+ if (!ce)
+ fprintf(o, "%s (missing)\n", label);
+ else
+ fprintf(o, "%s%06o %s %d\t%s\n",
+ label,
+ ntohl(ce->ce_mode),
+ sha1_to_hex(ce->sha1),
+ ce_stage(ce),
+ ce->name);
+}
+#endif
+
+static int threeway_merge(struct cache_entry **stages)
+{
+ struct cache_entry *index;
+ struct cache_entry *head;
+ struct cache_entry *remote = stages[head_idx + 1];
+ int count;
+ int head_match = 0;
+ int remote_match = 0;
+
+ int df_conflict_head = 0;
+ int df_conflict_remote = 0;
+
+ int any_anc_missing = 0;
+ int i;
+
+ for (i = 1; i < head_idx; i++) {
+ if (!stages[i])
+ any_anc_missing = 1;
+ }
+
+ index = stages[0];
+ head = stages[head_idx];
+
+ if (head == &df_conflict_entry) {
+ df_conflict_head = 1;
+ head = NULL;
+ }
+
+ if (remote == &df_conflict_entry) {
+ df_conflict_remote = 1;
+ remote = NULL;
+ }
+
+ /* First, if there's a #16 situation, note that to prevent #13
+ * and #14.
+ */
+ if (!same(remote, head)) {
+ for (i = 1; i < head_idx; i++) {
+ if (same(stages[i], head)) {
+ head_match = i;
+ }
+ if (same(stages[i], remote)) {
+ remote_match = i;
+ }
+ }
+ }
+
+ /* We start with cases where the index is allowed to match
+ * something other than the head: #14(ALT) and #2ALT, where it
+ * is permitted to match the result instead.
+ */
+ /* #14, #14ALT, #2ALT */
+ if (remote && !df_conflict_head && head_match && !remote_match) {
+ if (index && !same(index, remote) && !same(index, head))
+ reject_merge(index);
+ return merged_entry(remote, index);
+ }
+ /*
+ * If we have an entry in the index cache, then we want to
+ * make sure that it matches head.
+ */
+ if (index && !same(index, head)) {
+ reject_merge(index);
+ }
+
+ if (head) {
+ /* #5ALT, #15 */
+ if (same(head, remote))
+ return merged_entry(head, index);
+ /* #13, #3ALT */
+ if (!df_conflict_remote && remote_match && !head_match)
+ return merged_entry(head, index);
+ }
+
+ /* #1 */
+ if (!head && !remote && any_anc_missing)
+ return 0;
+
+ /* Below are "no merge" cases, which require that the index be
+ * up-to-date to avoid the files getting overwritten with
+ * conflict resolution files.
+ */
+ if (index) {
+ verify_uptodate(index);
+ }
+
+ nontrivial_merge = 1;
+
+ /* #2, #3, #4, #6, #7, #9, #11. */
+ count = 0;
+ if (!head_match || !remote_match) {
+ for (i = 1; i < head_idx; i++) {
+ if (stages[i]) {
+ keep_entry(stages[i]);
+ count++;
+ break;
+ }
+ }
+ }
+#if DBRT_DEBUG
+ else {
+ fprintf(stderr, "read-tree: warning #16 detected\n");
+ show_stage_entry(stderr, "head ", stages[head_match]);
+ show_stage_entry(stderr, "remote ", stages[remote_match]);
+ }
+#endif
+ if (head) { count += keep_entry(head); }
+ if (remote) { count += keep_entry(remote); }
+ return count;