delta/git.git/diffcore-pickaxe.c, branch ep/commit-static-buf-cleanup

Merge branch 'js/regexec-buf'

2016-09-26T23:09:19+00:00

Some codepaths in "git diff" used regexec(3) on a buffer that was
mmap(2)ed, which may not have a terminating NUL, leading to a read
beyond the end of the mapped region.  This was fixed by introducing
a regexec_buf() helper that takes a  pair with REG_STARTEND
extension.

* js/regexec-buf:
  regex: use regexec_buf()
  regex: add regexec_buf() that can work on a non NUL-terminated string
  regex: -G feeds a non NUL-terminated string to regexec() and fails

regex: use regexec_buf()

2016-09-21T20:56:15+00:00

The new regexec_buf() function operates on buffers with an explicitly
specified length, rather than NUL-terminated strings.

We need to use this function whenever the buffer we want to pass to
regexec(3) may have been mmap(2)ed (and is hence not NUL-terminated).

Note: the original motivation for this patch was to fix a bug where
`git diff -G ` would crash. This patch converts more callers,
though, some of which allocated to construct NUL-terminated strings,
or worse, modified buffers to temporarily insert NULs while calling
regexec(3).  By converting them to use regexec_buf(), the code has
become much cleaner.

Signed-off-by: Johannes Schindelin 
Signed-off-by: Junio C Hamano

diffcore-pickaxe: support case insensitive match on non-ascii

2016-07-01T19:44:57+00:00

Similar to the "grep -F -i" case, we can't use kws on icase search
outside ascii range, so we quote the string and pass it to regcomp as
a basic regexp and let regex engine deal with case sensitivity.

The new test is put in t7812 instead of t4209-log-pickaxe because
lib-gettext.sh might cause problems elsewhere, probably.

Noticed-by: Plamen Totev 
Signed-off-by: Nguyễn Thái Ngọc Duy 
Signed-off-by: Junio C Hamano

diffcore-pickaxe: Add regcomp_or_die()

2016-07-01T19:44:57+00:00

There's another regcomp code block coming in this function that needs
the same error handling. This function can help avoid duplicating
error handling code.

Helped-by: Jeff King 
Signed-off-by: Nguyễn Thái Ngọc Duy 
Signed-off-by: Junio C Hamano

react to errors in xdi_diff

2015-09-28T21:57:10+00:00

When we call into xdiff to perform a diff, we generally lose
the return code completely. Typically by ignoring the return
of our xdi_diff wrapper, but sometimes we even propagate
that return value up and then ignore it later.  This can
lead to us silently producing incorrect diffs (e.g., "git
log" might produce no output at all, not even a diff header,
for a content-level diff).

In practice this does not happen very often, because the
typical reason for xdiff to report failure is that it
malloc() failed (it uses straight malloc, and not our
xmalloc wrapper).  But it could also happen when xdiff
triggers one our callbacks, which returns an error (e.g.,
outf() in builtin/rerere.c tries to report a write failure
in this way). And the next patch also plans to add more
failure modes.

Let's notice an error return from xdiff and react
appropriately. In most of the diff.c code, we can simply
die(), which matches the surrounding code (e.g., that is
what we do if we fail to load a file for diffing in the
first place). This is not that elegant, but we are probably
better off dying to let the user know there was a problem,
rather than simply generating bogus output.

We could also just die() directly in xdi_diff, but the
callers typically have a bit more context, and can provide a
better message (and if we do later decide to pass errors up,
we're one step closer to doing so).

There is one interesting case, which is in diff_grep(). Here
if we cannot generate the diff, there is nothing to match,
and we silently return "no hits". This is actually what the
existing code does already, but we make it a little more
explicit.

Signed-off-by: Jeff King 
Signed-off-by: Junio C Hamano

pickaxe: simplify kwset loop in contains()

2014-03-24T22:13:17+00:00

Inlining the variable "found" actually makes the code shorter and
easier to read.

Signed-off-by: Rene Scharfe 
Signed-off-by: Junio C Hamano

pickaxe: call strlen only when necessary in diffcore_pickaxe_count()

2014-03-24T22:13:17+00:00

We need to determine the search term's length only when fixed-string
matching is used; regular expression compilation takes a NUL-terminated
string directly.  Only call strlen() in the former case.

Signed-off-by: Rene Scharfe 
Signed-off-by: Junio C Hamano

pickaxe: move pickaxe() after pickaxe_match()

2014-03-24T22:13:10+00:00

pickaxe() calls pickaxe_match(); moving the definition of the former
after the latter allows us to do without an explicit function
declaration.

Signed-off-by: Rene Scharfe 
Signed-off-by: Junio C Hamano

pickaxe: merge diffcore_pickaxe_grep() and diffcore_pickaxe_count() into diffcore_pickaxe()

2014-03-24T22:12:45+00:00

diffcore_pickaxe_count() initializes the regular expression or kwset for
the search term, calls pickaxe() with the callback has_changes() and
cleans up afterwards.  diffcore_pickaxe_grep() does the same, only it
doesn't support kwset and uses the callback diff_grep() instead.  Merge
the two functions to form the new diffcore_pickaxe() and thus get rid of
the duplicate regex setup and cleanup code.

Signed-off-by: Rene Scharfe 
Signed-off-by: Junio C Hamano

pickaxe: honor -i when used with -S and --pickaxe-regex

2014-03-24T22:12:45+00:00

accccde4 (pickaxe: allow -i to search in patch case-insensitively)
allowed case-insenitive matching for -G and -S, but for the latter
only if fixed string matching is used.  Allow it for -S and regular
expression matching as well to make the support complete.

Signed-off-by: Rene Scharfe 
Signed-off-by: Junio C Hamano