LaTeX reader: don't apply theorem default styling to a figure inside.

If we put an image in italics, then when rendering to Markdown
we no longer get an implicit figure.

Closes #6925.

src/Text/Pandoc/Readers/LaTeX.hs

@@ -1812,6 +1812,7 @@ theoremEnvironment name = do
                   _          -> bs
 
 italicize :: Block -> Block
+italicize x@(Para [Image{}]) = x -- see #6925
 italicize (Para ils) = Para [Emph ils]
 italicize (Plain ils) = Plain [Emph ils]
 italicize x = x

test/command/6925.md

@@ -0,0 +1,34 @@
+```
+% pandoc -f latex -t markdown
+\documentclass{amsart}
+\newtheorem{thm}{Theorem}[section]
+\theoremstyle{definition}
+\newtheorem{thm2}[section]{Theorem}
+\begin{document}
+\begin{thm}
+a
+\begin{figure}
+\includegraphics[]{1.png}
+\end{figure}
+\end{thm}
+
+\begin{thm2}
+a
+\begin{figure}
+\includegraphics[]{1.png}
+\end{figure}
+\end{thm2}
+\end{document}
+^D
+::: {.thm}
+**Theorem 1**. *a*
+
+![image](1.png)
+:::
+
+::: {.thm2}
+**Theorem 1**. a
+
+![image](1.png)
+:::
+```