test: test a corner case in hashmap_remove_and_replace()

1 files changed, 20 insertions, 0 deletions

diff --git a/src/test/test-hashmap-plain.c b/src/test/test-hashmap-plain.c
index f7917521c5..d27d5ec819 100644
--- a/src/test/test-hashmap-plain.c
+++ b/src/test/test-hashmap-plain.c
@@ -380,6 +380,7 @@ static void test_hashmap_remove_and_replace(void) {
         void *key2 = UINT_TO_PTR(2);
         void *key3 = UINT_TO_PTR(3);
         void *r;
+        int i, j;
 
         m = hashmap_new(&trivial_hash_ops);
         assert_se(m);
@@ -407,6 +408,25 @@ static void test_hashmap_remove_and_replace(void) {
         r = hashmap_get(m, key2);
         assert_se(r == key2);
         assert_se(!hashmap_get(m, key3));
+
+        /* Repeat this test several times to increase the chance of hitting
+         * the less likely case in hashmap_remove_and_replace where it
+         * compensates for the backward shift. */
+        for (i = 0; i < 20; i++) {
+                hashmap_clear(m);
+
+                for (j = 1; j < 7; j++)
+                        hashmap_put(m, UINT_TO_PTR(10*i + j), UINT_TO_PTR(10*i + j));
+                valid = hashmap_remove_and_replace(m, UINT_TO_PTR(10*i + 1),
+                                                   UINT_TO_PTR(10*i + 2),
+                                                   UINT_TO_PTR(10*i + 2));
+                assert_se(valid == 0);
+                assert_se(!hashmap_get(m, UINT_TO_PTR(10*i + 1)));
+                for (j = 2; j < 7; j++) {
+                        r = hashmap_get(m, UINT_TO_PTR(10*i + j));
+                        assert_se(r == UINT_TO_PTR(10*i + j));
+                }
+        }
 }
 
 static void test_hashmap_ensure_allocated(void) {