Merge branch 'ab/free-and-null'

A common pattern to free a piece of memory and assign NULL to the
pointer that used to point at it has been replaced with a new
FREE_AND_NULL() macro.

* ab/free-and-null:
  *.[ch] refactoring: make use of the FREE_AND_NULL() macro
  coccinelle: make use of the "expression" FREE_AND_NULL() rule
  coccinelle: add a rule to make "expression" code use FREE_AND_NULL()
  coccinelle: make use of the "type" FREE_AND_NULL() rule
  coccinelle: add a rule to make "type" code use FREE_AND_NULL()
  git-compat-util: add a FREE_AND_NULL() wrapper around free(ptr); ptr = NULL

1 files changed, 2 insertions, 4 deletions

diff --git a/read-cache.c b/read-cache.c
index ad692e198..3c4354ee2 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -1895,8 +1895,7 @@ int discard_index(struct index_state *istate)
 	free_name_hash(istate);
 	cache_tree_free(&(istate->cache_tree));
 	istate->initialized = 0;
-	free(istate->cache);
-	istate->cache = NULL;
+	FREE_AND_NULL(istate->cache);
 	istate->cache_alloc = 0;
 	discard_split_index(istate);
 	free_untracked_cache(istate->untracked);
@@ -2610,8 +2609,7 @@ void *read_blob_data_from_index(const struct index_state *istate,
 
 void stat_validity_clear(struct stat_validity *sv)
 {
-	free(sv->sd);
-	sv->sd = NULL;
+	FREE_AND_NULL(sv->sd);
 }
 
 int stat_validity_check(struct stat_validity *sv, const char *path)