Harden against trees without parent pointers for emitting literals; fix lookahead in text for numeric literal indicators.

Author: DanielRosenwasser

src/compiler/emitter.ts

@@ -2178,15 +2178,17 @@ module ts {
                 }
             }
 
-            function isBinaryOrOctalIntegerLiteral(text: string): boolean {
-                if (text.length <= 0) {
-                    return false;
-                }
-
-                if (text.charCodeAt(1) === CharacterCodes.B || text.charCodeAt(1) === CharacterCodes.b ||
-                    text.charCodeAt(1) === CharacterCodes.O || text.charCodeAt(1) === CharacterCodes.o) {
-                    return true;
+            function isBinaryOrOctalIntegerLiteral(node: LiteralExpression, text: string): boolean {
+                if (node.kind === SyntaxKind.NumericLiteral && text.length > 1) {
+                    switch (text.charCodeAt(1)) {
+                        case CharacterCodes.b:
+                        case CharacterCodes.B:
+                        case CharacterCodes.o:
+                        case CharacterCodes.O:
+                            return true;
+                    }
                 }
+                
                 return false;
             }
 
@@ -2195,13 +2197,15 @@ module ts {
                     ? getDoubleQuotedStringTextOfLiteral(node)
                     : node.parent
                         ? getSourceTextOfNodeFromSourceFile(currentSourceFile, node)
-                        : node.text; // TODO(drosen): Is this correct?
+                        : node.kind === SyntaxKind.NumericLiteral
+                            ? node.text
+                            : getDoubleQuotedStringTextOfLiteral(node);
 
                 if (compilerOptions.sourceMap && (node.kind === SyntaxKind.StringLiteral || isTemplateLiteralKind(node.kind))) {
                     writer.writeLiteral(text);
                 }
-                // For version below ES6, emit binary integer literal and octal integer literal in canonical form
-                else if (languageVersion < ScriptTarget.ES6 && node.kind === SyntaxKind.NumericLiteral && isBinaryOrOctalIntegerLiteral(text)) {
+                // For versions below ES6, emit binary & octal literals in their canonical decimal form.
+                else if (languageVersion < ScriptTarget.ES6 && isBinaryOrOctalIntegerLiteral(node, text)) {
                     write(node.text);
                 }
                 else {