push: start warning upcoming default change for push.default

In preparation for flipping the default to the "simple" mode from
the "matching" mode that is the historical default, start warning
users when they rely on unconfigured "git push" to default to the
"matching" mode.

Also, advertise for 'simple' where 'current' and 'upstream' are advised.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: Simplify print_tool_help()

Eliminate a global variable and File::Find usage by building upon
basename() and glob() instead.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: Eliminate global variables

Organize the script so that it has a single main() function which
calls out to dir_diff() and file_diff() functions. This eliminates
"dir-diff"-specific variables that do not need to be calculated when
performing a regular file-diff.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: Move option values into a hash

Shorten the "my" declaration for all of the option-specific variables
by wrapping all of them in a hash.  This also gives us a place to
specify default values, should we need them.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: Call the temp directory "git-difftool"

The "diffall" name was left over from when this functionality was part of
the "git-diffall" script in contrib/.  Make the naming consistent.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: Use symlinks when diffing against the worktree

Teach difftool's --dir-diff mode to use symlinks to represent
files from the working copy, and make it the default behavior
for the non-Windows platforms.

Using symlinks is simpler and safer since we do not need to
worry about copying files back into the worktree.
The old behavior is still available as --no-symlinks.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: Handle finding mergetools/ in a path with spaces

Use the original File::Find implementation from bf73fc2 (difftool:
print list of valid tools with '--tool-help', 2012-03-29) so that we
properly handle mergetools/ being located in a path containing
spaces.

One small difference is that we avoid using a global variable by
passing a reference to the list of tools.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: Check all return codes from compare()

Handle the case where compare() is unable to read its inputs.
Emit a warning so that the user knows that something went wrong.

We may later want to restructure the code so that we can inhibit
tempdir cleanup when this condition is reached.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: Wrap long lines for readability

Keep everything within 80 columns.  Wrap the user-facing messages too.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: Handle compare() returning -1

Keep the temporary directory around when compare()
cannot read its input files, which is indicated by -1.

Defer tempdir creation to allow an early exit in setup_dir_diff().
Wrap the rest of the entry points in an exit_cleanup() function
to handle removing temporary files and error reporting.

Print the temporary files' location so that the user can
recover them.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
difftool: Disable --symlinks on cygwin

Symlinks are not ubiquitous on Windows so make --no-symlinks the default.

Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remove unnecessary parameter from get_patch_ids()

get_patch_ids() takes an already initialized rev_info and a
prefix. The prefix is used when initalizing a second rev_info. Since
the initialized rev_info already has a prefix and the prefix never
changes, we can use the prefix from the initialized rev_info to
initialize the second rev_info.

Signed-off-by: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
cherry: don't set ignored rev_info options

Ever since cherry was built-in in e827633 (Built-in cherry,
2006-10-24), it has set a bunch of options on the the rev_info that
are only used while outputting a patch. But since the built-in cherry
command never needs to output any patch (it uses add_commit_patch_id
and has_commit_patch_id instead), these options are just distractions,
so remove them.

Signed-off-by: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cherry: remove redundant check for merge commit

While walking the revision list in get_patch_ids and cmd_cherry, we
check for each commit if there is more than one parent and ignore
the commit if that is the case. Instead, set rev_info.max_parents to
1 and let the revision traversal code handle it for us.

Signed-off-by: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com>
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>
grep: add a grep.patternType configuration setting

The grep.extendedRegexp configuration setting enables the -E flag on grep
by default but there are no equivalents for the -G, -F and -P flags.

Rather than adding an additional setting for grep.fooRegexp for current
and future pattern matching options, add a grep.patternType setting that
can accept appropriate values for modifying the default grep pattern
matching behavior. The current values are "basic", "extended", "fixed",
"perl" and "default" for setting -G, -E, -F, -P and the default behavior
respectively.

When grep.patternType is set to a value other than "default", the
grep.extendedRegexp setting is ignored. The value of "default" restores
the current default behavior, including the grep.extendedRegexp
behavior.

Signed-off-by: J Smith <dark.panda@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
include agent identifier in capability string

Instead of having the client advertise a particular version
number in the git protocol, we have managed extensions and
backwards compatibility by having clients and servers
advertise capabilities that they support. This is far more
robust than having each side consult a table of
known versions, and provides sufficient information for the
protocol interaction to complete.

However, it does not allow servers to keep statistics on
which client versions are being used. This information is
not necessary to complete the network request (the
capabilities provide enough information for that), but it
may be helpful to conduct a general survey of client
versions in use.

We already send the client version in the user-agent header
for http requests; adding it here allows us to gather
similar statistics for non-http requests.

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