[PATCH v2 10/13] merge-ort: preserve cached renames for the appropriate side

["Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com>]

From: Elijah Newren <newren@gmail.com>

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>
---
 merge-ort.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/merge-ort.c b/merge-ort.c
index e6a02fa928f5..b524a2db2769 100644
--- a/merge-ort.c
+++ b/merge-ort.c
@@ -476,17 +476,18 @@ 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;
@@ -2443,6 +2444,7 @@ 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;
-- 
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