Merge pull request #7268 from RyanCavanaugh/fix7063

Don't error on duplicate prototype property assignments

src/compiler/binder.ts

@@ -1466,7 +1466,8 @@ namespace ts {
             }
 
             // Declare the method/property
-            declareSymbol(funcSymbol.members, funcSymbol, leftSideOfAssignment, SymbolFlags.Property, SymbolFlags.PropertyExcludes);
+            // It's acceptable for multiple prototype property assignments of the same identifier to occur
+            declareSymbol(funcSymbol.members, funcSymbol, leftSideOfAssignment, SymbolFlags.Property, SymbolFlags.PropertyExcludes & ~SymbolFlags.Property);
         }
 
         function bindCallExpression(node: CallExpression) {

tests/cases/fourslash/jsDocClasses1.ts

@@ -0,0 +1,28 @@
+///<reference path="fourslash.ts" />
+
+// @allowNonTsExtensions: true
+// @Filename: Foo.js
+
+//// function fn() {
+//// 	this.foo = 10;
+//// }
+//// fn.prototype.foo = 14;
+//// var x = new fn();
+//// 
+//// function fn2() {
+//// 	this.foo = 10;
+//// 	this.foo = 10;
+//// }
+//// fn2.prototype.foo = 14;
+//// fn2.prototype.foo = 14;
+//// var y = new fn2();
+//// 
+//// function fn3() {
+//// 	this.foo = 10;
+//// }
+//// fn3.prototype.foo = 14;
+//// fn3.prototype.foo = 14;
+//// var z = new fn3();
+
+verify.numberOfErrorsInCurrentFile(0);
+