Incorrect parsing of material for protrusion

[FrankMittelbach]

Description

output fontsizes are wrong if a font size change is encountered while parsing

pdftex but probably in the others too

Minimal example demonstrating the issue

\documentclass{article}
\usepackage%[nopatch]
 {microtype}

\begin{document}

x
\begin{quote}
  \tiny
  {abc} \\   % braces for color for example
  wrong size
\end{quote}
\end{document}

problem is that

• \tiny is collected,
• { is immediately executed
• then ab is collected

so that you end up executing

  \bgroup \tiny ab ... }

in the end and \normalsize restored at the }and not at the \end{quote}

[schlcht]

I guess this is the same problem as in #52 .