tikz: reset \tikz@expandcount more frequent #969

[muzimuzhi]

This makes \tikz@expandcount get reset every time a token is handled
in tikz path scanning.

Motivation for this change

Fixes #969

Checklist

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• Code changes are licensed under GPLv2 + LPPLv1.3c
• Documentation changes are licensed under FDLv1.2

[hmenke]

1000 seemed really excessive. It was probably set to 1000 because it would never be reset.

[muzimuzhi]

appreciate the cleaning up

[hmenke]

@muzimuzhi What do you think about a9a0f97?

[muzimuzhi]

very well, even impressive (except for the lua emulated \pgfsys@strcmp because I know little about luatex)

[muzimuzhi]

@hmenke Are there any concerns that blocked this PR to be merged? Considering its current title, I think it has included well enough changes/improvements.

[hmenke]

Should we discuss again the “\relax on a path” issue? We could add another case distinction like

{\relax}{\relax\tikz@scan@next@command}%

Which would reinsert \relax and continue scanning. Does that solve the \ifnum\x=\y\relax thing?

[muzimuzhi]

Ah, I mistakenly though the \relax would be handled in another PR.

Yes I guess that would solve the \ifnum... thing, and will test it soon. Noticed \par is already handled as {\par}{\tikz@scan@next@command}, using {\relax}{\relax\tikz@scan@next@command} looks convincing.

[hmenke]

TeX Live failed to update. Let's see if rerunning helps.