backslash escapes backslash, #16212

src/vs/editor/contrib/snippet/common/snippetParser.ts

@@ -373,7 +373,7 @@ export class SnippetParser {
 			if (// Internal style
 				(this._enableInternal && (this._accept(TokenType.CurlyOpen) || this._accept(TokenType.CurlyClose) || this._accept(TokenType.Backslash)))
 				// TextMate style
-				|| (this._enableTextMate && (this._accept(TokenType.Dollar) || this._accept(TokenType.CurlyClose)))
+				|| (this._enableTextMate && (this._accept(TokenType.Dollar) || this._accept(TokenType.CurlyClose) || this._accept(TokenType.Backslash)))
 			) {
 				// just consume them
 			}

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

@@ -281,4 +281,9 @@ suite('SnippetParser', () => {
 		assert.equal((<Text>(<Placeholder>p2).defaultValue[0]), 'err');
 
 	});
+
+	test('backspace esapce in TM only, #16212', () => {
+		const actual = new SnippetParser(true, false).escape('Foo \\\\${abc}bar');
+		assert.equal(actual, 'Foo \\bar');
+	});
 });