merge-ort: preserve cached renames for the appropriate side

Previous commits created an in-memory cache of the results of rename
detection, and added logic to detect when that cache could appropriately
be used in a subsequent merge operation -- but we were still
unconditionally clearing the cache with each new merge operation anyway.
If it is valid to reuse the cache from one of the two sides of history,
preserve that side.

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 8b2c93fdcf264e1787736ef78d2970c412d008f3..cc1adc74561dc1f6dfc168bd9bb9bb903ec4afaa 100644 (file)
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -486,17 +486,18 @@ 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) {
                strintmap_func(&renames->dirs_removed[i]);
-
-               partial_clear_dir_rename_count(&renames->dir_rename_count[i]);
-               if (!reinitialize)
-                       strmap_clear(&renames->dir_rename_count[i], 1);
-
                strmap_func(&renames->dir_renames[i], 0);
-
                strintmap_func(&renames->relevant_sources[i]);
-               strset_func(&renames->cached_target_names[i]);
-               strmap_func(&renames->cached_pairs[i], 1);
-               strset_func(&renames->cached_irrelevant[i]);
+               if (!reinitialize)
+                       assert(renames->cached_pairs_valid_side == 0);
+               if (i != renames->cached_pairs_valid_side) {
+                       strset_func(&renames->cached_target_names[i]);
+                       strmap_func(&renames->cached_pairs[i], 1);
+                       strset_func(&renames->cached_irrelevant[i]);
+                       partial_clear_dir_rename_count(&renames->dir_rename_count[i]);
+                       if (!reinitialize)
+                               strmap_clear(&renames->dir_rename_count[i], 1);
+               }
        }
        renames->cached_pairs_valid_side = 0;
        renames->dir_rename_mask = 0;
@@ -2456,6 +2457,7 @@ static void detect_regular_renames(struct merge_options *opt,
                return;
        }
 
+       partial_clear_dir_rename_count(&renames->dir_rename_count[side_index]);
        repo_diff_setup(opt->repo, &diff_opts);
        diff_opts.flags.recursive = 1;
        diff_opts.flags.rename_empty = 0;