From 175dba49777a4c63ff061289b8e1ebab2651d2e0 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Fri, 18 Jul 2014 17:04:06 -0700
Subject: [PATCH] Ensuring local module names are unique in emit. Fixes #41 and
 #42.

---
 src/compiler/binder.ts  |  1 +
 src/compiler/checker.ts | 43 +++++++++++++++++++++++++++++++++++++++++
 src/compiler/types.ts   |  2 +-
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index ec67b496db6..691965b0ad7 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -33,6 +33,7 @@ module ts {
         var container: Declaration;
         var lastContainer: Declaration;
         var symbolCount = 0;
+        var lastLocals: Declaration;
         var Symbol = objectAllocator.getSymbolConstructor();
 
         if (!file.locals) {
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 6541a3641d8..8cb72980e74 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -6049,6 +6049,49 @@ module ts {
             Debug.fail("getLocalNameForSymbol failed");
         }
 
+        function isNodeParentedBy(node: Node, parent: Node): boolean {
+            while (node) {
+                if (node === parent) return true;
+                node = node.parent;
+            }
+            return false;
+        }
+
+        function isUniqueLocalName(name: string, container: Node): boolean {
+            name = escapeIdentifier(name);
+            if (container.locals) {
+                for (var node = container; isNodeParentedBy(node, container); node = node.nextLocals) {
+                    if (hasProperty(node.locals, name) && node.locals[name].flags & (SymbolFlags.Value | SymbolFlags.ExportValue)) {
+                        return false;
+                    }
+                }
+            }
+            return true;
+        }
+
+        function getLocalNameOfContainer(container: Declaration): string {
+            var links = getNodeLinks(container);
+            if (!links.localModuleName) {
+                var name = container.name.text ? unescapeIdentifier(container.name.text) : "M";
+                while (!isUniqueLocalName(name, container)) {
+                    name = "_" + name;
+                }
+                links.localModuleName = name;
+            }
+            return links.localModuleName;
+        }
+
+        function getLocalNameForSymbol(symbol: Symbol, location: Node): string {
+            var node = location;
+            while (node) {
+                if ((node.kind === SyntaxKind.ModuleDeclaration || node.kind === SyntaxKind.EnumDeclaration) && getSymbolOfNode(node) === symbol) {
+                    return getLocalNameOfContainer(node);
+                }
+                node = node.parent;
+            }
+            Debug.fail("getLocalNameForSymbol failed");
+        }
+
         function getExpressionNamePrefix(node: Identifier): string {
             var symbol = getNodeLinks(node).resolvedSymbol;
             if (symbol) {
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 5decadcfe17..3820920dffa 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -691,7 +691,7 @@ module ts {
 
         ExportHasLocal = Function | Class | Enum | ValueModule,
 
-        HasLocals  = Function | Module | Method | Constructor | Accessor | Signature,
+        HasLocals  = Function | Enum | Module | Method | Constructor | Accessor | Signature,
         HasExports = Class | Enum | Module,
         HasMembers = Class | Interface | TypeLiteral | ObjectLiteral,