[PATCH v2 16/33] merge-recursive: introduce new functions to handle rename logic

[Elijah Newren <newren@gmail.com>]

The amount of logic in merge_trees() relative to renames was just a few
lines, but split it out into new handle_renames() and cleanup_renames()
functions to prepare for additional logic to be added to each.  No code or
logic changes, just a new place to put stuff for when the rename detection
gains additional checks.

Note that process_renames() records pointers to various information (such
as diff_filepairs) into rename_conflict_info structs.  Even though the
rename string_lists are not directly used once handle_renames() completes,
we should not immediately free the lists at the end of that function
because they store the information referenced in the rename_conflict_info,
which is used later in process_entry().  Thus the reason for a separate
cleanup_renames().

Signed-off-by: Elijah Newren <newren@gmail.com>
---
 merge-recursive.c | 43 +++++++++++++++++++++++++++++++++----------
 1 file changed, 33 insertions(+), 10 deletions(-)

diff --git a/merge-recursive.c b/merge-recursive.c
index 91bc354bec..4249caad4d 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -1636,6 +1636,32 @@ static int process_renames(struct merge_options *o,
 	return clean_merge;
 }
 
+struct rename_info {
+	struct string_list *head_renames;
+	struct string_list *merge_renames;
+};
+
+static int handle_renames(struct merge_options *o,
+			  struct tree *common,
+			  struct tree *head,
+			  struct tree *merge,
+			  struct string_list *entries,
+			  struct rename_info *ri)
+{
+	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);
+}
+
+static void cleanup_renames(struct rename_info *re_info)
+{
+	string_list_clear(re_info->head_renames, 0);
+	string_list_clear(re_info->merge_renames, 0);
+
+	free(re_info->head_renames);
+	free(re_info->merge_renames);
+}
+
 static struct object_id *stage_oid(const struct object_id *oid, unsigned mode)
 {
 	return (is_null_oid(oid) || mode == 0) ? NULL: (struct object_id *)oid;
@@ -1987,7 +2013,8 @@ int merge_trees(struct merge_options *o,
 	}
 
 	if (unmerged_cache()) {
-		struct string_list *entries, *re_head, *re_merge;
+		struct string_list *entries;
+		struct rename_info re_info;
 		int i;
 		/*
 		 * Only need the hashmap while processing entries, so
@@ -2001,9 +2028,8 @@ int merge_trees(struct merge_options *o,
 		get_files_dirs(o, merge);
 
 		entries = get_unmerged();
-		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);
+		clean = handle_renames(o, common, head, merge, entries,
+				       &re_info);
 		record_df_conflict_files(o, entries);
 		if (clean < 0)
 			goto cleanup;
@@ -2028,16 +2054,13 @@ int merge_trees(struct merge_options *o,
 		}
 
 cleanup:
-		string_list_clear(re_merge, 0);
-		string_list_clear(re_head, 0);
+		cleanup_renames(&re_info);
+
 		string_list_clear(entries, 1);
+		free(entries);
 
 		hashmap_free(&o->current_file_dir_set, 1);
 
-		free(re_merge);
-		free(re_head);
-		free(entries);
-
 		if (clean < 0)
 			return clean;
 	}
-- 
2.15.0.309.g00c152f825