Improve test coverage

3 files changed, 7 insertions, 5 deletions

diff --git a/src/allocator.c b/src/allocator.c
index ca91803..af6b8a9 100644
--- a/src/allocator.c
+++ b/src/allocator.c
@@ -60,9 +60,10 @@ zix_default_aligned_alloc(ZixAllocator* const allocator,
 #if defined(_WIN32)
   return _aligned_malloc(size, alignment);
 #elif USE_POSIX_MEMALIGN
-  void*     ptr = NULL;
-  const int ret = posix_memalign(&ptr, alignment, size);
-  return ret ? NULL : ptr;
+  // POSIX.1-2008 TC2 says that ptr is not modified on failure
+  void* ptr = NULL;
+  posix_memalign(&ptr, alignment, size);
+  return ptr;
 #else
   return NULL;
 #endif
diff --git a/src/ring.c b/src/ring.c
index 10b31e5..ca957e2 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -275,10 +275,10 @@ zix_ring_write(ZixRing* const ring, const void* src, const uint32_t size)
 {
   ZixRingTransaction tx = zix_ring_begin_write(ring);
 
-  if (zix_ring_amend_write(ring, &tx, src, size) ||
-      zix_ring_commit_write(ring, &tx)) {
+  if (zix_ring_amend_write(ring, &tx, src, size)) {
     return 0;
   }
 
+  zix_ring_commit_write(ring, &tx);
   return size;
 }
diff --git a/test/test_allocator.c b/test/test_allocator.c
index e146de6..425cc41 100644
--- a/test/test_allocator.c
+++ b/test/test_allocator.c
@@ -83,6 +83,7 @@ test_bump_allocator(void)
 
   assert(!zix_realloc(&allocator.base, malloced, 8));     // Not the top
   assert(!zix_realloc(&allocator.base, realloced, 4089)); // No space
+  assert(!zix_calloc(&allocator.base, 4089, 1));          // No space
 
   zix_free(&allocator.base, realloced);