regex: use regexec_buf()

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 <regex>` 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 <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Johannes Schindelin
2016-09-21 20:24:14 +02:00
committed by Junio C Hamano
parent 2f8952250a
commit b7d36ffca0
5 changed files with 17 additions and 33 deletions

3
diff.c
View File

@ -941,7 +941,8 @@ static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
{
if (word_regex && *begin < buffer->size) {
regmatch_t match[1];
if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
if (!regexec_buf(word_regex, buffer->ptr + *begin,
buffer->size - *begin, 1, match, 0)) {
char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
'\n', match[0].rm_eo - match[0].rm_so);
*end = p ? p - buffer->ptr : match[0].rm_eo + *begin;