[[ Bug 16452 ]] Add error for global var shadowing a local var

livecodesebastien · livecodesebastien · commit d60520b15132 · 2015-11-19T18:00:28.000Z
diff --git a/docs/notes/bugfix-16452.md b/docs/notes/bugfix-16452.md
@@ -0,0 +1 @@
+# global variable shadowing local variable is not detected
diff --git a/engine/src/keywords.cpp b/engine/src/keywords.cpp
@@ -56,10 +56,41 @@ Parse_stat MCGlobal::parse(MCScriptPoint &sp)
 			(PE_GLOBAL_BADNAME, sp);
 			return PS_ERROR;
 		}
+
+        // SN-2015-11-19: [[ Bug 16452 ]] We need to check whether a local
+        // variable already exists at a script/handler level, to avoid shadowing
+        bool t_shadowing;
+        t_shadowing = false;
+
+        MCVarref* t_var;
+        t_var = NULL;
 		if (sp.gethandler() == NULL)
-			sp.gethlist()->newglobal(sp.gettoken_nameref());
+        {
+            sp.gethlist() -> findvar(sp.gettoken_nameref(), false, &t_var);
+            if (t_var == NULL || !MCexplicitvariables)
+                sp.gethlist()->newglobal(sp.gettoken_nameref());
+            else
+                t_shadowing = true;
+        }
 		else
-			sp.gethandler()->newglobal(sp.gettoken_nameref());
+        {
+            sp.gethandler()->findvar(sp.gettoken_nameref(), &t_var);
+            if (t_var == NULL || !MCexplicitvariables)
+                sp.gethandler()->newglobal(sp.gettoken_nameref());
+            else
+                t_shadowing = true;
+        }
+
+        // Clearup fetched var
+        delete t_var;
+
+        // In case we are shadowing a local variable, then we raise an error
+        if (t_shadowing)
+        {
+            MCperror -> add(PE_GLOBAL_SHADOW, sp);
+            return PS_ERROR;
+        }
+
 		switch (sp.next(type))
 		{
 		case PS_NORMAL:
diff --git a/engine/src/parseerrors.h b/engine/src/parseerrors.h
@@ -1674,6 +1674,11 @@ enum Parse_errors
 	// MM-2014-06-13: [[ Bug 12567 ]] New variant open socket <socket> with verification for host <host>
 	// {PE-0545} open: expected 'host'
 	PE_OPEN_NOHOST,	
+
+    // SN-2015-11-15: [[ Bug 165452 ]] New error, if a global variable shadows
+    // a local variable declared beforehand
+    // {PE-0546} global: shadowing a local variable
+    PE_GLOBAL_SHADOW,
 };
 
 extern const char *MCparsingerrors;

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+# global variable shadowing local variable is not detected`