Treat D/F conflict entry more carefully in unpack-trees.c::threeway_merge()

This fixes three buglets in threeway_merge() regarding D/F
conflict entries.

* After finishing with path D and handling path D/F, some stages
  have D/F conflict entry which are obviously non-NULL.  For the
  purpose of determining if the path D/F is missing in the
  ancestor, they should not be taken into account.

* D/F conflict entry is a marker to say "this stage does _not_
  have the path", so do not send them to keep_entry().

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/unpack-trees.c b/unpack-trees.c
index 2a58b7fa286fbe5e450c40daa6210818065af0d8..5139481358d0838a95db3fdb62e32221eb7343b1 100644 (file)
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -665,7 +665,6 @@ int threeway_merge(struct cache_entry **stages,
        int count;
        int head_match = 0;
        int remote_match = 0;
-       const char *path = NULL;
 
        int df_conflict_head = 0;
        int df_conflict_remote = 0;
@@ -675,13 +674,10 @@ int threeway_merge(struct cache_entry **stages,
        int i;
 
        for (i = 1; i < o->head_idx; i++) {
-               if (!stages[i])
+               if (!stages[i] || stages[i] == o->df_conflict_entry)
                        any_anc_missing = 1;
-               else {
-                       if (!path)
-                               path = stages[i]->name;
+               else
                        no_anc_exists = 0;
-               }
        }
 
        index = stages[0];
@@ -697,13 +693,6 @@ int threeway_merge(struct cache_entry **stages,
                remote = NULL;
        }
 
-       if (!path && index)
-               path = index->name;
-       if (!path && head)
-               path = head->name;
-       if (!path && remote)
-               path = remote->name;
-
        /* First, if there's a #16 situation, note that to prevent #13
         * and #14.
         */
@@ -755,6 +744,23 @@ int threeway_merge(struct cache_entry **stages,
        if (o->aggressive) {
                int head_deleted = !head && !df_conflict_head;
                int remote_deleted = !remote && !df_conflict_remote;
+               const char *path = NULL;
+
+               if (index)
+                       path = index->name;
+               else if (head)
+                       path = head->name;
+               else if (remote)
+                       path = remote->name;
+               else {
+                       for (i = 1; i < o->head_idx; i++) {
+                               if (stages[i] && stages[i] != o->df_conflict_entry) {
+                                       path = stages[i]->name;
+                                       break;
+                               }
+                       }
+               }
+
                /*
                 * Deleted in both.
                 * Deleted in one and unchanged in the other.
@@ -790,7 +796,7 @@ int threeway_merge(struct cache_entry **stages,
        count = 0;
        if (!head_match || !remote_match) {
                for (i = 1; i < o->head_idx; i++) {
-                       if (stages[i]) {
+                       if (stages[i] && stages[i] != o->df_conflict_entry) {
                                keep_entry(stages[i], o);
                                count++;
                                break;