libpad: pad_free() accept and return NULLHEADmaster

Minor ergonimics change, originally I liked the idea of policing
programming errors like attempting to free a NULL pad.  But in
practice it's just more convenient to be free-like ignoring NULL
inputs, and while at it return a NULL pointer in case a reused
pointer needs to be NULL'd on free.

2 files changed, 10 insertions, 8 deletions

diff --git a/src/pad.c b/src/pad.c
index e7a1ad4..48186d3 100644
--- a/src/pad.c
+++ b/src/pad.c
@@ -196,18 +196,20 @@ void pad_reset(pad_t *pad)
 
 
 /* Free a pad and it's associated allocations. */
-void pad_free(pad_t *pad)
+pad_t * pad_free(pad_t *pad)
 {
-	chunk_t	*chunk, *_chunk;
+	if (pad) {
+		chunk_t	*chunk, *_chunk;
 
-	assert(pad);
+		pad_reset(pad);
 
-	pad_reset(pad);
+		list_for_each_entry_safe(chunk, _chunk, &pad->free_chunks, chunks)
+			free(chunk);
 
-	list_for_each_entry_safe(chunk, _chunk, &pad->free_chunks, chunks)
-		free(chunk);
+		free(pad);
+	}
 
-	free(pad);
+	return NULL;
 }
 
 
diff --git a/src/pad.h b/src/pad.h
index e9927e8..7a7a4dc 100644
--- a/src/pad.h
+++ b/src/pad.h
@@ -23,7 +23,7 @@ typedef struct pad_t pad_t;
 
 pad_t * pad_new(unsigned chunk_size, unsigned flags);
 void pad_reset(pad_t *pad);
-void pad_free(pad_t *pad);
+pad_t * pad_free(pad_t *pad);
 void * pad_get(pad_t *pad, unsigned size);
 void pad_put(void *mem);