Return FluentNone from Patterns with too long placeables

Author: stasm

fluent/src/resolver.js

@@ -289,11 +289,12 @@ export function resolveComplexPattern(scope, ptn) {
           `(${part.length}, max allowed is ${MAX_PLACEABLE_LENGTH})`
         )
       );
-      result.push(part.slice(MAX_PLACEABLE_LENGTH));
-    } else {
-      result.push(part);
+      scope.dirty.delete(ptn);
+      return new FluentNone();
     }
 
+    result.push(part);
+
     if (useIsolating) {
       result.push(PDI);
     }

fluent/test/bomb_test.js

@@ -13,6 +13,8 @@ suite('Reference bombs', function() {
   });
 
   suite('Billion Laughs', function(){
+    this.timeout(10000);
+
     suiteSetup(function() {
       bundle = new FluentBundle('en-US', { useIsolating: false });
       bundle.addMessages(ftl`
@@ -30,13 +32,14 @@ suite('Reference bombs', function() {
         `);
     });
 
-    // XXX Protect the FTL Resolver against the billion laughs attack
-    // https://bugzil.la/1307126
-    test.skip('does not expand all placeables', function() {
+    test('does not expand all placeables', function() {
       const msg = bundle.getMessage('lolz');
       const val = bundle.formatPattern(msg.value, args, errs);
-      assert.strictEqual(val, '???');
-      assert.strictEqual(errs.length, 1);
+      assert.strictEqual(
+        val,
+        '{???} {???} {???} {???} {???} {???} {???} {???} {???} {???}'
+      );
+      assert.strictEqual(errs.length, 10010);
     });
   });
 });