Fix bug reported by florommel on dict's reserve

m-dict.h

@@ -325,6 +325,9 @@ M_ARRAY_DEF(m_array_index, m_indexhash_t, M_POD_OPLIST)
   {                                                                           \
     map->upper_limit = (m_index_t) ((double) size * M_D1CT_OA_UPPER_BOUND) - 1; \
     map->lower_limit = (size <= M_D1CT_INITIAL_SIZE) ? 0 : (m_index_t) ((double) size * M_D1CT_OA_LOWER_BOUND) ; \
+    if (M_UNLIKELY(map->count <= map->lower_limit)) {                         \
+      map->lower_limit = 0;                                                   \
+    }                                                                         \
   }                                                                           \
                                                                               \
   M_P(void, name, _init, dict_t map)                                          \
@@ -1534,6 +1537,9 @@ enum m_d1ct_oa_element_e {
     /* FIXME: Overflow not handled. What to do in case of it? */              \
     dict->upper_limit = (size_t) ((double) size * coeff_up) - 1;              \
     dict->lower_limit = (size <= M_D1CT_INITIAL_SIZE) ? 0 : (size_t) ((double) size * coeff_down) ; \
+    if (M_UNLIKELY(dict->count <= dict->lower_limit)) {                       \
+      dict->lower_limit = 0;                                                  \
+    }                                                                         \
   }                                                                           \
                                                                               \
   M_P(void, name, _init, dict_t dict)                                         \

tests/test-mdict.c

@@ -893,6 +893,28 @@ static void test_coverage(void)
 
 }
 
+/* Reported by florommel */
+static void test_reserve_bug(void)
+{
+    dict_int_t dict;
+    dict_int_init(dict);
+
+    /* NOTE: Remove the following line to make it not fail: */
+    dict_int_reserve(dict, 32);
+
+    int k = 0;
+    for (int n = 0; n < 100; n++) {
+        for (int i = 0; i < 3; i++) {
+            dict_int_set_at(dict, ++k, 42);
+        }
+        for (int i = 0; i < 3; i++) {
+            dict_int_erase(dict, k--);
+        }
+        k += 100; /* ensure fresh keys in the next iteration */
+    }
+    dict_int_clear(dict);
+}
+
 int main(void)
 {
   test1();
@@ -905,6 +927,7 @@ int main(void)
   test_it_oa();
   test_oa_str1();
   test_oa_str2();
+  test_reserve_bug();
   testobj_final_check();
   test_coverage();
   exit(0);