From: Florian Forster <octo@collectd.org>
Date: Wed, 13 Dec 2023 14:35:23 +0000 (+0100)
Subject: Change the semantic of `label_set_clone`.
X-Git-Tag: 6.0.0-rc0~37^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=826e457cb9f80ae4fa20d0563acf6ef22b1600de;p=thirdparty%2Fcollectd.git

Change the semantic of `label_set_clone`.

It checks to ensure that `dest` is empty and returns `EINVAL` otherwise.
---

diff --git a/src/daemon/metric.c b/src/daemon/metric.c
index 55edc7a7d..d273863d7 100644
--- a/src/daemon/metric.c
+++ b/src/daemon/metric.c
@@ -214,6 +214,10 @@ void label_set_reset(label_set_t *labels) {
 }
 
 int label_set_clone(label_set_t *dest, label_set_t src) {
+  if (dest == NULL || dest->num != 0) {
+    return EINVAL;
+  }
+
   if (src.num == 0) {
     return 0;
   }
diff --git a/src/daemon/metric.h b/src/daemon/metric.h
index a91f596f1..35fdf6dad 100644
--- a/src/daemon/metric.h
+++ b/src/daemon/metric.h
@@ -70,9 +70,9 @@ typedef struct {
   size_t num;
 } label_set_t;
 
-/* label_set_clone copies all the labels in src into dest. If dest contains
- * any labels prior to calling label_set_clone, the associated memory is
- * leaked. */
+/* label_set_clone copies all the labels in src into dest. dest must be an empty
+ * label set, i.e. it must not contain any prior labels, otherwise EINVAL is
+ * returned. */
 int label_set_clone(label_set_t *dest, label_set_t src);
 
 /* label_set_add adds a label to the label set. If a label with name already