\DocumentMetadata{}
\input regression-test.tex
\documentclass{ltx-talk}
\usepackage{ltxtalk-theme}

\begin{document}
\START
\ExplSyntaxOn

\dim_set:Nn \l_tmpa_dim {\textheight}

\ltxtalksetup
  {header=true,header-height=14mm,footer=true,footer-height=12mm}

\dim_compare:nNnTF {\use:c{Gm@tmargin}} = {14mm+\headsep}
  {\TYPE{header-margin:passed}}
  {\TYPE{header-margin:FAILED}}
\dim_compare:nNnTF {\use:c{Gm@bmargin}} = {12mm}
  {\TYPE{footer-margin:passed}}
  {\TYPE{footer-margin:FAILED}}
\dim_compare:nNnTF {\textheight} = {\paperheight-14mm-\headsep-12mm}
  {\TYPE{textheight:passed}}
  {\TYPE{textheight:FAILED}}
\dim_compare:nNnTF {\topmargin} = {14mm-1in-\headheight}
  {\TYPE{topmargin:passed}}
  {\TYPE{topmargin:FAILED}}
\dim_compare:nNnTF {\use:c{@colht}} = {\textheight}
  {\TYPE{colht:passed}}
  {\TYPE{colht:FAILED}}

% Title layouts carry their own spacing and retain the class text geometry.
\bool_set_true:N \l__ltxtalk_title_page_bool
\ltxtalksetup
  {header=true,header-height=24mm,footer=true,footer-height=12mm}
\dim_compare:nNnTF {\use:c{Gm@tmargin}} = {\LTXTalkBaseTopMargin}
  {\TYPE{title-top:passed}}
  {\TYPE{title-top:FAILED}}
\dim_compare:nNnTF {\use:c{Gm@bmargin}} = {\LTXTalkBaseBottomMargin}
  {\TYPE{title-bottom:passed}}
  {\TYPE{title-bottom:FAILED}}
\bool_set_false:N \l__ltxtalk_title_page_bool

% Shallow theme areas must not reduce the class's original whitespace.
\ltxtalksetup
  {header=true,header-height=1mm,footer=true,footer-height=1mm}
\dim_compare:nNnTF {\use:c{Gm@tmargin}} = {\LTXTalkBaseTopMargin}
  {\TYPE{shallow-header:passed}}
  {\TYPE{shallow-header:FAILED}}
\dim_compare:nNnTF {\use:c{Gm@bmargin}} = {\LTXTalkBaseBottomMargin}
  {\TYPE{shallow-footer:passed}}
  {\TYPE{shallow-footer:FAILED}}

% Disabling both areas restores the complete original vertical geometry.
\ltxtalksetup{header=false,footer=false}
\dim_compare:nNnTF {\use:c{Gm@tmargin}} = {\LTXTalkBaseTopMargin}
  {\TYPE{restore-top:passed}}
  {\TYPE{restore-top:FAILED}}
\dim_compare:nNnTF {\use:c{Gm@bmargin}} = {\LTXTalkBaseBottomMargin}
  {\TYPE{restore-bottom:passed}}
  {\TYPE{restore-bottom:FAILED}}
\dim_compare:nNnTF {\textheight} = {\l_tmpa_dim}
  {\TYPE{restore-height:passed}}
  {\TYPE{restore-height:FAILED}}

\ExplSyntaxOff
\END
\end{document}