Merge pull request #6709 from RyanCavanaugh/fix6662

Don't crash when return type jsdoc tag is malformed

src/compiler/checker.ts

@@ -10380,9 +10380,11 @@ namespace ts {
 
         function getReturnTypeFromJSDocComment(func: SignatureDeclaration | FunctionDeclaration): Type {
             const returnTag = getJSDocReturnTag(func);
-            if (returnTag) {
+            if (returnTag && returnTag.typeExpression) {
                 return getTypeFromTypeNode(returnTag.typeExpression.type);
             }
+
+            return undefined;
         }
 
         function createPromiseType(promisedType: Type): Type {

tests/cases/fourslash/getJavaScriptQuickInfo7.ts

@@ -0,0 +1,20 @@
+/// <reference path="fourslash.ts" />
+
+// @allowNonTsExtensions: true
+// @Filename: file.js
+//// /**
+////  * This is a very cool function that is very nice.
+////  * @returns something
+////  * @param p anotherthing
+////  */
+//// function a1(p) {
+//// 	try {
+//// 		throw new Error('x');
+//// 	} catch (x) { x--; }
+//// 	return 23;
+//// }
+//// 
+//// x - /**/a1()
+
+goTo.marker();
+verify.quickInfoExists();