@matheusbsbs / matheus-bagliano / commits / 4e57c88e02

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>

Lars Kellogg-Stedman committed Dec 19, 2022 at 17:48 UTC 4e57c88e028c25ee9428b51ff829299bbb88a80c

2 files changed +26 -3

line-range.c

+4 -3

@@ -135,7 +135,7 @@ static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char

135 {

136 int reg_error;

137 regmatch_t match[1];

138 - while (1) {

138 + while (*start) {

139 const char *bol, *eol;

140 reg_error = regexec(regexp, start, 1, match, 0);

141 if (reg_error == REG_NOMATCH)

@@ -148,8 +148,8 @@ static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char

148 /* determine extent of line matched */

149 bol = start+match[0].rm_so;

150 eol = start+match[0].rm_eo;

151 - while (bol > start && *bol != '\n')

152 - bol--;

151 + while (bol > start && *--bol != '\n')

152 + ; /* nothing */

153 if (*bol == '\n')

154 bol++;

155 while (*eol && *eol != '\n')

@@ -161,6 +161,7 @@ static const char *find_funcname_matching_regexp(xdemitconf_t *xecfg, const char

161 return bol;

162 start = eol;

163 }

164 + return NULL;

165 }

166

167 static const char *parse_range_funcname(

t/t4211-line-log.sh

+22

@@ -315,4 +315,26 @@ test_expect_success 'line-log with --before' '

315 test_cmp expect actual

316 '

317

318 +test_expect_success 'setup tests for zero-width regular expressions' '

319 + cat >expect <<-EOF

320 + Modify func1() in file.c

321 + Add func1() and func2() in file.c

322 + EOF

323 +'

324 +

325 +test_expect_success 'zero-width regex $ matches any function name' '

326 + git log --format="%s" --no-patch "-L:$:file.c" >actual &&

327 + test_cmp expect actual

328 +'

329 +

330 +test_expect_success 'zero-width regex ^ matches any function name' '

331 + git log --format="%s" --no-patch "-L:^:file.c" >actual &&

332 + test_cmp expect actual

333 +'

334 +

335 +test_expect_success 'zero-width regex .* matches any function name' '

336 + git log --format="%s" --no-patch "-L:.*:file.c" >actual &&

337 + test_cmp expect actual

338 +'

339 +

340 test_done