diffcore-rename: add function for clearing dir_rename_count

As we adjust the usage of dir_rename_count we want to have a function
for clearing, or partially clearing it out.  Add a
partial_clear_dir_rename_count() function for this purpose.

Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diffcore-rename.c

@@ -528,6 +528,18 @@ static void initialize_dir_rename_info(struct dir_rename_info *info)
 	}
 }
 
+void partial_clear_dir_rename_count(struct strmap *dir_rename_count)
+{
+	struct hashmap_iter iter;
+	struct strmap_entry *entry;
+
+	strmap_for_each_entry(dir_rename_count, &iter, entry) {
+		struct strintmap *counts = entry->value;
+		strintmap_clear(counts);
+	}
+	strmap_partial_clear(dir_rename_count, 1);
+}
+
 static void cleanup_dir_rename_info(struct dir_rename_info *info)
 {
 	if (!info->setup)

diffcore.h

@@ -161,6 +161,8 @@ struct diff_filepair *diff_queue(struct diff_queue_struct *,
 				 struct diff_filespec *);
 void diff_q(struct diff_queue_struct *, struct diff_filepair *);
 
+void partial_clear_dir_rename_count(struct strmap *dir_rename_count);
+
 void diffcore_break(struct repository *, int);
 void diffcore_rename(struct diff_options *);
 void diffcore_rename_extended(struct diff_options *options,

merge-ort.c

@@ -351,17 +351,11 @@ static void clear_or_reinit_internal_opts(struct merge_options_internal *opti,
 
 	/* Free memory used by various renames maps */
 	for (i = MERGE_SIDE1; i <= MERGE_SIDE2; ++i) {
-		struct hashmap_iter iter;
-		struct strmap_entry *entry;
-
 		strset_func(&renames->dirs_removed[i]);
 
-		strmap_for_each_entry(&renames->dir_rename_count[i],
+		partial_clear_dir_rename_count(&renames->dir_rename_count[i]);
-				      &iter, entry) {
+		if (!reinitialize)
-			struct strintmap *counts = entry->value;
+			strmap_clear(&renames->dir_rename_count[i], 1);
-			strintmap_clear(counts);
-		}
-		strmap_func(&renames->dir_rename_count[i], 1);
 
 		strmap_func(&renames->dir_renames[i], 0);
 	}