merge-recursive: split out code for determining diff_filepairs

Create a new function, get_diffpairs() to compute the diff_filepairs
between two trees.  While these are currently only used in
get_renames(), I want them to be available to some new functions.  No
actual logic changes yet.

Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/merge-recursive.c b/merge-recursive.c
index 5da60b9516113ccd73418704610ad0776c2838a5..55a8ace9481bcedaabf4bb057ed2292c55cd618d 100644 (file)
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1322,24 +1322,15 @@ static int conflict_rename_rename_2to1(struct merge_options *o,
 }
 
 /*
- * Get information of all renames which occurred between 'o_tree' and
- * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
- * 'b_tree') to be able to associate the correct cache entries with
- * the rename information. 'tree' is always equal to either a_tree or b_tree.
+ * Get the diff_filepairs changed between o_tree and tree.
  */
-static struct string_list *get_renames(struct merge_options *o,
-                                      struct tree *tree,
-                                      struct tree *o_tree,
-                                      struct tree *a_tree,
-                                      struct tree *b_tree,
-                                      struct string_list *entries)
+static struct diff_queue_struct *get_diffpairs(struct merge_options *o,
+                                              struct tree *o_tree,
+                                              struct tree *tree)
 {
-       int i;
-       struct string_list *renames;
+       struct diff_queue_struct *ret;
        struct diff_options opts;
 
-       renames = xcalloc(1, sizeof(struct string_list));
-
        diff_setup(&opts);
        opts.flags.recursive = 1;
        opts.flags.rename_empty = 0;
@@ -1355,10 +1346,41 @@ static struct string_list *get_renames(struct merge_options *o,
        diffcore_std(&opts);
        if (opts.needed_rename_limit > o->needed_rename_limit)
                o->needed_rename_limit = opts.needed_rename_limit;
-       for (i = 0; i < diff_queued_diff.nr; ++i) {
+
+       ret = xmalloc(sizeof(*ret));
+       *ret = diff_queued_diff;
+
+       opts.output_format = DIFF_FORMAT_NO_OUTPUT;
+       diff_queued_diff.nr = 0;
+       diff_queued_diff.queue = NULL;
+       diff_flush(&opts);
+       return ret;
+}
+
+/*
+ * Get information of all renames which occurred in 'pairs', making use of
+ * any implicit directory renames inferred from the other side of history.
+ * We need the three trees in the merge ('o_tree', 'a_tree' and 'b_tree')
+ * to be able to associate the correct cache entries with the rename
+ * information; tree is always equal to either a_tree or b_tree.
+ */
+static struct string_list *get_renames(struct merge_options *o,
+                                      struct diff_queue_struct *pairs,
+                                      struct tree *tree,
+                                      struct tree *o_tree,
+                                      struct tree *a_tree,
+                                      struct tree *b_tree,
+                                      struct string_list *entries)
+{
+       int i;
+       struct string_list *renames;
+
+       renames = xcalloc(1, sizeof(struct string_list));
+
+       for (i = 0; i < pairs->nr; ++i) {
                struct string_list_item *item;
                struct rename *re;
-               struct diff_filepair *pair = diff_queued_diff.queue[i];
+               struct diff_filepair *pair = pairs->queue[i];
 
                if (pair->status != 'R') {
                        diff_free_filepair(pair);
@@ -1383,9 +1405,6 @@ static struct string_list *get_renames(struct merge_options *o,
                item = string_list_insert(renames, pair->one->path);
                item->util = re;
        }
-       opts.output_format = DIFF_FORMAT_NO_OUTPUT;
-       diff_queued_diff.nr = 0;
-       diff_flush(&opts);
        return renames;
 }
 
@@ -1656,15 +1675,36 @@ static int handle_renames(struct merge_options *o,
                          struct string_list *entries,
                          struct rename_info *ri)
 {
+       struct diff_queue_struct *head_pairs, *merge_pairs;
+       int clean;
+
        ri->head_renames = NULL;
        ri->merge_renames = NULL;
 
        if (!o->detect_rename)
                return 1;
 
-       ri->head_renames  = get_renames(o, head, common, head, merge, entries);
-       ri->merge_renames = get_renames(o, merge, common, head, merge, entries);
-       return process_renames(o, ri->head_renames, ri->merge_renames);
+       head_pairs = get_diffpairs(o, common, head);
+       merge_pairs = get_diffpairs(o, common, merge);
+
+       ri->head_renames  = get_renames(o, head_pairs, head,
+                                        common, head, merge, entries);
+       ri->merge_renames = get_renames(o, merge_pairs, merge,
+                                        common, head, merge, entries);
+       clean = process_renames(o, ri->head_renames, ri->merge_renames);
+
+       /*
+        * Some cleanup is deferred until cleanup_renames() because the
+        * data structures are still needed and referenced in
+        * process_entry().  But there are a few things we can free now.
+        */
+
+       free(head_pairs->queue);
+       free(head_pairs);
+       free(merge_pairs->queue);
+       free(merge_pairs);
+
+       return clean;
 }
 
 static void cleanup_rename(struct string_list *rename)