directory rename detection: more involved edge/corner testcases

diff --git a/merge-recursive.c b/merge-recursive.c
index a4c280dfc78e943ec541f83ccb0b39921ccdf2b2..cedb7c37727666105b51d193899d3b1b8db0aec6 100644 (file)
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -513,6 +513,25 @@ static void record_df_conflict_files(struct merge_options *o,
 
 struct rename {
        struct diff_filepair *pair;
+       /*
+        * Purpose of src_entry and dst_entry:
+        *
+        * If 'before' is renamed to 'after' then src_entry will contain
+        * the versions of 'before' from the merge_base, HEAD, and MERGE in
+        * stages 1, 2, and 3; dst_entry will contain the respective
+        * versions of 'after' in corresponding locations.  Thus, we have a
+        * total of six modes and oids, though some will be null.  (Stage 0
+        * is ignored; we're interested in handling conflicts.)
+        *
+        * Since we don't turn on break-rewrites by default, neither
+        * src_entry nor dst_entry can have all three of their stages have
+        * non-null oids, meaning at most four of the six will be non-null.
+        * Also, since this is a rename, both src_entry and dst_entry will
+        * have at least one non-null oid, meaning at least two will be
+        * non-null.  Of the six oids, a typical rename will have three be
+        * non-null.  Only two implies a rename/delete, and four implies a
+        * rename/add.
+        */
        struct stage_data *src_entry;
        struct stage_data *dst_entry;
        unsigned processed:1;
@@ -646,7 +665,7 @@ static int remove_file(struct merge_options *o, int clean,
                if (ignore_case) {
                        struct cache_entry *ce;
                        ce = cache_file_exists(path, strlen(path), ignore_case);
-                       if (ce && ce_stage(ce) == 0)
+                       if (ce && ce_stage(ce) == 0 && strcmp(path, ce->name))
                                return 0;
                }
                if (remove_path(path))
@@ -1952,6 +1971,13 @@ int merge_trees(struct merge_options *o,
        }
 
        if (oid_eq(&common->object.oid, &merge->object.oid)) {
+               struct strbuf sb = STRBUF_INIT;
+
+               if (!o->call_depth && index_has_changes(&sb)) {
+                       err(o, _("Dirty index: cannot merge (dirty: %s)"),
+                           sb.buf);
+                       return 0;
+               }
                output(o, 0, _("Already up to date!"));
                *result = head;
                return 1;
@@ -1982,10 +2008,10 @@ int merge_trees(struct merge_options *o,
                get_files_dirs(o, merge);
 
                entries = get_unmerged();
-               record_df_conflict_files(o, entries);
                re_head  = get_renames(o, head, common, head, merge, entries);
                re_merge = get_renames(o, merge, common, head, merge, entries);
                clean = process_renames(o, re_head, re_merge);
+               record_df_conflict_files(o, entries);
                if (clean < 0)
                        goto cleanup;
                for (i = entries->nr-1; 0 <= i; i--) {