From 78d1bd1570785df0099e0cf6ac4565556b4f82fc Mon Sep 17 00:00:00 2001
From: lin onetwo <linonetwo012@gmail.com>
Date: Wed, 12 Jun 2024 21:12:27 +0800
Subject: [PATCH] fix: ignore self-referential transclusion

---
 core/modules/indexers/back-indexer.js          |  2 +-
 core/modules/wiki.js                           | 10 ++++++----
 .../tiddlers/tests/test-backtranscludes.js     | 18 +++++++++++++++++-
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/core/modules/indexers/back-indexer.js b/core/modules/indexers/back-indexer.js
index b9daf3328..77b51b819 100644
--- a/core/modules/indexers/back-indexer.js
+++ b/core/modules/indexers/back-indexer.js
@@ -75,7 +75,7 @@ BackSubIndexer.prototype._getTarget = function(tiddler) {
 	}
 	var parser = this.wiki.parseText(tiddler.fields.type, tiddler.fields.text, {});
 	if(parser) {
-		return this.wiki[this.extractor](parser.tree);
+		return this.wiki[this.extractor](parser.tree, tiddler.fields.title);
 	}
 	return [];
 }
diff --git a/core/modules/wiki.js b/core/modules/wiki.js
index 2850dec5f..44e09cfde 100755
--- a/core/modules/wiki.js
+++ b/core/modules/wiki.js
@@ -551,9 +551,9 @@ exports.getTiddlerBacklinks = function(targetTitle) {
 
 
 /*
-Return an array of tiddler titles that are directly transcluded within the given parse tree
+Return an array of tiddler titles that are directly transcluded within the given parse tree. `title` is the tiddler being parsed, we will ignore its self-referential transclusions, only return
  */
-exports.extractTranscludes = function(parseTreeRoot) {
+exports.extractTranscludes = function(parseTreeRoot, title) {
 	// Count up the transcludes
 	var transcludes = [],
 		checkParseTree = function(parseTree, parentNode) {
@@ -567,7 +567,8 @@ exports.extractTranscludes = function(parseTreeRoot) {
 					} else {
 						value = parseTreeNode.attributes.$tiddler.value;
 					}
-					if(transcludes.indexOf(value) === -1 && value !== undefined) {
+					// ignore empty value (like `{{!!field}}`), and deduplicate
+					if(value && transcludes.indexOf(value) === -1 && value !== title) {
 						transcludes.push(value);
 					}
 				}
@@ -591,7 +592,8 @@ exports.getTiddlerTranscludes = function(title) {
 		// Parse the tiddler
 		var parser = self.parseTiddler(title);
 		if(parser) {
-			return self.extractTranscludes(parser.tree);
+			// this will ignore self-referential transclusions from `title`
+			return self.extractTranscludes(parser.tree, title);
 		}
 		return [];
 	});
diff --git a/editions/test/tiddlers/tests/test-backtranscludes.js b/editions/test/tiddlers/tests/test-backtranscludes.js
index fe6d09706..f0ecd26f0 100644
--- a/editions/test/tiddlers/tests/test-backtranscludes.js
+++ b/editions/test/tiddlers/tests/test-backtranscludes.js
@@ -187,7 +187,7 @@ describe('Backtranscludes and transclude filter tests', function() {
 
 		wiki.addTiddler({
 			title: 'TestOutgoing',
-			text: "{{!!created}}\n\nA transclude to {{!!title}}"});
+			text: "{{!!created}}\n\nAn implicit self-referential transclude to <$transclude $field='created'/> and <$transclude field='created'/>"});
 
 		it('should have no transclude', function() {
 			expect(wiki.filterTiddlers('TestOutgoing +[transcludes[]]').join(',')).toBe('');
@@ -198,6 +198,22 @@ describe('Backtranscludes and transclude filter tests', function() {
 		});
 	});
 
+	describe('Explicit self transclusion', function() {
+		var wiki = new $tw.Wiki();
+
+		wiki.addTiddler({
+			title: 'TestOutgoing',
+			text: "{{TestOutgoing!!created}}\n\n<$transclude $tiddler='TestOutgoing' $field='created'/> and <$transclude tiddler='TestOutgoing' field='created'/>"});
+
+			it('should have no transclude', function() {
+			expect(wiki.filterTiddlers('TestOutgoing +[transcludes[]]').join(',')).toBe('');
+		});
+
+		it('should have no back transcludes', function() {
+			expect(wiki.filterTiddlers('TestOutgoing +[backtranscludes[]]').join(',')).toBe('');
+		});
+	});
+
 	describe('recognize soft transclusion defined by widget', function() {
 		var wiki = new $tw.Wiki();