*: Convert list_delete(struct list *) to ** to allow nulling

Convert the list_delete(struct list *) function to use
struct list **.  This is to allow the list pointer to be nulled.

I keep running into uses of this list_delete function where we
forget to set the returned pointer to NULL and attempt to use
it and then experience a crash, usually after the developer
has long since left the building.

Let's make the api explicit in it setting the list pointer
to null.

Cynical Prediction:  This code will expose a attempt
to use the NULL'ed list pointer in some obscure bit
of code.

Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/lib/command_match.c b/lib/command_match.c
index 6384abe5ce..c60373f910 100644
--- a/lib/command_match.c
+++ b/lib/command_match.c
@@ -333,7 +333,7 @@ static enum matcher_rv command_match_r(struct graph_node *start, vector vline,
 		status = MATCHER_INCOMPLETE;
 
 	// cleanup
-	list_delete(next);
+	list_delete_and_null(&next);
 
 	return status;
 }
@@ -366,7 +366,7 @@ enum matcher_rv command_complete(struct graph *graph, vector vline,
 
 	unsigned int idx;
 	for (idx = 0; idx < vector_active(vline) && next->count > 0; idx++) {
-		list_delete(current);
+		list_delete_and_null(&current);
 		current = next;
 		next = list_new();
 		next->del = stack_del;
@@ -457,8 +457,8 @@ enum matcher_rv command_complete(struct graph *graph, vector vline,
 		}
 	}
 
-	list_delete(current);
-	list_delete(next);
+	list_delete_and_null(&current);
+	list_delete_and_null(&next);
 
 	return mrv;
 }
@@ -648,7 +648,7 @@ static void del_arglist(struct list *list)
 	list_delete_node(list, tail);
 
 	// delete the rest of the list as usual
-	list_delete(list);
+	list_delete_and_null(&list);
 }
 
 /*---------- token level matching functions ----------*/