+static int depth_first(const void *a_, const void *b_)
+{
+ const struct diff_filepair *a = *((const struct diff_filepair **)a_);
+ const struct diff_filepair *b = *((const struct diff_filepair **)b_);
+ const char *name_a, *name_b;
+ int len_a, len_b, len;
+ int cmp;
+
+ name_a = a->one ? a->one->path : a->two->path;
+ name_b = b->one ? b->one->path : b->two->path;
+
+ len_a = strlen(name_a);
+ len_b = strlen(name_b);
+ len = (len_a < len_b) ? len_a : len_b;
+
+ /* strcmp will sort 'd' before 'd/e', we want 'd/e' before 'd' */
+ cmp = memcmp(name_a, name_b, len);
+ if (cmp)
+ return cmp;
+ return (len_b - len_a);
+}
+