cov: test for fixture being NULL pointer

Explicit check for teoretical NULL pointer passed as fixture.

test/unit/bcache_t.c

@@ -349,10 +349,12 @@ static struct fixture *_fixture_init(sector_t block_size, unsigned nr_cache_bloc
 
 static void _fixture_exit(struct fixture *f)
 {
-	_expect(f->me, E_DESTROY);
-	bcache_destroy(f->cache);
+	if (f) {
+		_expect(f->me, E_DESTROY);
+		bcache_destroy(f->cache);
 
-	free(f);
+		free(f);
+	}
 }
 
 static void *_small_fixture_init(void)

test/unit/bcache_utils_t.c

@@ -109,11 +109,13 @@ static void _fix_exit(void *fixture)
 {
         struct fixture *f = fixture;
 
-	bcache_destroy(f->cache);
-	close(f->fd);
-	bcache_clear_fd(f->di);
-	unlink(f->fname);
-        free(f);
+	if (f) {
+		bcache_destroy(f->cache);
+		(void) close(f->fd);
+		bcache_clear_fd(f->di);
+		(void) unlink(f->fname);
+		free(f);
+	}
 }
 
 //----------------------------------------------------------------

test/unit/bitset_t.c

@@ -31,7 +31,8 @@ static void *_mem_init(void) {
 
 static void _mem_exit(void *mem)
 {
-	dm_pool_destroy(mem);
+	if (mem)
+		dm_pool_destroy(mem);
 }
 
 static void test_get_next(void *fixture)

test/unit/io_engine_t.c

@@ -104,13 +104,15 @@ static void _fix_exit(void *fixture)
 {
         struct fixture *f = fixture;
 
-	close(f->fd);
-	bcache_clear_fd(f->di);
-	unlink(f->fname);
-        free(f->data);
-        if (f->e)
-                f->e->destroy(f->e);
-        free(f);
+	if (f) {
+		(void) close(f->fd);
+		bcache_clear_fd(f->di);
+		(void) unlink(f->fname);
+		free(f->data);
+		if (f->e)
+			f->e->destroy(f->e);
+		free(f);
+	}
 }
 
 static void _test_create(void *fixture)

test/unit/radix_tree_t.c

@@ -28,7 +28,8 @@ static void *rt_init(void)
 
 static void rt_exit(void *fixture)
 {
-	radix_tree_destroy(fixture);
+	if (fixture)
+		radix_tree_destroy(fixture);
 }
 
 static void test_create_destroy(void *fixture)