+struct combine_diff_state {
+ struct xdiff_emit_state xm;
+
+ unsigned int lno;
+ int ob, on, nb, nn;
+ unsigned long nmask;
+ int num_parent;
+ int n;
+ struct sline *sline;
+ struct sline *lost_bucket;
+};
+
+static void consume_line(void *state_, char *line, unsigned long len)
+{
+ struct combine_diff_state *state = state_;
+ if (5 < len && !memcmp("@@ -", line, 4)) {
+ if (parse_hunk_header(line, len,
+ &state->ob, &state->on,
+ &state->nb, &state->nn))
+ return;
+ state->lno = state->nb;
+ if (!state->nb)
+ /* @@ -1,2 +0,0 @@ to remove the
+ * first two lines...
+ */
+ state->nb = 1;
+ if (state->nn == 0)
+ /* @@ -X,Y +N,0 @@ removed Y lines
+ * that would have come *after* line N
+ * in the result. Our lost buckets hang
+ * to the line after the removed lines,
+ */
+ state->lost_bucket = &state->sline[state->nb];
+ else
+ state->lost_bucket = &state->sline[state->nb-1];
+ if (!state->sline[state->nb-1].p_lno)
+ state->sline[state->nb-1].p_lno =
+ xcalloc(state->num_parent,
+ sizeof(unsigned long));
+ state->sline[state->nb-1].p_lno[state->n] = state->ob;
+ return;
+ }
+ if (!state->lost_bucket)
+ return; /* not in any hunk yet */
+ switch (line[0]) {
+ case '-':
+ append_lost(state->lost_bucket, state->n, line+1, len-1);
+ break;
+ case '+':
+ state->sline[state->lno-1].flag |= state->nmask;
+ state->lno++;
+ break;
+ }
+}
+
+static void combine_diff(const unsigned char *parent, mmfile_t *result_file,