Fix infinite loop in example under Section 2.6.2 Loops over list of items

Author: hansonchar

doc/latex/pgfplots/ChangeLog

@@ -1,3 +1,7 @@
+2024-07-10 Hanson Char <hanson.char@gmail.com>
+
+	Fix infinite loop in example under Section 2.6.2 Loops over list of items
+
 2021-12-27 Christian Feuersaenger <cfeuersaenger@users.sourceforge.net>
 
 	fix linux file read permissions of some new lua files in TDS zip

doc/latex/pgfplots/TeX-programming-notes.tex

@@ -926,7 +926,7 @@ \subsubsection{Loops over list of items}
 }%
 \long\def\looppicker#1#2#3,{%
 	\def\tempitem{#3}%
-	\ifx\tempitem\listingloopENDMARKER
+	\expandafter\ifx\tempitem\listingloopENDMARKER
 		\let\next=\relax%
 	\else
 		\def#1{#3}%