fix an issue with variable names and snippet rewriting

src/vs/editor/contrib/snippet/test/browser/snippetParser.test.ts

@@ -197,6 +197,8 @@ suite('SnippetParser', () => {
 		assertTextAndMarker('$123', '', Placeholder);
 		assertTextAndMarker('$farboo', '', Variable);
 		assertTextAndMarker('$far12boo', '', Variable);
+		assertTextAndMarker('000_${far}_000', '000__000', Text, Variable, Text);
+		assertTextAndMarker('FFF_${TM_SELECTED_TEXT}_FFF$0', 'FFF__FFF', Text, Variable, Text, Placeholder);
 	});
 
 	test('Parser, variables/placeholder with defaults', () => {

src/vs/workbench/parts/emmet/electron-browser/editorAccessor.ts

@@ -155,7 +155,7 @@ export class EditorAccessor implements emmet.Editor {
 				if (marker.children.length > 0) {
 					return `\${${marker.name}:${marker.children.map(toSnippetString).join('')}}`;
 				} else {
-					return `\$${marker.name}`;
+					return `\${${marker.name}}`;
 				}
 			} else {
 				throw new Error('unexpected marker: ' + marker);

src/vs/workbench/parts/snippets/electron-browser/TMSnippets.ts

@@ -193,7 +193,7 @@ function _rewriteBogousVariables(snippet: ISnippet): boolean {
 			} else if (marker.children.length > 0) {
 				return `\${${marker.name}:${marker.children.map(fixBogousVariables).join('')}}`;
 			} else {
-				return `\$${marker.name}`;
+				return `\${${marker.name}}`;
 			}
 		} else {
 			throw new Error('unexpected marker: ' + marker);