gc: reject if another gc is running, unless --force is given

This may happen when `git gc --auto` is run automatically, then the
user, to avoid wait time, switches to a new terminal, keeps working
and `git gc --auto` is started again because the first gc instance has
not clean up the repository.

This patch tries to avoid multiple gc running, especially in --auto
mode. In the worst case, gc may be delayed 12 hours if a daemon reuses
the pid stored in gc.pid.

kill(pid, 0) support is added to MinGW port so it should work on
Windows too.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
builtin/config.c: compilation fix

Do not feed a random string as the first parameter to die(); use "%s"
as the format string instead.

Do the same for test-urlmatch-normalization.c while saving a single
pointer variable by turning a "const char *" constant string into
"const char []", which is sufficient to squelch compilation warning
(the compiler can see usage[] given to die() is a constant and will
never have conversion specifiers that cause trouble).  But for a
good measure, give them the same "%s" treatment as well.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff: remove ternary operator evaluating always to true

The line being changed is deep inside the function builtin_diff.
The variable name_b, which is used to evaluate the ternary expression
must evaluate to true at that position, hence the replacement with
just name_b.

The name_b variable only occurs a few times in that lengthy function:
As a parameter to the function itself:
	static void builtin_diff(const char *name_a,
				 const char *name_b,
				...
The next occurrences are at:
	/* Never use a non-valid filename anywhere if at all possible */
	name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
	name_b = DIFF_FILE_VALID(two) ? name_b : name_a;

	a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
	b_two = quote_two(b_prefix, name_b + (*name_b == '/'));

In the last line of this block 'name_b' is dereferenced and compared
to '/'. This would crash if name_b was NULL. Hence in the following code
we can assume name_b being non-null.

The next occurrence is just as a function argument, which doesn't change
the memory, which name_b points to, so the assumption name_b being not
null still holds:
	emit_rewrite_diff(name_a, name_b, one, two,
				textconv_one, textconv_two, o);

The next occurrence would be the line of this patch. As name_b still must
be not null, we can remove the ternary operator.

Inside the emit_rewrite_diff function there is a also a line
	ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
which was also simplified as there is also a dereference before the
ternary operator.

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff: fix a possible null pointer dereference

The condition in the ternary operator was wrong, hence the wrong char
pointer could be used as the parameter for show_submodule_summary.
one->path may be null, but we definitely need a non null path given
to the function.

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Acked-By: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
rm: remove unneeded null pointer check

As of 7612a1efdb (2006-06-09 git-rm: honor -n flag.) the variable
'pathspec' seems to be assumed to be never NULL after calling get_pathspec
There was a NULL pointer check after the seen = NULL assignment, which
was removed by that commit. So if pathspec would be NULL now, we'd segfault
in the line accessing the pathspec:
	for (i = 0; pathspec[i] ; i++)

A few lines later, 'pathspec' still cannot be NULL, but that check was
overlooked, hence removing it now.

As the null pointer check was removed, it makes no sense to assign NULL
to seen and 3 lines later another value as there are no conditions in
between.

Signed-off-by: Stefan Beller <stefanbeller@googlemail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
core-tutorial: trim the section on Inspecting Changes

Back when the core tutorial was written, `log` and `whatchanged`
were scripted Porcelains.  In the "Inspecting Changes" section that
talks about the plumbing commands in the diff family, it made sense
to use `log` and `whatchanged` as good examples of the use of these
plumbing commands, and because even these scripted Porcelains were
novelty (there wasn't the new end-user tutorial written), it made
some sense to illustrate uses of the `git log` (and `git
whatchanged`) scripted Porcelain commands.

But we no longer have scripted `log` and `whatchanged` to serve as
examples, and this document is not where the end users learn what
`git log` command is about.  Stop at briefly mentioning the
possibility of combining rev-list with diff-tree to build your own
log, and leave the end-user documentation of `log` to the new
tutorial and the user manual.

Also resurrect the last version of `git-log`, `git-whatchanged`, and
`git-show` to serve as examples to contrib/examples/ directory.

While at it, remove 'whatchanged' from a list of sample commands
that are affected by GIT_FLUSH environment variable. This is not
meant to be an exhaustive list but as a list of typical ones, and an
old command that is kept primarily for backward compatibility does
not belong to it.

Helped-by: Matthieu Moy <Matthieu.Moy@grenoble-inp.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
whatchanged: document its historical nature

Encourage new users to use 'log' instead.  These days, these
commands are unified and just have different defaults.

'git log' only allowed you to view the log messages and no diffs
when it was added in early June 2005.  It was only in early April
2006 that the command learned to take diff options.  Because of
this, power users tended to use 'whatchanged' that already existed
since mid May 2005 and supported diff options.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation/git-merge-file: document option "--diff3"

The option "--diff3" was added to "git merge-file" in e0af48e
(xdiff-merge: optionally show conflicts in "diff3 -m" style)
but it was never documented in "Documentation/git-merge-file.txt".
Add documentation for this option.

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-hg: fix path when cloning with tilde expansion

The current code fixes the path to make it absolute when cloning, but
doesn't consider tilde expansion, so that scenario fails throwing an
exception because /home/myuser/~/my/repository doesn't exists:

    $ git clone hg::~/my/repository && cd repository && git fetch

Expand the tilde when checking if the path is absolute, so that we don't
fix a path that doesn't need to be.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'jc/url-match' into jch

Allow section.<urlpattern>.var configuration variables to be
treated as a "virtual" section.var given a URL, and use the
mechanism to enhance http.* configuration variables.

Reroll of km/http-curl-config-per-url topic.

* jc/url-match:
  builtin/config.c: compilation fix
  config: "git config --get-urlmatch" parses section.<url>.key
  builtin/config: refactor collect_config()
  config: parse http.<url>.<variable> using urlmatch
  config: add generic callback wrapper to parse section.<url>.key
  config: add helper to normalize and match URLs
  http.c: fix parsing of http.sslCertPasswordProtected variable
Merge branch 'es/blame-L-twice' into jch

Teaches "git blame" to take more than one -L ranges.

* es/blame-L-twice:
  line-range: reject -L line numbers less than 1
  t8001/t8002: blame: add tests of -L line numbers less than 1
  line-range: teach -L^:RE to search from start of file
  line-range: teach -L:RE to search from end of previous -L range
  line-range: teach -L^/RE/ to search from start of file
  line-range-format.txt: document -L/RE/ relative search
  log: teach -L/RE/ to search from end of previous -L range
  blame: teach -L/RE/ to search from end of previous -L range
  line-range: teach -L/RE/ to search relative to anchor point
  blame: document multiple -L support
  t8001/t8002: blame: add tests of multiple -L options
  blame: accept multiple -L ranges
  blame: inline one-line function into its lone caller
  range-set: publish API for re-use by git-blame -L
  line-range-format.txt: clarify -L:regex usage form
  git-log.txt: place each -L option variation on its own line
Merge branch 'mm/no-shell-escape-in-die-message' into jch

Fixes a minor bug in "git rebase -i" (there could be others, as the
root cause is pretty generic) where the code feeds a random, data
dependeant string to 'echo' and expects it to come out literally.

* mm/no-shell-escape-in-die-message:
  die_with_status: use "printf '%s\n'", not "echo"
Merge branch 'tr/fd-gotcha-fixes' into jch

Finishing touches to an earlier fix already in 'master'.

* tr/fd-gotcha-fixes:
  t0070: test that git_mkstemps correctly checks return value of open()
Merge branch 'sb/parseopt-boolean-removal' into jch

Convert most uses of OPT_BOOLEAN/OPTION_BOOLEAN that can use
OPT_BOOL/OPTION_BOOLEAN which have much saner semantics, and turn
remaining ones into OPT_SET_INT, OPT_COUNTUP, etc. as necessary;
there seems to be some misconversion that makes many tests fail,
though.

* sb/parseopt-boolean-removal:
  revert: use the OPT_CMDMODE for parsing, reducing code
  checkout-index: fix negations of even numbers of -n
  config parsing options: allow one flag multiple times
  hash-object: replace stdin parsing OPT_BOOLEAN by OPT_COUNTUP
  branch, commit, name-rev: ease up boolean conditions
  checkout: remove superfluous local variable
  log, format-patch: parsing uses OPT__QUIET
  Replace deprecated OPT_BOOLEAN by OPT_BOOL
  Remove deprecated OPTION_BOOLEAN for parsing arguments

# Conflicts:
# 	builtin/check-attr.c
# 	builtin/check-ignore.c
Merge branch 'jl/submodule-mv' into jch

"git mv A B" when moving a submodule A does "the right thing",
inclusing relocating its working tree and adjusting the paths in
the .gitmodules file.

* jl/submodule-mv:
  rm: delete .gitmodules entry of submodules removed from the work tree
  mv: update the path entry in .gitmodules for moved submodules
  submodule.c: add .gitmodules staging helper functions
  mv: move submodules using a gitfile
  mv: move submodules together with their work trees
### match next
Merge branch 'jn/post-receive-utf8' into jch

Update post-receive-email script to make sure the message contents
and pathnames are encoded consistently in UTF-8.

I have a feeling that it is a lost cause to solve the issue the
topic tries to address in general, because the patch text can have
payload in any encodings that are different from either the
pathnames or the log message.  Patches that touch paths that use an
encoding that conflicts with the encoding of the payload and/or the
log message could be transferred with core.quotepath set and patch
generated as all binary, but that would be pretty much useless.

* jn/post-receive-utf8:
  hooks/post-receive-email: set declared encoding to utf-8
  hooks/post-receive-email: force log messages in UTF-8
  hooks/post-receive-email: use plumbing instead of git log/show
Merge branch 'jc/transport-do-not-use-connect-twice-in-fetch' into jch

* jc/transport-do-not-use-connect-twice-in-fetch:
  fetch: work around "transport-take-over" hack
  fetch: refactor code that fetches leftover tags
  fetch: refactor code that prepares a transport
  fetch: rename file-scope global "transport" to "gtransport"
  t5802: add test for connect helper

Conflicts:
	builtin/fetch.c
Merge branch 'ap/remote-hg-tilde-is-home-directory' into jch

* ap/remote-hg-tilde-is-home-directory:
  remote-hg: fix path when cloning with tilde expansion
  .mailmap: fixup entries
  t/t7407: fix two typos in submodule tests
  l10n: de.po: translate 5 messages
  l10n: de.po: translate 99 new messages
  l10n: de.po: switch from pure German to German+English
  l10n: de.po: Fix a typo
  l10n: Update Swedish translation (2135t0f0u)
  l10n: zh_CN.po: translate 5 messages (2135t0f0u)
  l10n: vi.po(2135t): v1.8.4 round 2
  l10n: git.pot: v1.8.4 round 2 (5 new, 3 removed)
Merge branch 'rt/doc-merge-file-diff3' into jch

* rt/doc-merge-file-diff3:
  Documentation/git-merge-file: document option "--diff3"
  parse-options: fix clang opterror() -Wunused-value warning