[PATCH] refactor various if (x) FREE_AND_NULL(x) to just FREE_AND_NULL(x)

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Change the few conditional uses of FREE_AND_NULL(x) to be
unconditional. As noted in the standard[1] free(NULL) is perfectly
valid, so we might as well leave this check up to the C library.

1. http://pubs.opengroup.org/onlinepubs/9699919799/functions/free.html

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---

Let's do the opposite of this instead.

 blame.c     | 4 +---
 branch.c    | 4 +---
 http.c      | 4 +---
 tree-diff.c | 4 +---
 4 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/blame.c b/blame.c
index 58a7036847..b22a95de7b 100644
--- a/blame.c
+++ b/blame.c
@@ -334,9 +334,7 @@ static void fill_origin_blob(struct diff_options *opt,
 
 static void drop_origin_blob(struct blame_origin *o)
 {
-	if (o->file.ptr) {
-		FREE_AND_NULL(o->file.ptr);
-	}
+	FREE_AND_NULL(o->file.ptr);
 }
 
 /*
diff --git a/branch.c b/branch.c
index ecd710d730..776f55fc66 100644
--- a/branch.c
+++ b/branch.c
@@ -25,9 +25,7 @@ static int find_tracked_branch(struct remote *remote, void *priv)
 			tracking->remote = remote->name;
 		} else {
 			free(tracking->spec.src);
-			if (tracking->src) {
-				FREE_AND_NULL(tracking->src);
-			}
+			FREE_AND_NULL(tracking->src);
 		}
 		tracking->spec.src = NULL;
 	}
diff --git a/http.c b/http.c
index b4bfbceaeb..4162860ee3 100644
--- a/http.c
+++ b/http.c
@@ -2418,9 +2418,7 @@ void release_http_object_request(struct http_object_request *freq)
 		close(freq->localfile);
 		freq->localfile = -1;
 	}
-	if (freq->url != NULL) {
-		FREE_AND_NULL(freq->url);
-	}
+	FREE_AND_NULL(freq->url);
 	if (freq->slot != NULL) {
 		freq->slot->callback_func = NULL;
 		freq->slot->callback_data = NULL;
diff --git a/tree-diff.c b/tree-diff.c
index fe2e466ac1..553bc0e63a 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -557,9 +557,7 @@ struct combine_diff_path *diff_tree_paths(
 	 * free pre-allocated last element, if any
 	 * (see path_appendnew() for details about why)
 	 */
-	if (p->next) {
-		FREE_AND_NULL(p->next);
-	}
+	FREE_AND_NULL(p->next);
 
 	return p;
 }
-- 
2.18.0.865.gffc8e1a3cd6