apply.c:update_pre_post_images(): the preimage can be truncated

5166714 (apply: Allow blank context lines to match beyond EOF,
2010-03-06) and then later 0c3ef98 (apply: Allow blank *trailing*
context lines to match beyond EOF, 2010-04-08) taught "git apply"
to trim new blank lines at the end in the patch text when matching
the contents being patched and the preimage recorded in the patch,
under --whitespace=fix mode.

When a preimage is modified to match the current contents in
preparation for such a "fixed" patch application, the context lines
in the postimage must be updated to match (otherwise, it would
reintroduce whitespace breakages), and update_pre_post_images()
function is responsible for doing this.  However, this function was
not updated to take into account a case where the removal of
trailing blank lines reduces the number of lines in the preimage,
and triggered an assertion error.

The logic to fix the postimage by copying the corrected context
lines from the preimage was not prepared to handle this case,
either, but it was protected by the assert() and only got exposed
when the assertion is corrected.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
config, gitignore: failure to access with ENOTDIR is ok

The access_or_warn() function is used to check for optional
configuration files like .gitconfig and .gitignore and warn when they
are not accessible due to a configuration issue (e.g., bad
permissions).  It is not supposed to complain when a file is simply
missing.

Noticed on a system where ~/.config/git was a file --- when the new
XDG_CONFIG_HOME support looks for ~/.config/git/config it should
ignore ~/.config/git instead of printing irritating warnings:

 $ git status -s
 warning: unable to access '/home/jrn/.config/git/config': Not a directory
 warning: unable to access '/home/jrn/.config/git/config': Not a directory
 warning: unable to access '/home/jrn/.config/git/config': Not a directory
 warning: unable to access '/home/jrn/.config/git/config': Not a directory

Compare v1.7.12.1~2^2 (attr:failure to open a .gitattributes file
is OK with ENOTDIR, 2012-09-13).

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
config: treat user and xdg config permission problems as errors

Git reads multiple configuration files: settings come first from the
system config file (typically /etc/gitconfig), then the xdg config
file (typically ~/.config/git/config), then the user's dotfile
(~/.gitconfig), then the repository configuration (.git/config).

Git has always used access(2) to decide whether to use each file; as
an unfortunate side effect, that means that if one of these files is
unreadable (e.g., EPERM or EIO), git skips it.  So if I use
~/.gitconfig to override some settings but make a mistake and give it
the wrong permissions then I am subject to the settings the sysadmin
chose for /etc/gitconfig.

Better to error out and ask the user to correct the problem.

This only affects the user and xdg config files, since the user
presumably has enough access to fix their permissions.  If the system
config file is unreadable, the best we can do is to warn about it so
the user knows to notify someone and get on with work in the meantime.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
doc: advertise GIT_CONFIG_NOSYSTEM

On a multiuser system where mortals do not have write access to /etc,
the GIT_CONFIG_NOSYSTEM variable is the best tool we have to keep
getting work done when a syntax error or other problem renders
/etc/gitconfig buggy, until the sysadmin sorts the problem out.

Noticed while experimenting with teaching git to error out when
/etc/gitconfig is unreadable.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
config: exit on error accessing any config file

There is convenience in warning and moving on when somebody has a
bogus permissions on /etc/gitconfig and cannot do anything about it.
But the cost in predictability and security is too high --- when
unreadable config files are skipped, it means an I/O error or
permissions problem causes important configuration to be bypassed.

For example, servers may depend on /etc/gitconfig to enforce security
policy (setting transfer.fsckObjects or receive.deny*).  Best to
always error out when encountering trouble accessing a config file.

This may add inconvenience in some cases:

  1. You are inspecting somebody else's repo, and you do not have
     access to their .git/config file.  Git typically dies in this
     case already since we cannot read core.repositoryFormatVersion,
     so the change should not be too noticeable.

  2. You have used "sudo -u" or a similar tool to switch uid, and your
     environment still points Git at your original user's global
     config, which is not readable.  In this case people really would
     be inconvenienced (they would rather see the harmless warning and
     continue the operation) but they can work around it by setting
     HOME appropriately after switching uids.

  3. You do not have access to /etc/gitconfig due to a broken setup.
     In this case, erroring out is a good way to put pressure on the
     sysadmin to fix the setup.  While they wait for a reply, users
     can set GIT_CONFIG_NOSYSTEM to true to keep Git working without
     complaint.

After this patch, errors accessing the repository-local and systemwide
config files and files requested in include directives cause Git to
exit, just like errors accessing ~/.gitconfig.

Explained-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
ctype: make sane_ctype[] const array

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
ctype: support iscntrl, ispunct, isxdigit and isprint

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Import wildmatch from rsync

These files are from rsync.git commit
f92f5b166e3019db42bc7fe1aa2f1a9178cd215d, which was the last commit
before rsync turned GPL-3. All files are imported as-is and
no-op. Adaptation is done in a separate patch.

rsync.git           ->  git.git
lib/wildmatch.[ch]      wildmatch.[ch]
wildtest.txt            t/t3070/wildtest.txt

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
wildmatch: remove unnecessary functions

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
wildmatch: follow Git's coding convention

wildmatch's coding style is pretty close to Git's except the use of 4
space indentation instead of 8. This patch should produce empty diff
with "git diff -b"

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Integrate wildmatch to git

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t3070: disable unreliable fnmatch tests

These tests show different results on different fnmatch() versions. We
don't want to test fnmatch here. We want to make sure wildmatch
behavior matches fnmatch and that only makes sense in cases when
fnmatch() behaves consistently.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
wildmatch: make wildmatch's return value compatible with fnmatch

wildmatch returns non-zero if matched, zero otherwise. This patch
makes it return zero if matches, non-zero otherwise, like fnmatch().

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
wildmatch: remove static variable force_lower_case

One place less to worry about thread safety. Also combine wildmatch
and iwildmatch into one.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
wildmatch: fix case-insensitive matching

dowild() does case insensitive matching by lower-casing the text. That
means lower case letters in patterns imply case-insensitive matching,
but upper case means exact matching.

We do not want that subtlety. Lower case pattern too so iwildmatch()
always does what we expect it to do.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
wildmatch: adjust "**" behavior

Standard wildmatch() sees consecutive asterisks as "*" that can also
match slashes. But that may be hard to explain to users as
"abc/**/def" can match "abcdef", "abcxyzdef", "abc/def", "abc/x/def",
"abc/x/y/def"...

This patch changes wildmatch so that users can do

- "**/def" -> all paths ending with file/directory 'def'
- "abc/**" - equivalent to "/abc/"
- "abc/**/def" -> "abc/x/def", "abc/x/y/def"...
- otherwise consider the pattern malformed if "**" is found

Basically the magic of "**" only remains if it's wrapped around by
slashes.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
wildmatch: make /**/ match zero or more directories

"foo/**/bar" matches "foo/x/bar", "foo/x/y/bar"... but not
"foo/bar". We make a special case, when foo/**/ is detected (and
"foo/" part is already matched), try matching "bar" with the rest of
the string.

"Match one or more directories" semantics can be easily achieved using
"foo/*/**/bar".

This also makes "**/foo" match "foo" in addition to "x/foo",
"x/y/foo"..

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Support "**" wildcard in .gitignore and .gitattributes

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'jl/submodule-rm' into next

"git rm submodule" cannot blindly remove a submodule directory as
its working tree may have local changes, and worse yet, it may even
have its repository embedded in it.  Teach it some special cases
where it is safe to remove a submodule, specifically, when there is
no local changes in the submodule working tree, and its repository
is not embedded in its working tree but is elsewhere and uses the
gitfile mechanism to point at it.

Will merge to 'master' in the second batch after 1.8.0 ships.

* jl/submodule-rm:
  submodule: teach rm to remove submodules unless they contain a git directory
Merge branch 'jl/submodule-add-by-name' into next

If you remove a submodule, in order to keep the repository so that
"git checkout" to an older commit in the superproject history can
resurrect the submodule, the real repository will stay in $GIT_DIR
of the superproject.  A later "git submodule add $path" to add a
different submodule at the same path will fail.  Diagnose this case
a bit better, and if the user really wants to add an unrelated
submodule at the same path, give the "--name" option to give it a
place in $GIT_DIR of the superproject that does not conflict with
the original submodule.

Will merge to 'master' in the second batch after 1.8.0 ships.

* jl/submodule-add-by-name:
  submodule add: Fail when .git/modules/<name> already exists unless forced
  Teach "git submodule add" the --name option