line-range: fix infinite loop bug with '$' regex
When the -L argument to "git log" is passed the zero-width regular
expression "$" (as in "-L :$:line-range.c"), this results in an
infinite loop in find_funcname_matching_regexp().
Modify find_funcname_matching_regexp to correctly match the entire line
instead of the zero-width match at eol and update the loop condition to
prevent an infinite loop in the event of other undiscovered corner cases.
The primary change is that we pre-decrement the beginning-of-line marker
('bol') before comparing it to '\n'. In the case of '$', where we match the
'\n' at the end of the line and start the loop with bol == eol, this
ensures that bol will find the beginning of the line on which the match
occurred.
Originally reported in <https://stackoverflow.com/q/74690545/147356>.
Signed-off-by: Lars Kellogg-Stedman <lars@oddbit.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/line-range.c b/line-range.c
index 955a8a9..47bf0d6 100644
--- a/line-range.c
+++ b/line-range.c
@@ -135,7 +135,7 @@ static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char
{
int reg_error;
regmatch_t match[1];
- while (1) {
+ while (*start) {
const char *bol, *eol;
reg_error = regexec(regexp, start, 1, match, 0);
if (reg_error == REG_NOMATCH)
@@ -148,8 +148,8 @@ static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char
/* determine extent of line matched */
bol = start+match[0].rm_so;
eol = start+match[0].rm_eo;
- while (bol > start && *bol != '\n')
- bol--;
+ while (bol > start && *--bol != '\n')
+ ; /* nothing */
if (*bol == '\n')
bol++;
while (*eol && *eol != '\n')
@@ -161,6 +161,7 @@ static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char
return bol;
start = eol;
}
+ return NULL;
}
static const char *parse_range_funcname(
diff --git a/t/t4211-line-log.sh b/t/t4211-line-log.sh
index ac9e4d0..c6540e8 100755
--- a/t/t4211-line-log.sh
+++ b/t/t4211-line-log.sh
@@ -315,4 +315,26 @@
test_cmp expect actual
'
+test_expect_success 'setup tests for zero-width regular expressions' '
+ cat >expect <<-EOF
+ Modify func1() in file.c
+ Add func1() and func2() in file.c
+ EOF
+'
+
+test_expect_success 'zero-width regex $ matches any function name' '
+ git log --format="%s" --no-patch "-L:$:file.c" >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'zero-width regex ^ matches any function name' '
+ git log --format="%s" --no-patch "-L:^:file.c" >actual &&
+ test_cmp expect actual
+'
+
+test_expect_success 'zero-width regex .* matches any function name' '
+ git log --format="%s" --no-patch "-L:.*:file.c" >actual &&
+ test_cmp expect actual
+'
+
test_done
