fix: expand functions before space trimming

Signed-off-by: Yukai Chou <[email protected]>

Author: muzimuzhi

tex/generic/pgf/frontendlayer/tikz/tikz.code.tex

@@ -3366,7 +3366,7 @@
   \def\tikz@plot@filename{\tikz@plot@prefix\tikz@plot@id}%
   \iftikz@plot@raw@gnuplot%
     \def\tikz@plot@data{%
-      \pgfplotgnuplot[\tikz@plot@filename]{\pgfutil@trimspaces{#1}}}%
+      \pgfplotgnuplot[\tikz@plot@filename]{\pgfutil@trimspaces@e{#1}}}%
   \else%
     \iftikz@plot@parametric%
       \def\tikz@plot@data{\pgfplotgnuplot[\tikz@plot@filename]{%
@@ -3375,13 +3375,13 @@
           plot [t=\tikz@plot@domain]
           [\tikz@plot@xrange]
           [\tikz@plot@range]
-          \pgfutil@trimspaces{#1}}}%
+          \pgfutil@trimspaces@e{#1}}}%
     \else%
       \def\tikz@plot@data{\pgfplotgnuplot[\tikz@plot@filename]{%
           set samples \tikz@plot@samples;
           plot [x=\tikz@plot@domain]
           \ifx\tikz@plot@range\pgfutil@empty\else[\tikz@plot@range]\fi
-          \pgfutil@trimspaces{#1}}}%
+          \pgfutil@trimspaces@e{#1}}}%
     \fi%
   \fi%
   \tikz@@@plot%

tex/generic/pgf/modules/pgfmoduleplot.code.tex

@@ -490,7 +490,7 @@
     \pgfutil@read\pgfutil@inputcheck to\pgf@temp% ignored
     \pgfutil@read\pgfutil@inputcheck to\pgf@plot@line%
     \closein\pgfutil@inputcheck
-    \edef\pgf@plot@code{#2}%
+    \edef\pgf@plot@code{\pgfutil@trimspaces@e{#2}}% in case of leading spaces
     \ifx\pgf@plot@code\pgf@plot@line%
       \openin\pgfutil@inputcheck=\pgfretval\relax
       \ifeof\pgfutil@inputcheck%

tex/generic/pgf/utilities/pgfutil-common.tex

@@ -49,6 +49,10 @@
 \def\pgfutil@trimspaces@@#1Q#2{#1}
 \catcode`\Q=11
 
+\def\pgfutil@trimspaces@e#1{%
+  \expandafter\pgfutil@trimspaces\expandafter{\pgfutil@expanded{#1}}%
+}
+
 % \pgfutil@ifx{<token 1>}{<token 2>}{<true code>}{<false code>}
 %
 % This macro is expandable.