\pgfmatrix: slightly simplify adding row separation.

Make less dimension calculations, glue insertions, assignments
for the same result.

Author: gabor-braun

tex/generic/pgf/modules/pgfmodulematrix.code.tex

@@ -609,24 +609,24 @@
 }%
 
 \def\pgf@matrix@finish@line{%
-  \pgf@ya=-\pgf@y%
-  \global\advance\pgf@ya by\csname pgf@matrix@miny\the\pgfmatrixcurrentrow\endcsname%
-  \expandafter\xdef\csname pgf@matrix@miny\the\pgfmatrixcurrentrow\endcsname{\the\pgf@ya}%
   \pgfutil@ifnextchar\egroup%
   {\egroup\pgf@end@matrix}{\pgf@matrix@no@eom@found\egroup}%
 }%
 
 \def\pgf@matrix@no@eom@found{%
   \vskip\pgf@y%
+  \pgf@y=-\pgf@y%
   \ifpgf@matrix@fixed%
     \vskip\csname pgf@matrix@miny\the\pgfmatrixcurrentrow\endcsname% unskip
-    \vskip\pgf@y%
-    \pgf@y=-\pgf@y%
-    \expandafter\xdef\csname pgf@matrix@miny\the\pgfmatrixcurrentrow\endcsname{\the\pgf@y}%
     \gdef\pgf@matrix@row@finish{\global\pgf@picmaxy=0pt}%
   \else%
+    \advance\pgf@y by%
+      \csname pgf@matrix@miny\the\pgfmatrixcurrentrow\endcsname%
     \global\let\pgf@matrix@row@finish=\pgfutil@empty%
   \fi%
+  \expandafter\xdef%
+    \csname pgf@matrix@miny\the\pgfmatrixcurrentrow\endcsname%
+    {\the\pgf@y}%
   \pgf@matrix@init@row%
 }%