From 52b78b10c81e99926d560bc383938006be3b0458 Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Thu, 20 Jan 2022 19:09:44 -0800
Subject: [PATCH] Avoid putting a frame around speaker notes in beamer.

If speaker notes (a Div with class 'notes') occur right
after a section heading, but above slide level, the
resulting `\note{..}` caommand should not be wrapped in
a frame, as that will cause a spurious blank slide.

Closes #7857.
---
 src/Text/Pandoc/Writers/LaTeX.hs | 11 +++++++----
 test/command/7857.md             | 22 ++++++++++++++++++++++
 2 files changed, 29 insertions(+), 4 deletions(-)
 create mode 100644 test/command/7857.md

diff --git a/src/Text/Pandoc/Writers/LaTeX.hs b/src/Text/Pandoc/Writers/LaTeX.hs
index e16fcf13f..9f342f61f 100644
--- a/src/Text/Pandoc/Writers/LaTeX.hs
+++ b/src/Text/Pandoc/Writers/LaTeX.hs
@@ -235,10 +235,13 @@ elementToBeamer slideLevel (Div (ident,"section":dclasses,dkvs)
              isSlide _                         = False
          let (titleBs, slideBs) = break isSlide ys
          return $
-           if null titleBs
-              then Div (ident,"section":dclasses,dkvs) xs
-              else Div (ident,"section":dclasses,dkvs)
-                    (h : Div ("","slide":dclasses,dkvs) (h:titleBs) : slideBs)
+           case titleBs of
+              [] -> Div (ident,"section":dclasses,dkvs) xs
+              [Div (_,"notes":_,_) _] ->  -- see #7857, don't create frame
+                    -- just for speaker notes after section heading
+                    Div (ident,"section":dclasses,dkvs) xs
+              _  -> Div (ident,"section":dclasses,dkvs)
+                     (h : Div ("","slide":dclasses,dkvs) (h:titleBs) : slideBs)
   | otherwise
     = return $ Div (ident,"slide":dclasses,dkvs) xs
 elementToBeamer _ x = return x
diff --git a/test/command/7857.md b/test/command/7857.md
new file mode 100644
index 000000000..9a4968e88
--- /dev/null
+++ b/test/command/7857.md
@@ -0,0 +1,22 @@
+```
+% pandoc --slide-level=2 -t beamer
+# section
+
+::: notes
+my note
+:::
+
+## slide
+
+ok
+^D
+\hypertarget{section}{%
+\section{section}\label{section}}
+
+\note{my note}
+
+\begin{frame}{slide}
+\protect\hypertarget{slide}{}
+ok
+\end{frame}
+```