[[ Bug 21926 ]] Fix memory leak when using message box put command

runrevmark · runrevmark · commit e08c3dc851f3 · 2019-03-26T11:36:16.000Z
This patch fixes a memory leak which occurs when using the message
box targetting put command variant (i.e. put or put into msg). The
leak was occurring due to a failure to delete the handler name
and line number arguments (in the form of MCParmaeter instances). To
fix this, the MCParameter instances are now allocated on the stack
rather than on the heap.
diff --git a/docs/notes/bugfix-21926.md b/docs/notes/bugfix-21926.md
@@ -0,0 +1 @@
+# Fix memory leak when using put commands which target the message box
diff --git a/engine/src/debug.cpp b/engine/src/debug.cpp
@@ -145,16 +145,15 @@ void MCB_setmsg(MCExecContext &ctxt, MCStringRef p_string)
 
         MCAutoStringRef t_handler;
         t_handler = MCNameGetString(ctxt.GetHandler()->getname());
-        MCParameter *t_handler_parameter = new (nothrow) MCParameter;
-        t_handler_parameter -> setvalueref_argument(*t_handler);
+        MCParameter t_handler_parameter;
+        t_handler_parameter.setvalueref_argument(*t_handler);
         
         MCAutoNumberRef t_line;
-        MCParameter *t_line_parameter;
+        MCParameter t_line_parameter;
         if (MCNumberCreateWithUnsignedInteger(ctxt.GetLine(), &t_line))
         {
-            t_line_parameter = new (nothrow) MCParameter;
-            t_line_parameter -> setvalueref_argument(*t_line);
-            t_handler_parameter -> setnext(t_line_parameter);
+            t_line_parameter.setvalueref_argument(*t_line);
+            t_handler_parameter.setnext(&t_line_parameter);
         }
         
         bool t_added = false;
@@ -164,7 +163,7 @@ void MCB_setmsg(MCExecContext &ctxt, MCStringRef p_string)
             t_added = true;
         }
         
-        t_stat = t_target -> message(MCM_msgchanged, t_handler_parameter, True, True, False);
+        t_stat = t_target -> message(MCM_msgchanged, &t_handler_parameter, True, True, False);
         
         if (t_added)
             MCnexecutioncontexts--;

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+# Fix memory leak when using put commands which target the message box`