Fix: limit macro call parser to need >> to work, prevent > in regex (#9813)

* fix: limit macro call parser to need >> to work, prevent > in regex

* test: add malformed macro parameter regression coverage

The parser fix on this branch only changes parseMacroParameterAsAttribute() when an unquoted value starts with <<, so the previous broader parser tests did not prove the regression. Add a focused structural test that fails without the guard and passes with it.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

* Revert "fix: limit macro call parser to need >> to work, prevent > in regex"

This reverts commit f96b062902.

* lint: test

* Reapply "fix: limit macro call parser to need >> to work, prevent > in regex"

This reverts commit 075f7cc282.

---------

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

core/modules/parsers/parseutils.js

@@ -327,7 +327,7 @@ exports.parseMacroParameterAsAttribute = function(source,pos) {
 	// Define our regexps
 	var reAttributeName = /([^\/\s>"'`=:]+)/y,
 		reStrictIdentifier = /^[A-Za-z0-9\-_]+$/,
-		reUnquotedAttribute = /((?:(?:>(?!>))|[^\s>"'])+)/y,
+		reUnquotedAttribute = /(?!<<)((?:(?:>(?!>))|[^\s>"'])+)/y,
 		reFilteredValue = /\{\{\{([\S\s]+?)\}\}\}/y,
 		reIndirectValue = /\{\{([^\}]+)\}\}/y,
 		reSubstitutedValue = /(?:```([\s\S]*?)```|`([^`]|[\S\s]*?)`)/y;

editions/test/tiddlers/tests/test-wikitext-parser.js

@@ -468,5 +468,9 @@ describe("WikiText parser tests", function() {
 
 		expect(parse(wikitext)).toEqual(expectedParseTree);
 	});
-});
 
+	it("should reject unquoted macro parameter values that start with <<", function() {
+		var attribute = $tw.utils.parseMacroParameterAsAttribute("d=<<d> />",0);
+		expect(attribute).toBeNull();
+	});
+});