+/* Check whether two filespecs with the same mode and size are identical */
+static int diff_filespec_is_identical(struct diff_filespec *one,
+ struct diff_filespec *two)
+{
+ if (S_ISGITLINK(one->mode)) {
+ diff_fill_sha1_info(one);
+ diff_fill_sha1_info(two);
+ return !hashcmp(one->sha1, two->sha1);
+ }
+ if (diff_populate_filespec(one, 0))
+ return 0;
+ if (diff_populate_filespec(two, 0))
+ return 0;
+ return !memcmp(one->data, two->data, one->size);
+}
+
+static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
+{
+ int i;
+ struct diff_queue_struct *q = &diff_queued_diff;
+ struct diff_queue_struct outq;
+ outq.queue = NULL;
+ outq.nr = outq.alloc = 0;
+
+ for (i = 0; i < q->nr; i++) {
+ struct diff_filepair *p = q->queue[i];
+
+ /*
+ * 1. Entries that come from stat info dirtyness
+ * always have both sides (iow, not create/delete),
+ * one side of the object name is unknown, with
+ * the same mode and size. Keep the ones that
+ * do not match these criteria. They have real
+ * differences.
+ *
+ * 2. At this point, the file is known to be modified,
+ * with the same mode and size, and the object
+ * name of one side is unknown. Need to inspect
+ * the identical contents.
+ */
+ if (!DIFF_FILE_VALID(p->one) || /* (1) */
+ !DIFF_FILE_VALID(p->two) ||
+ (p->one->sha1_valid && p->two->sha1_valid) ||
+ (p->one->mode != p->two->mode) ||
+ diff_populate_filespec(p->one, 1) ||
+ diff_populate_filespec(p->two, 1) ||
+ (p->one->size != p->two->size) ||
+ !diff_filespec_is_identical(p->one, p->two)) /* (2) */
+ diff_q(&outq, p);
+ else {
+ /*
+ * The caller can subtract 1 from skip_stat_unmatch
+ * to determine how many paths were dirty only
+ * due to stat info mismatch.
+ */
+ if (!diffopt->no_index)
+ diffopt->skip_stat_unmatch++;
+ diff_free_filepair(p);
+ }
+ }
+ free(q->queue);
+ *q = outq;
+}
+