From 36ac0c8f59c8488b017af132de2c71cbd911dd79 Mon Sep 17 00:00:00 2001
From: Cyrus Najmabadi <cyrusn@microsoft.com>
Date: Thu, 12 Mar 2015 10:16:28 -0700
Subject: [PATCH] Add additional asserts to ensure we don't create diagnostics
 with bogus positions.

---
 src/compiler/core.ts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index 1fb73c9069..463473497c 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -269,8 +269,12 @@ module ts {
 
     export function createFileDiagnostic(file: SourceFile, start: number, length: number, message: DiagnosticMessage, ...args: any[]): Diagnostic;
     export function createFileDiagnostic(file: SourceFile, start: number, length: number, message: DiagnosticMessage): Diagnostic {
+        var end = start + length;
+
         Debug.assert(start >= 0, "start must be non-negative, is " + start);
         Debug.assert(length >= 0, "length must be non-negative, is " + length);
+        Debug.assert(start <= file.text.length, `start must be within the bounds of the file. ${ start } > ${ file.text.length }`);
+        Debug.assert(end <= file.text.length, `end must be the bounds of the file. ${ end } > ${ file.text.length }`);
 
         var text = getLocaleSpecificMessage(message.key);