From 938e72dc3460f593833ccaa2bf2a4d02b63173dd Mon Sep 17 00:00:00 2001
From: Jeremy Ruston <jeremy@jermolene.com>
Date: Wed, 19 Mar 2025 11:00:03 +0000
Subject: [PATCH] Bug fix

---
 core/modules/filterrunprefixes/let.js                |  8 +++++---
 .../let-filter-prefix/ResultListUnnamedVariable.tid  | 12 ++++++++++++
 .../data/multi-valued-variables/MissingVariable.tid  | 12 ++++++++++++
 3 files changed, 29 insertions(+), 3 deletions(-)
 create mode 100644 editions/test/tiddlers/tests/data/let-filter-prefix/ResultListUnnamedVariable.tid
 create mode 100644 editions/test/tiddlers/tests/data/multi-valued-variables/MissingVariable.tid

diff --git a/core/modules/filterrunprefixes/let.js b/core/modules/filterrunprefixes/let.js
index d8afdd1a1..3fa3569f5 100644
--- a/core/modules/filterrunprefixes/let.js
+++ b/core/modules/filterrunprefixes/let.js
@@ -18,6 +18,10 @@ Export our filter prefix function
 exports.let = function(operationSubFunction,options) {
 	// Return the filter run prefix function
 	return function(results,source,widget) {
+		// Save the result list
+		var resultList = results.toArray();
+		// Clear the results
+		results.clear();
 		// Evaluate the subfunction to get the variable name
 		var subFunctionResults = operationSubFunction(source,widget);
 		if(subFunctionResults.length === 0) {
@@ -29,9 +33,7 @@ exports.let = function(operationSubFunction,options) {
 		}
 		// Assign the result of the subfunction to the variable
 		var variables = {};
-		variables[name] = results.toArray()
-		// Clear the results
-		results.clear();
+		variables[name] = resultList;
 		// Return the variables
 		return {
 			variables: variables
diff --git a/editions/test/tiddlers/tests/data/let-filter-prefix/ResultListUnnamedVariable.tid b/editions/test/tiddlers/tests/data/let-filter-prefix/ResultListUnnamedVariable.tid
new file mode 100644
index 000000000..7f8c8525b
--- /dev/null
+++ b/editions/test/tiddlers/tests/data/let-filter-prefix/ResultListUnnamedVariable.tid
@@ -0,0 +1,12 @@
+title: LetFilterRunPrefix/ResultListUnnamedVariable
+description: Using the "let" filter run prefix to store result lists, not just single values
+type: text/vnd.tiddlywiki-multiple
+tags: [[$:/tags/wiki-test-spec]]
+
+title: Output
+
+<$text text={{{ [all[tiddlers]] :let[all[]tag[nothing]] [varlist[varname]sort[]join[,]] }}}/>
++
+title: ExpectedResult
+
+<p></p>
\ No newline at end of file
diff --git a/editions/test/tiddlers/tests/data/multi-valued-variables/MissingVariable.tid b/editions/test/tiddlers/tests/data/multi-valued-variables/MissingVariable.tid
new file mode 100644
index 000000000..30744d844
--- /dev/null
+++ b/editions/test/tiddlers/tests/data/multi-valued-variables/MissingVariable.tid
@@ -0,0 +1,12 @@
+title: MultiValuedVariables/MissingVariable
+description: Using varlist with a missing variable
+type: text/vnd.tiddlywiki-multiple
+tags: [[$:/tags/wiki-test-spec]]
+
+title: Output
+
+<$text text={{{ [varlist[varname]] }}}/>
++
+title: ExpectedResult
+
+<p></p>
\ No newline at end of file