trailing = frag->trailing;
/*
- * If we don't have any leading/trailing data in the patch,
- * we want it to match at the beginning/end of the file.
+ * A hunk to change lines at the beginning would begin with
+ * @@ -1,L +N,M @@
*
- * But that would break if the patch is generated with
- * --unified=0; sane people wouldn't do that to cause us
- * trouble, but we try to please not so sane ones as well.
+ * And a hunk to add to an empty file would begin with
+ * @@ -0,0 +N,M @@
+ *
+ * In other words, a hunk that is (frag->oldpos <= 1) with or
+ * without leading context must match at the beginning.
*/
- if (unidiff_zero) {
- match_beginning = (!leading && !frag->oldpos);
- match_end = 0;
- }
- else {
- match_beginning = !leading && (frag->oldpos == 1);
- match_end = !trailing;
- }
+ match_beginning = frag->oldpos <= 1;
+
+ /*
+ * A hunk without trailing lines must match at the end.
+ * However, we simply cannot tell if a hunk must match end
+ * from the lack of trailing lines if the patch was generated
+ * with unidiff without any context.
+ */
+ match_end = !unidiff_zero && !trailing;
pos = frag->newpos ? (frag->newpos - 1) : 0;
preimage.buf = oldlines;