merge-ort: add a paths_to_free field to merge_options_internal

This field will be used in future patches to allow removal of paths from
opt->priv->paths.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/merge-ort.c b/merge-ort.c
index d88307489be1cd2c9c4a39e94e29d67379458330..ae855a4ae531069b01d8789e276d4c1cb4b895e8 100644 (file)
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -58,6 +58,8 @@ struct merge_options_internal {
         *   * these keys serve to intern all the path strings, which allows
         *     us to do pointer comparison on directory names instead of
         *     strcmp; we just have to be careful to use the interned strings.
+        *     (Technically paths_to_free may track some strings that were
+        *      removed from froms paths.)
         *
         * The values of paths:
         *   * either a pointer to a merged_info, or a conflict_info struct
@@ -92,6 +94,16 @@ struct merge_options_internal {
         */
        struct strmap conflicted;
 
+       /*
+        * paths_to_free: additional list of strings to free
+        *
+        * If keys are removed from "paths", they are added to paths_to_free
+        * to ensure they are later freed.  We avoid free'ing immediately since
+        * other places (e.g. conflict_info.pathnames[]) may still be
+        * referencing these paths.
+        */
+       struct string_list paths_to_free;
+
        /*
         * current_dir_name: temporary var used in collect_merge_info_callback()
         *
@@ -249,6 +261,17 @@ static void clear_internal_opts(struct merge_options_internal *opti,
         * don't free the keys and we pass 0 for free_values.
         */
        strmap_clear(&opti->conflicted, 0);
+
+       /*
+        * opti->paths_to_free is similar to opti->paths; we created it with
+        * strdup_strings = 0 to avoid making _another_ copy of the fullpath
+        * but now that we've used it and have no other references to these
+        * strings, it is time to deallocate them.  We do so by temporarily
+        * setting strdup_strings to 1.
+        */
+       opti->paths_to_free.strdup_strings = 1;
+       string_list_clear(&opti->paths_to_free, 0);
+       opti->paths_to_free.strdup_strings = 0;
 }
 
 static int err(struct merge_options *opt, const char *err, ...)
@@ -1243,13 +1266,14 @@ static void merge_start(struct merge_options *opt, struct merge_result *result)
         * Although we initialize opt->priv->paths with strdup_strings=0,
         * that's just to avoid making yet another copy of an allocated
         * string.  Putting the entry into paths means we are taking
-        * ownership, so we will later free it.
+        * ownership, so we will later free it.  paths_to_free is similar.
         *
         * In contrast, conflicted just has a subset of keys from paths, so
         * we don't want to free those (it'd be a duplicate free).
         */
        strmap_init_with_options(&opt->priv->paths, NULL, 0);
        strmap_init_with_options(&opt->priv->conflicted, NULL, 0);
+       string_list_init(&opt->priv->paths_to_free, 0);
 }
 
 /*