Do nothing when freeing NULL (#141)

src/array.c

@@ -203,7 +203,8 @@ bk_err array_get(void *const data, array me, const size_t index)
 
 /**
  * Frees the array memory. Performing further operations after calling this
- * function results in undefined behavior.
+ * function results in undefined behavior. Freeing NULL is legal, and causes
+ * no operation to be performed.
  *
  * @param me the array to free from memory
  *

src/deque.c

@@ -646,7 +646,8 @@ bk_err deque_clear(deque me)
 
 /**
  * Destroys the deque. Performing further operations after calling this function
- * results in undefined behavior.
+ * results in undefined behavior. Freeing NULL is legal, and causes no operation
+ * to be performed.
  *
  * @param me the deque to destroy
  *
@@ -654,11 +655,13 @@ bk_err deque_clear(deque me)
  */
 deque deque_destroy(deque me)
 {
-    size_t i;
-    for (i = me->alloc_block_start; i <= me->alloc_block_end; i++) {
-        free(me->data[i]);
+    if (me) {
+        size_t i;
+        for (i = me->alloc_block_start; i <= me->alloc_block_end; i++) {
+            free(me->data[i]);
+        }
+        free(me->data);
+        free(me);
     }
-    free(me->data);
-    free(me);
     return NULL;
 }

src/forward_list.c

@@ -488,7 +488,8 @@ void forward_list_clear(forward_list me)
 
 /**
  * Destroys the singly-linked list. Performing further operations after calling
- * this function results in undefined behavior.
+ * this function results in undefined behavior. Freeing NULL is legal, and
+ * causes no operation to be performed.
  *
  * @param me the singly-linked list to destroy
  *
@@ -496,7 +497,9 @@ void forward_list_clear(forward_list me)
  */
 forward_list forward_list_destroy(forward_list me)
 {
-    forward_list_clear(me);
-    free(me);
+    if (me) {
+        forward_list_clear(me);
+        free(me);
+    }
     return NULL;
 }

src/list.c

@@ -512,7 +512,8 @@ void list_clear(list me)
 
 /**
  * Destroys the doubly-linked list. Performing further operations after calling
- * this function results in undefined behavior.
+ * this function results in undefined behavior. Freeing NULL is legal, and
+ * causes no operation to be performed.
  *
  * @param me the doubly-linked list to destroy
  *
@@ -520,7 +521,9 @@ void list_clear(list me)
  */
 list list_destroy(list me)
 {
-    list_clear(me);
-    free(me);
+    if (me) {
+        list_clear(me);
+        free(me);
+    }
     return NULL;
 }

src/map.c

@@ -886,7 +886,8 @@ void map_clear(map me)
 
 /**
  * Frees the map memory. Performing further operations after calling this
- * function results in undefined behavior.
+ * function results in undefined behavior. Freeing NULL is legal, and causes
+ * no operation to be performed.
  *
  * @param me the map to free from memory
  *
@@ -894,7 +895,9 @@ void map_clear(map me)
  */
 map map_destroy(map me)
 {
-    map_clear(me);
-    free(me);
+    if (me) {
+        map_clear(me);
+        free(me);
+    }
     return NULL;
 }

src/multimap.c

@@ -1075,7 +1075,8 @@ void multimap_clear(multimap me)
 
 /**
  * Frees the multi-map memory. Performing further operations after calling this
- * function results in undefined behavior.
+ * function results in undefined behavior. Freeing NULL is legal, and causes no
+ * operation to be performed.
  *
  * @param me the multi-map to free from memory
  *
@@ -1083,7 +1084,9 @@ void multimap_clear(multimap me)
  */
 multimap multimap_destroy(multimap me)
 {
-    multimap_clear(me);
-    free(me);
+    if (me) {
+        multimap_clear(me);
+        free(me);
+    }
     return NULL;
 }

src/multiset.c

@@ -929,7 +929,8 @@ void multiset_clear(multiset me)
 
 /**
  * Frees the multi-set memory. Performing further operations after calling this
- * function results in undefined behavior.
+ * function results in undefined behavior. Freeing NULL is legal, and causes no
+ * operation to be performed.
  *
  * @param me the multi-set to free from memory
  *
@@ -937,7 +938,9 @@ void multiset_clear(multiset me)
  */
 multiset multiset_destroy(multiset me)
 {
-    multiset_clear(me);
-    free(me);
+    if (me) {
+        multiset_clear(me);
+        free(me);
+    }
     return NULL;
 }

src/priority_queue.c

@@ -236,7 +236,8 @@ bk_err priority_queue_clear(priority_queue me)
 
 /**
  * Frees the priority queue memory. Performing further operations after calling
- * this function results in undefined behavior.
+ * this function results in undefined behavior. Freeing NULL is legal, and
+ * causes no operation to be performed.
  *
  * @param me the priority queue to free from memory
  *
@@ -244,7 +245,9 @@ bk_err priority_queue_clear(priority_queue me)
  */
 priority_queue priority_queue_destroy(priority_queue me)
 {
-    vector_destroy(me->data);
-    free(me);
+    if (me) {
+        vector_destroy(me->data);
+        free(me);
+    }
     return NULL;
 }

src/queue.c

@@ -174,7 +174,8 @@ bk_err queue_clear(queue me)
 
 /**
  * Destroys the queue. Performing further operations after calling this function
- * results in undefined behavior.
+ * results in undefined behavior. Freeing NULL is legal, and causes no operation
+ * to be performed.
  *
  * @param me the queue to destroy
  *

src/set.c

@@ -849,7 +849,8 @@ void set_clear(set me)
 
 /**
  * Frees the set memory. Performing further operations after calling this
- * function results in undefined behavior.
+ * function results in undefined behavior. Freeing NULL is legal, and causes
+ * no operation to be performed.
  *
  * @param me the set to free from memory
  *
@@ -857,7 +858,9 @@ void set_clear(set me)
  */
 set set_destroy(set me)
 {
-    set_clear(me);
-    free(me);
+    if (me) {
+        set_clear(me);
+        free(me);
+    }
     return NULL;
 }

src/stack.c

@@ -158,7 +158,8 @@ bk_err stack_clear(stack me)
 
 /**
  * Frees the stack memory. Performing further operations after calling this
- * function results in undefined behavior.
+ * function results in undefined behavior. Freeing NULL is legal, and causes
+ * no operation to be performed.
  *
  * @param me the stack to destroy
  *

src/unordered_map.c

@@ -440,7 +440,8 @@ int unordered_map_clear(unordered_map me)
 
 /**
  * Frees the unordered map memory. Performing further operations after calling
- * this function results in undefined behavior.
+ * this function results in undefined behavior. Freeing NULL is legal, and
+ * causes no operation to be performed.
  *
  * @param me the unordered map to free from memory
  *
@@ -448,8 +449,10 @@ int unordered_map_clear(unordered_map me)
  */
 unordered_map unordered_map_destroy(unordered_map me)
 {
-    unordered_map_clear(me);
-    free(me->buckets);
-    free(me);
+    if (me) {
+        unordered_map_clear(me);
+        free(me->buckets);
+        free(me);
+    }
     return NULL;
 }

src/unordered_multimap.c

@@ -577,7 +577,8 @@ bk_err unordered_multimap_clear(unordered_multimap me)
 
 /**
  * Frees the unordered multi-map memory. Performing further operations after
- * calling this function results in undefined behavior.
+ * calling this function results in undefined behavior. Freeing NULL is legal,
+ * and causes no operation to be performed.
  *
  * @param me the unordered multi-map to free from memory
  *
@@ -585,9 +586,11 @@ bk_err unordered_multimap_clear(unordered_multimap me)
  */
 unordered_multimap unordered_multimap_destroy(unordered_multimap me)
 {
-    unordered_multimap_clear(me);
-    free(me->iterate_key);
-    free(me->buckets);
-    free(me);
+    if (me) {
+        unordered_multimap_clear(me);
+        free(me->iterate_key);
+        free(me->buckets);
+        free(me);
+    }
     return NULL;
 }

src/unordered_multiset.c

@@ -501,7 +501,8 @@ bk_err unordered_multiset_clear(unordered_multiset me)
 
 /**
  * Frees the unordered multi-set memory. Performing further operations after
- * calling this function results in undefined behavior.
+ * calling this function results in undefined behavior. Freeing NULL is legal,
+ * and causes no operation to be performed.
  *
  * @param me the unordered multi-set to free from memory
  *
@@ -509,8 +510,10 @@ bk_err unordered_multiset_clear(unordered_multiset me)
  */
 unordered_multiset unordered_multiset_destroy(unordered_multiset me)
 {
-    unordered_multiset_clear(me);
-    free(me->buckets);
-    free(me);
+    if (me) {
+        unordered_multiset_clear(me);
+        free(me->buckets);
+        free(me);
+    }
     return NULL;
 }

src/unordered_set.c

@@ -393,7 +393,8 @@ int unordered_set_clear(unordered_set me)
 
 /**
  * Frees the unordered set memory. Performing further operations after calling
- * this function results in undefined behavior.
+ * this function results in undefined behavior. Freeing NULL is legal, and
+ * causes no operation to be performed.
  *
  * @param me the unordered set to free from memory
  *
@@ -401,8 +402,10 @@ int unordered_set_clear(unordered_set me)
  */
 unordered_set unordered_set_destroy(unordered_set me)
 {
-    unordered_set_clear(me);
-    free(me->buckets);
-    free(me);
+    if (me) {
+        unordered_set_clear(me);
+        free(me->buckets);
+        free(me);
+    }
     return NULL;
 }

src/vector.c

@@ -489,7 +489,8 @@ bk_err vector_clear(vector me)
 
 /**
  * Frees the vector memory. Performing further operations after calling this
- * function results in undefined behavior.
+ * function results in undefined behavior. Freeing NULL is legal, and causes
+ * no operation to be performed.
  *
  * @param me the vector to free from memory
  *
@@ -497,7 +498,9 @@ bk_err vector_clear(vector me)
  */
 vector vector_destroy(vector me)
 {
-    free(me->data);
-    free(me);
+    if (me) {
+        free(me->data);
+        free(me);
+    }
     return NULL;
 }

tst/test_array.c

@@ -160,4 +160,5 @@ void test_array(void)
 #endif
     test_big_object();
     test_add_all();
+    array_destroy(NULL);
 }

tst/test_deque.c

@@ -674,4 +674,5 @@ void test_deque(void)
     test_block_reuse_forwards();
     test_block_reuse_backwards();
     test_trim_both_sides();
+    deque_destroy(NULL);
 }

tst/test_forward_list.c

@@ -444,4 +444,5 @@ void test_forward_list(void)
     assert(test_puzzle_backwards(2, 10) == 5);
     test_big_object();
     test_add_all();
+    forward_list_destroy(NULL);
 }

tst/test_list.c

@@ -432,4 +432,5 @@ void test_list(void)
     assert(test_puzzle_backwards(2, 10) == 5);
     test_big_object();
     test_add_all();
+    list_destroy(NULL);
 }

tst/test_map.c

@@ -711,4 +711,5 @@ void test_map(void)
 #endif
     test_big_object();
     test_ordered_retrieval();
+    map_destroy(NULL);
 }

tst/test_multimap.c

@@ -786,4 +786,5 @@ void test_multimap(void)
 #endif
     test_big_object();
     test_ordered_retrieval();
+    multimap_destroy(NULL);
 }

tst/test_multiset.c

@@ -715,4 +715,5 @@ void test_multiset(void)
 #endif
     test_big_object();
     test_ordered_retrieval();
+    multiset_destroy(NULL);
 }

tst/test_priority_queue.c

@@ -239,4 +239,5 @@ void test_priority_queue(void)
     test_push_out_of_memory();
 #endif
     test_big_object();
+    priority_queue_destroy(NULL);
 }

tst/test_queue.c

@@ -188,4 +188,5 @@ void test_queue(void)
     assert(test_puzzle(2, 5) == 4);
     assert(test_puzzle(2, 10) == 5);
     test_big_object();
+    queue_destroy(NULL);
 }

tst/test_set.c

@@ -683,4 +683,5 @@ void test_set(void)
 #endif
     test_big_object();
     test_ordered_retrieval();
+    set_destroy(NULL);
 }

tst/test_stack.c

@@ -112,4 +112,5 @@ void test_stack(void)
     test_basic();
     test_automated_trim();
     test_big_object();
+    stack_destroy(NULL);
 }

tst/test_unordered_map.c

@@ -355,4 +355,5 @@ void test_unordered_map(void)
     test_clear_out_of_memory();
 #endif
     test_big_object();
+    unordered_map_destroy(NULL);
 }

tst/test_unordered_multimap.c

@@ -478,4 +478,5 @@ void test_unordered_multimap(void)
     test_clear_out_of_memory();
 #endif
     test_big_object();
+    unordered_multimap_destroy(NULL);
 }

tst/test_unordered_multiset.c

@@ -402,4 +402,5 @@ void test_unordered_multiset(void)
     test_clear_out_of_memory();
 #endif
     test_big_object();
+    unordered_multiset_destroy(NULL);
 }

tst/test_unordered_set.c

@@ -342,4 +342,5 @@ void test_unordered_set(void)
     test_clear_out_of_memory();
 #endif
     test_big_object();
+    unordered_set_destroy(NULL);
 }

tst/test_vector.c

@@ -354,4 +354,5 @@ void test_vector(void)
 #endif
     test_big_object();
     test_add_all();
+    vector_destroy(NULL);
 }