From 844564180f466f2e1545d579d19c38e7f8836fd1 Mon Sep 17 00:00:00 2001
From: yaisog <m@rcuswinter.de>
Date: Tue, 20 Jan 2026 11:24:56 +0100
Subject: [PATCH]  Fix LetWidget to always set all staged variables on first
 render (#9494)

* Always set all staged variables on first render

* Add changenote
---
 core/modules/widgets/let.js                            |  5 ++---
 editions/tw5.com/tiddlers/releasenotes/5.4.0/#9494.tid | 10 ++++++++++
 2 files changed, 12 insertions(+), 3 deletions(-)
 create mode 100644 editions/tw5.com/tiddlers/releasenotes/5.4.0/#9494.tid

diff --git a/core/modules/widgets/let.js b/core/modules/widgets/let.js
index b09c67e91d..6ede8b1dd3 100644
--- a/core/modules/widgets/let.js
+++ b/core/modules/widgets/let.js
@@ -7,7 +7,6 @@ This widget allows defining multiple variables at once, while allowing
 the later variables to depend upon the earlier ones.
 
 ```
-\define helloworld() Hello world!
 <$let currentTiddler="target" value={{!!value}} currentTiddler="different">
   {{!!value}} will be different from <<value>>
 </$let>
@@ -56,7 +55,7 @@ LetWidget.prototype.computeAttributes = function() {
 	});
 	// Run through again, setting variables and looking for differences
 	$tw.utils.each(this.currentValueFor,function(value,name) {
-		if(!$tw.utils.isArrayEqual(self.attributes[name],value)) {
+		if(self.attributes[name] === undefined || !$tw.utils.isArrayEqual(self.attributes[name],value)) {
 			self.attributes[name] = value;
 			self.setVariable(name,value);
 			changedAttributes[name] = true;
@@ -68,7 +67,7 @@ LetWidget.prototype.computeAttributes = function() {
 LetWidget.prototype.getVariableInfo = function(name,options) {
 	// Special handling: If this variable exists in this very $let, we can
 	// use it, but only if it's been staged.
-	if ($tw.utils.hop(this.currentValueFor,name)) {
+	if($tw.utils.hop(this.currentValueFor,name)) {
 		var value = this.currentValueFor[name];
 		return {
 			text: value[0] || "",
diff --git a/editions/tw5.com/tiddlers/releasenotes/5.4.0/#9494.tid b/editions/tw5.com/tiddlers/releasenotes/5.4.0/#9494.tid
new file mode 100644
index 0000000000..1729257323
--- /dev/null
+++ b/editions/tw5.com/tiddlers/releasenotes/5.4.0/#9494.tid
@@ -0,0 +1,10 @@
+title: $:/changenotes/5.4.0/#9494
+description: Fix LetWidget to always set all staged variables on first render
+release: 5.4.0
+tags: $:/tags/ChangeNote
+change-type: bugfix
+change-category: widget
+github-links: https://github.com/TiddlyWiki/TiddlyWiki5/pull/9494
+github-contributors: yaisog
+
+This PR corrects a bug where the LetWidget did not set variables if their value was the empty output of a filtered transclusion.