Merge pull request #1408 from Microsoft/ben/issue/723

document.isDirty appears to report false for dirty untitled document (fixes #723)

extensions/vscode-api-tests/src/workspace.test.ts

@@ -65,6 +65,7 @@ suite('workspace-namespace', () => {
 
 			return doc.save().then(() => {
 				assert.ok(closed === doc);
+				assert.ok(!doc.isDirty);
 				assert.ok(fs.existsSync(path));
 
 				d0.dispose();

src/vs/workbench/api/common/pluginHostDocuments.ts

@@ -203,6 +203,7 @@ export class BaseTextDocument implements vscode.TextDocument {
 	dispose(): void {
 		this._lines.length = 0;
 		this._textLines.length = 0;
+		this._isDirty = false;
 	}
 
 	get uri(): URI {