[21683] Fix crash when setting read-only props

livecodepanos · livecodepanos · commit 2cce35b4104c · 2018-11-15T15:12:02.000+02:00
diff --git a/engine/src/executionerrors.h b/engine/src/executionerrors.h
@@ -2777,6 +2777,9 @@ enum Exec_errors
     // {EE-0909} android permission: bad permission name
     EE_BAD_PERMISSION_NAME,
     
+    // {EE-0910} Property: value is not a data
+    EE_PROPERTY_NOTADATA
+    
 };
 
 extern const char *MCexecutionerrors;
diff --git a/engine/src/widget.cpp b/engine/src/widget.cpp
@@ -668,6 +668,28 @@ bool MCWidget::setcustomprop(MCExecContext& ctxt, MCNameRef p_set_name, MCNameRe
         !MCExtensionConvertFromScriptType(ctxt, t_set_type, InOut(t_value)))
     {
         CatchError(ctxt);
+        
+        Exec_errors t_error;
+        
+        MCResolvedTypeInfo t_resolved_type;
+        if (!MCTypeInfoResolve(t_set_type, t_resolved_type))
+            return false;
+        
+        if ( t_resolved_type . named_type == kMCBooleanTypeInfo)
+            t_error = EE_PROPERTY_NAB;
+        
+        else if (t_resolved_type . named_type == kMCNumberTypeInfo)
+            t_error = EE_PROPERTY_NAN;
+        else if (t_resolved_type . named_type == kMCStringTypeInfo)
+            t_error = EE_PROPERTY_NAS;
+        else if (t_resolved_type . named_type == kMCArrayTypeInfo || t_resolved_type . named_type == kMCProperListTypeInfo)
+            t_error = EE_PROPERTY_NOTANARRAY;
+        else if (t_resolved_type . named_type == kMCDataTypeInfo)
+            t_error = EE_PROPERTY_NOTADATA;
+        else
+            t_error = EE_PROPERTY_CANTSET;
+            
+        ctxt . LegacyThrow(t_error);
         return false;
     }
     
diff --git a/libscript/src/script-error.cpp b/libscript/src/script-error.cpp
@@ -397,3 +397,13 @@ MCScriptCreateErrorExpectedError(MCErrorRef& r_error)
 						  MCSTR("error propagated without error object"),
 						  nil);
 }
+
+bool MCScriptThrowAttemptToSetReadOnlyPropertyError(MCScriptInstanceRef p_instance, MCNameRef p_property)
+{
+    return MCErrorCreateAndThrow(kMCScriptCannotSetReadOnlyPropertyErrorTypeInfo,
+                                 "module",
+                                 p_instance -> module -> name,
+                                 "property",
+                                 p_property,
+                                 nil);
+}
diff --git a/libscript/src/script-instance.cpp b/libscript/src/script-instance.cpp
@@ -420,6 +420,10 @@ MCScriptSetPropertyInInstance(MCScriptInstanceRef self,
 	MCScriptDefinition *t_setter;
 	t_setter = t_property_def->setter != 0 ? self->module->definitions[t_property_def->setter - 1] : nil;
 	
+    // If there is no setter for the property then this is an error.
+    if (t_setter == nil)
+        return MCScriptThrowAttemptToSetReadOnlyPropertyError(self, p_property);
+    
 	/* LOAD CHECK */
 	__MCScriptAssert__(t_setter != nil,
 					   "property has no setter");
diff --git a/libscript/src/script-private.h b/libscript/src/script-private.h
@@ -606,6 +606,11 @@ MCScriptInternalHandlerQuery(MCHandlerRef handler,
 bool
 MCScriptThrowPropertyNotFoundError(MCScriptInstanceRef instance,
 								   MCNameRef property);
+
+bool
+MCScriptThrowAttemptToSetReadOnlyPropertyError(MCScriptInstanceRef instance,
+                                   MCNameRef property);
+
 bool
 MCScriptThrowHandlerNotFoundError(MCScriptInstanceRef instance,
 								  MCNameRef handler);
