Fixed leak in debug message.

regs #1952 @20m

src/libknot/rrset.c

@@ -803,9 +803,12 @@ int knot_rrset_merge_no_dupl(void **r1, void **r2)
 		dbg_rrset("rrset: merge_no_dupl: NULL arguments.");
 		return KNOT_EBADARG;
 	}
-	
-	dbg_rrset_verb("rrset: merge_no_dupl: Merging %s.\n",
-	                 knot_dname_to_str(rrset1->owner));
+
+dbg_rrset_exec_verb(
+	char *name = knot_dname_to_str(rrset1->owner);
+	dbg_rrset_verb("rrset: merge_no_dupl: Merging %s.\n", name);
+	free(name);
+);
 
 	if ((knot_dname_compare(rrset1->owner, rrset2->owner) != 0)
 	    || rrset1->rclass != rrset2->rclass

src/libknot/util/debug.h

@@ -836,18 +836,22 @@ void knot_zone_contents_dump(knot_zone_contents_t *zone, char loaded_zone);
 #ifdef DEBUG_ENABLE_BRIEF
 #define dbg_rrset(msg...) log_msg(LOG_ZONE, LOG_DEBUG, msg)
 #define dbg_rrset_hex(data, len)  hex_log(LOG_ZONE, (data), (len))
+#define dbg_rrset_exec(cmds) do { cmds } while (0)
 #else
 #define dbg_rrset(msg...)
 #define dbg_rrset_hex(data, len)
+#define dbg_rrset_exec(cmds)
 #endif
 
 /* Verbose messages. */
 #ifdef DEBUG_ENABLE_VERBOSE
 #define dbg_rrset_verb(msg...) log_msg(LOG_ZONE, LOG_DEBUG, msg)
 #define dbg_rrset_hex_verb(data, len)  hex_log(LOG_ZONE, (data), (len))
+#define dbg_rrset_exec_verb(cmds) do { cmds } while (0)
 #else
 #define dbg_rrset_verb(msg...)
 #define dbg_rrset_hex_verb(data, len)
+#define dbg_rrset_exec_verb(cmds)
 #endif
 
 /* Detail messages. */