(enh) disallow compiling into an existing named module

Author: joshgoebel

deps/wren/src/optional/wren_opt_meta.c

@@ -16,6 +16,10 @@ void metaCompile(WrenVM* vm)
   const char* module;
   if (wrenGetSlotType(vm, 2) != WREN_TYPE_NULL) {
     module = wrenGetSlotString(vm, 2);
+    if (wrenHasModule(vm,module)) {
+      wrenSetSlotString(vm, 0, "Security: Cannot compile into an existing named module.");
+      wrenAbortFiber(vm, 0);
+    }
   } else {
     // TODO: Allow passing in module?
     // Look up the module surrounding the callsite. This is brittle. The -2 walks

deps/wren/src/optional/wren_opt_meta.wren

@@ -7,6 +7,7 @@ class Meta {
     Fiber.abort("Could not find a module named '%(module)'.")
   }
 
+  static eval(source) { eval(source, null) }
   static eval(source, module) {
     if (!(source is String)) Fiber.abort("Source code must be a string.")
 

deps/wren/src/optional/wren_opt_meta.wren.inc

@@ -11,6 +11,7 @@ static const char* metaModuleSource =
 "    Fiber.abort(\"Could not find a module named '%(module)'.\")\n"
 "  }\n"
 "\n"
+"  static eval(source) { eval(source, null) }\n"
 "  static eval(source, module) {\n"
 "    if (!(source is String)) Fiber.abort(\"Source code must be a string.\")\n"
 "\n"