\input regression-test.tex
\DocumentMetadata{}
\documentclass{ltx-talk}
\NewDocumentCommand\lecture{O{}mm}{\TYPE{LECTURE KEPT}}
\usepackage[ignorenonframetext]{osglecture-modes-ltxtalk}

\NewDocumentCommand\ollabel{m}{\TYPE{OLLABEL~#1}}
\DeclareLectureKeepLabelCommand\ollabel

\NewDocumentCommand\mycmd{m}{\TYPE{MYCMD~#1}}
\DeclareLectureKeepCommand\mycmd

\NewDocumentEnvironment{myenv}{}{\TYPE{MYENV~BEGIN}}{\TYPE{MYENV~END}}
\DeclareLectureKeepEnvironment{myenv}

\begin{document}
% Force any lazily-loaded fallback font (e.g. a math package's TU+lmr-base)
% to load here, before \START opens the recorded transcript: NFSS only
% emits its one-time "Trying to load font information" notice on first
% use, and which page first needs a given fallback family is an
% installation detail, not something this test cares about.
\IfFileExists{tulmr-base.fd}{\usefont{TU}{lmr-base}{m}{n}}{}
\START
\lecture{Introduction}{intro}
\section{Sec}
\ollabel{kept}
\foobar
\ollabel{dropped}
\mycmd{always}
\begin{myenv}
  \TYPE{MYENV CONTENT}
\end{myenv}
\mycmd{after-env}
\begin{unregisteredenv}
  \TYPE{SHOULD NOT APPEAR}
\end{unregisteredenv}
\begin{frame}
  \TYPE{FRAME KEPT}
\end{frame}
\END
\end{document}