@matheusbsbs / matheus-bagliano / commits / 61f883965f

xdiff: handle allocation failure in patience diff

Other users of libxdiff such as libgit2 need to be able to handle allocation failures. As NULL is a valid return value the function signature is changed to be able report allocation failures. Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Phillip Wood committed Feb 16, 2022 at 10:15 UTC 61f883965f79308b849a55936bee69a33c476c5c

1 file changed +12 -5

xdiff/xpatience.c

+12 -5

@@ -198,7 +198,7 @@ static int binary_search(struct entry **sequence, int longest,

198 * item per sequence length: the sequence with the smallest last

199 * element (in terms of line2).

200 */

201 -static struct entry *find_longest_common_sequence(struct hashmap *map)

201 +static int find_longest_common_sequence(struct hashmap *map, struct entry **res)

202 {

203 struct entry **sequence = xdl_malloc(map->nr * sizeof(struct entry *));

204 int longest = 0, i;

@@ -211,6 +211,9 @@ static struct entry *find_longest_common_sequence(struct hashmap *map)

211 */

212 int anchor_i = -1;

213

214 + if (!sequence)

215 + return -1;

216 +

217 for (entry = map->first; entry; entry = entry->next) {

218 if (!entry->line2 || entry->line2 == NON_UNIQUE)

219 continue;

@@ -230,8 +233,9 @@ static struct entry *find_longest_common_sequence(struct hashmap *map)

233

234 /* No common unique lines were found */

235 if (!longest) {

236 + *res = NULL;

237 xdl_free(sequence);

234 - return NULL;

238 + return 0;

239 }

240

241 /* Iterate starting at the last element, adjusting the "next" members */

@@ -241,8 +245,9 @@ static struct entry *find_longest_common_sequence(struct hashmap *map)

245 entry->previous->next = entry;

246 entry = entry->previous;

247 }

248 + *res = entry;

249 xdl_free(sequence);

245 - return entry;

250 + return 0;

251 }

252

253 static int match(struct hashmap *map, int line1, int line2)

@@ -358,14 +363,16 @@ static int patience_diff(mmfile_t *file1, mmfile_t *file2,

363 return 0;

364 }

365

361 - first = find_longest_common_sequence(&map);

366 + result = find_longest_common_sequence(&map, &first);

367 + if (result)

368 + goto out;

369 if (first)

370 result = walk_common_sequence(&map, first,

371 line1, count1, line2, count2);

372 else

373 result = fall_back_to_classic_diff(&map,

374 line1, count1, line2, count2);

368 -

375 + out:

376 xdl_free(map.entries);

377 return result;

378 }