foo=show git foo -s
	fatal: cannot exec 'git-foo': Not a directory?

This is because an ENOTDIR error from the underlying execvp(2) is
reported back to the caller of our sane_execvp() wrapper as-is.

Translating it to ENOENT, just like the case where we _might_ have
the command in an unreadable directory, fixes it.  Without an alias,
we would get

	git: 'foo' is not a git command. See 'git --help'.

and we use the 'foo' alias when it is available, of course.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
send-email: improve RFC2047 quote parsing

The RFC2047 unquoting, used to parse email addresses in From and Cc
headers, is broken in several ways:

* It erroneously substitutes ' ' for '_' in *the whole* header, even
  outside the quoted field. [Noticed by Christoph.]

* It is too liberal in its matching, and happily matches the start
  of one quoted chunk against the end of another, or even just
  something that looks like such an end. [Noticed by Junio.]

* It fundamentally cannot cope with encodings that are not a
  superset of ASCII, nor several (incompatible) encodings in the
  same header.

This patch fixes the first two by doing a more careful decoding of
the outer quoting (e.g. "=AB" to represent an octet whose value is
0xAB).  Fixing the fundamental issues is left for a future, more
intrusive, patch.

Noticed-by: Christoph Miebach <christoph.miebach@web.de>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
setup: clarify error messages for file/revisions ambiguity

The previous "Use '--' to separate filenames from revisions" may sound
obvious for an old-time Unix user, but does not make it clear how to use
this '--'. In addition to mentionning this '--', give an idea of what the
new command should look like.

Ideally, we could provide cut-and-paste ready commands based on the
command that just failed, but we have no easy access to argv[] in this
place of the code.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff_setup_done(): return void

diff_setup_done() has historically returned an error code, but lost
the last nonzero return in 943d5b7 (allow diff.renamelimit to be set
regardless of -M/-C, 2006-08-09).  The callers were in a pretty
confused state: some actually checked for the return code, and some
did not.

Let it return void, and patch all callers to take this into account.
This conveniently also gets rid of a handful of different(!) error
messages that could never be triggered anyway.

Note that the function can still die().

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge-recursive: eliminate flush_buffer() in favor of write_in_full()

flush_buffer() is a thin wrapper around write_in_full() with two very
confusing properties:

* It runs a loop to handle short reads, ensuring that we write
  everything.  But that is precisely what write_in_full() does!

* It checks for a return value of 0 from write_in_full(), which cannot
  happen: it returns this value only if count=0, but flush_buffer()
  will never call write_in_full() in this case.

Remove it.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
tests: Introduce test_seq

Jeff King wrote:

	The seq command is GNU-ism, and is missing at least in older BSD
	releases and their derivatives, not to mention antique
	commercial Unixes.

	We already purged it in b3431bc (Don't use seq in tests, not
	everyone has it, 2007-05-02), but a few new instances have crept
	in. They went unnoticed because they are in scripts that are not
	run by default.

Replace them with test_seq that is implemented with a Perl snippet
(proposed by Jeff).  This is better than inlining this snippet
everywhere it's needed because it's easier to read and it's easier
to change the implementation (e.g. to C) if we ever decide to remove
Perl from the test suite.

Note that test_seq is not a complete replacement for seq(1).  It
just has what we need now, in addition that it makes it possible for
us to do something like "test_seq a m" if we wanted to in the
future.

There are also many places that do `for i in 1 2 3 ...` but I'm not sure
if it's worth converting them to test_seq.  That would introduce running
more processes of Perl.

Signed-off-by: Michał Kiedrowicz <michal.kiedrowicz@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix '\ No newline...' annotation in rewrite diffs

When a file that ends with an incomplete line is expressed as a
complete rewrite with the -B option, git diff incorrectly
appends the incomplete line indicator "\ No newline at end of
file" after such a line, rather than writing it on a line of its
own (the output codepath for normal output without -B does not
have this problem).  Add a LF after the incomplete line before
writing the "\ No newline ..." out to fix this.

Add a couple of tests to confirm that the indicator comment is
generated on its own line in both plain diff and rewrite mode.

Signed-off-by: Adam Butcher <dev.lists@jessamine.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
apply: delete unused deflate_origlen from patch struct

It hasn't been used since 2006, as of commit 3cd4f5e8

    "git-apply --binary: clean up and prepare for --reverse"

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
read_index_from: remove bogus errno assignments

These assignments comes from the very first commit e83c516 (Initial
revision of "git", the information manager from hell - 2005-04-07).
Back then we did not die() when errors happened so correct errno was
required.

Since 5d1a5c0 ([PATCH] Better error reporting for "git status" -
2005-10-01), read_index_from() learned to die rather than just return
-1 and these assignments became irrelevant. Remove them.

While at it, move die_errno() next to xmmap() call because it's the
mmap's error code that we care about. Otherwise if close(fd); fails,
it could overwrite mmap's errno.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation: do not mention .git/refs/* directories

It is an implementation detail that a new tag is created by adding a
file in the .git/refs/tags directory.  The only thing the user needs
to know is that a "git tag" creates a ref in the refs/tags namespace,
and without "-f", it does not overwrite an existing tag.

Inspired by a report from 乙酸鋰 <ch3cooli@gmail.com>; I think I
caught all the existing mention in Documentation/ directory in the
tip of 1.7.9.X maintenance track, but we may have added new ones
since then.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
t/t5400: demonstrate breakage caused by informational message from prune

When receive-pack triggers 'git gc --auto' and 'git prune' is called to
remove a stale temporary object, 'git prune' prints an informational
message to stdout about the file that it will remove.  Since this message
is written to stdout, it is sent back over the transport channel to the git
client which tries to interpret it as part of the pack protocol and then
promptly terminates with a complaint about a protocol error.

Introduce a test which exercises the auto-gc functionality of receive-pack
and demonstrates this breakage.

Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
receive-pack: do not leak output from auto-gc to standard output

The standard output channel of receive-pack is a structured protocol
channel, and subprocesses must never be allowed to leak anything
into it by writing to their standard output.

Use RUN_COMMAND_STDOUT_TO_STDERR option to run_command_v_opt() just
like we do when running hooks to prevent output from "gc" leaking to
the standard output.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
docs: monospace listings in docbook output

When asciidoc converts a listing block like:

----------------------
$ git log --merge
----------------------

it marks it to be displayed in a monospace font. This works
fine when generating HTML output. However, when generating
docbook output, we override the expansion of a listingblock
to work around bugs in some versions of the docbook
toolchain. Our override did not mark the listingblock with
the "monospaced" class.

The main output that uses docbook as an intermediate format
is the manpages. We didn't notice any issue there because
the monospaced class seems to be ignored when generating
roff from the docbook manpages.

However, when generating texinfo to make info pages, docbook
does respect this class. The resulting texinfo output
properly uses "@example" blocks to display the listing in
this case. Besides possibly looking prettier in some texinfo
backends,  one important effect is that the monospace font
suppresses texinfo's expansion of "--" and "---" into
en-dashes and em-dashes.  With the current code, the example
above ends up looking like "git log -merge", which is
confusing and wrong.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
sh-setup: protect from exported IFS

Many scripted Porcelains rely on being able to split words at the
default $IFS characters, i.e. SP, HT and LF.  If the user exports a
non-default IFS to the environment, what they read from plumbing
commands such as ls-files that use HT to delimit fields may not be
split in the way we expect.

Protect outselves by resetting it, just like we do so against CDPATH
exported to the environment.

Noticed by Andrew Dranse <adranse@oanda.com>.

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