commit-graph: fix memory leak when not writing graph

When `write_commit_graph()` bails out writing a split commit-graph early
then it may happen that we have already gathered the set of existing
commit-graph file names without yet determining the new merged set of
files. This can result in a memory leak though because we only clear the
preimage of files when we have collected the postimage.

Fix this issue by dropping the condition altogether so that we always
try to free both preimage and postimage filenames. As the context
structure is zero-initialized this simplification is safe to do.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Acked-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 8 insertions, 11 deletions

diff --git a/commit-graph.c b/commit-graph.c
index bba316913c..a30a4fc993 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -2616,19 +2616,16 @@ cleanup:
 	oid_array_clear(&ctx->oids);
 	clear_topo_level_slab(&topo_levels);
 
-	if (ctx->commit_graph_filenames_after) {
-		for (i = 0; i < ctx->num_commit_graphs_after; i++) {
-			free(ctx->commit_graph_filenames_after[i]);
-			free(ctx->commit_graph_hash_after[i]);
-		}
-
-		for (i = 0; i < ctx->num_commit_graphs_before; i++)
-			free(ctx->commit_graph_filenames_before[i]);
+	for (i = 0; i < ctx->num_commit_graphs_before; i++)
+		free(ctx->commit_graph_filenames_before[i]);
+	free(ctx->commit_graph_filenames_before);
 
-		free(ctx->commit_graph_filenames_after);
-		free(ctx->commit_graph_filenames_before);
-		free(ctx->commit_graph_hash_after);
+	for (i = 0; i < ctx->num_commit_graphs_after; i++) {
+		free(ctx->commit_graph_filenames_after[i]);
+		free(ctx->commit_graph_hash_after[i]);
 	}
+	free(ctx->commit_graph_filenames_after);
+	free(ctx->commit_graph_hash_after);
 
 	free(ctx);