Debian bug 534835: Check some SpiderMonkey return values

Perhaps because of bug 981, if one opened hundreds of pages with
elinks --remote openURL(...), then ELinks 0.11.4 could crash with a
SIGSEGV in JS_InitClass called from spidermonkey_get_interpreter.
SpiderMonkey ran out of memory and began returning NULL and JS_FALSE
but ELinks didn't notice them and pressed on.  Add some checks to
avoid the crash, although the underlying out-of-memory error remains.

NEWS

@@ -11,6 +11,8 @@ ELinks 0.12pre4.GIT now:
 To be released as 0.12pre5, 0.12rc1, or even 0.12.0.  This branch also
 includes the changes listed under ``ELinks 0.11.6.GIT now'' below.
 
+* Debian bug 534835: Check the return values of some SpiderMonkey
+  functions, to avoid crashes if out of memory.
 * bug 1080: Support ``--dump-color-mode'' with ``--dump-charset UTF-8''.
 * minor bug 1017: To work around HTTP server bugs, disable
   protocol.http.compression by default, until ELinks can report

src/ecmascript/spidermonkey.c

@@ -174,57 +174,70 @@ spidermonkey_get_interpreter(struct ecmascript_interpreter *interpreter)
 	JS_SetErrorReporter(ctx, error_reporter);
 
 	window_obj = JS_NewObject(ctx, (JSClass *) &window_class, NULL, NULL);
-	if (!window_obj) {
+	if (!window_obj) goto release_and_fail;
-		spidermonkey_put_interpreter(interpreter);
+	if (!JS_InitStandardClasses(ctx, window_obj)) goto release_and_fail;
-		return NULL;
+	if (!JS_DefineProperties(ctx, window_obj, (JSPropertySpec *) window_props))
-	}
+		goto release_and_fail;
-	JS_InitStandardClasses(ctx, window_obj);
+	if (!spidermonkey_DefineFunctions(ctx, window_obj, window_funcs))
-	JS_DefineProperties(ctx, window_obj, (JSPropertySpec *) window_props);
+		goto release_and_fail;
-	spidermonkey_DefineFunctions(ctx, window_obj, window_funcs);
+	if (!JS_SetPrivate(ctx, window_obj, interpreter->vs)) /* to @window_class */
-	JS_SetPrivate(ctx, window_obj, interpreter->vs); /* to @window_class */
+		goto release_and_fail;
 
 	document_obj = spidermonkey_InitClass(ctx, window_obj, NULL,
 					      (JSClass *) &document_class, NULL, 0,
 					      (JSPropertySpec *) document_props,
 					      document_funcs,
 					      NULL, NULL);
+	if (!document_obj) goto release_and_fail;
 
 	forms_obj = spidermonkey_InitClass(ctx, document_obj, NULL,
 					   (JSClass *) &forms_class, NULL, 0,
 					   (JSPropertySpec *) forms_props,
 					   forms_funcs,
 					   NULL, NULL);
+	if (!forms_obj) goto release_and_fail;
 
 	history_obj = spidermonkey_InitClass(ctx, window_obj, NULL,
 					     (JSClass *) &history_class, NULL, 0,
 					     (JSPropertySpec *) NULL,
 					     history_funcs,
 					     NULL, NULL);
+	if (!history_obj) goto release_and_fail;
 
 	location_obj = spidermonkey_InitClass(ctx, window_obj, NULL,
 					      (JSClass *) &location_class, NULL, 0,
 					      (JSPropertySpec *) location_props,
 					      location_funcs,
 					      NULL, NULL);
+	if (!location_obj) goto release_and_fail;
 
 	menubar_obj = JS_InitClass(ctx, window_obj, NULL,
 				   (JSClass *) &menubar_class, NULL, 0,
 				   (JSPropertySpec *) unibar_props, NULL,
 				   NULL, NULL);
-	JS_SetPrivate(ctx, menubar_obj, "t"); /* to @menubar_class */
+	if (!menubar_obj) goto release_and_fail;
+	if (!JS_SetPrivate(ctx, menubar_obj, "t")) /* to @menubar_class */
+		goto release_and_fail;
 
 	statusbar_obj = JS_InitClass(ctx, window_obj, NULL,
 				     (JSClass *) &statusbar_class, NULL, 0,
 				     (JSPropertySpec *) unibar_props, NULL,
 				     NULL, NULL);
-	JS_SetPrivate(ctx, statusbar_obj, "s"); /* to @statusbar_class */
+	if (!statusbar_obj) goto release_and_fail;
+	if (!JS_SetPrivate(ctx, statusbar_obj, "s")) /* to @statusbar_class */
+		goto release_and_fail;
 
 	navigator_obj = JS_InitClass(ctx, window_obj, NULL,
 				     (JSClass *) &navigator_class, NULL, 0,
 				     (JSPropertySpec *) navigator_props, NULL,
 				     NULL, NULL);
+	if (!navigator_obj) goto release_and_fail;
 
 	return ctx;
+
+release_and_fail:
+	spidermonkey_put_interpreter(interpreter);
+	return NULL;
 }
 
 void

src/scripting/smjs/elinks_object.c

@@ -134,16 +134,19 @@ smjs_get_elinks_object(void)
 	jsobj = spidermonkey_InitClass(smjs_ctx, smjs_global_object, NULL,
 				       (JSClass *) &elinks_class, NULL, 0, NULL,
 				       elinks_funcs, NULL, NULL);
+	if (!jsobj) return NULL;
 
-	JS_DefineProperty(smjs_ctx, jsobj, "location", JSVAL_NULL,
+	if (!JS_DefineProperty(smjs_ctx, jsobj, "location", JSVAL_NULL,
-	                  elinks_get_location, elinks_set_location,
+			       elinks_get_location, elinks_set_location,
-	                  JSPROP_ENUMERATE | JSPROP_PERMANENT);
+			       JSPROP_ENUMERATE | JSPROP_PERMANENT))
+		return NULL;
 
-	JS_DefineProperty(smjs_ctx, jsobj, "home", JSVAL_NULL,
+	if (!JS_DefineProperty(smjs_ctx, jsobj, "home", JSVAL_NULL,
-	                  elinks_get_home, JS_PropertyStub,
+			       elinks_get_home, JS_PropertyStub,
-	                  JSPROP_ENUMERATE
+			       JSPROP_ENUMERATE
-	                   | JSPROP_PERMANENT
+			       | JSPROP_PERMANENT
-	                   | JSPROP_READONLY);
+			       | JSPROP_READONLY))
+		return NULL;
 
 	return jsobj;
 }
@@ -151,7 +154,7 @@ smjs_get_elinks_object(void)
 void
 smjs_init_elinks_object(void)
 {
-	smjs_elinks_object = smjs_get_elinks_object();
+	smjs_elinks_object = smjs_get_elinks_object(); /* TODO: check NULL */
 
 	smjs_init_action_interface();
 	smjs_init_bookmarks_interface();