refactor: introduce XFREE_CLEAR()

Unfortunately we cannot indiscriminately replace xfree() with
XFREE_CLEAR(), because comparing pointers after freeing them is a common
pattern. Example in `tv_list_remove_items()`:

    xfree(li);
    if (li == item2) {
      break;
    }

Instead we can do it selectively/explicitly.

ref #1375

1 files changed, 3 insertions, 3 deletions

diff --git a/src/nvim/lib/kvec.h b/src/nvim/lib/kvec.h
index 93b2f053bc..e668b10bb9 100644
--- a/src/nvim/lib/kvec.h
+++ b/src/nvim/lib/kvec.h
@@ -58,7 +58,7 @@
     }
 
 #define kv_init(v) ((v).size = (v).capacity = 0, (v).items = 0)
-#define kv_destroy(v) xfree((v).items)
+#define kv_destroy(v) XFREE_CLEAR((v).items)
 #define kv_A(v, i) ((v).items[(i)])
 #define kv_pop(v) ((v).items[--(v).size])
 #define kv_size(v) ((v).size)
@@ -138,7 +138,7 @@ static inline void *_memcpy_free(void *const restrict dest,
   FUNC_ATTR_NONNULL_ALL FUNC_ATTR_NONNULL_RET FUNC_ATTR_ALWAYS_INLINE
 {
   memcpy(dest, src, size);
-  xfree(src);
+  XFREE_CLEAR(src);
   return dest;
 }
 
@@ -201,7 +201,7 @@ static inline void *_memcpy_free(void *const restrict dest,
 #define kvi_destroy(v) \
     do { \
       if ((v).items != (v).init_array) { \
-        xfree((v).items); \
+        XFREE_CLEAR((v).items); \
       } \
     } while (0)