LaTeX writer: ensure that beamer footnotes go on frame, not column.

Closes #5769.

cabal.project

@@ -5,7 +5,9 @@ packages: .
 tests: True
 flags: +embed_data_files
 constraints: skylighting-format-blaze-html >= 0.1.1.2,
-             skylighting-format-context >= 0.1.0.2
+             skylighting-format-context >= 0.1.0.2,
+             -- for now (commercialhaskell/stackage#7545):
+             data-default-class <= 0.2, data-default <= 0.8
 
 source-repository-package
   type: git

src/Text/Pandoc/Writers/LaTeX.hs

@@ -1128,8 +1128,9 @@ inlineToLaTeX (Note contents) = do
   let noteContents = nest 2 contents' <> optnl
   beamer <- gets stBeamer
   -- in beamer slides, display footnote from current overlay forward
+  -- and ensure that the note is on the frame, not e.g. the column (#5769)
   let beamerMark = if beamer
-                      then text "<.->"
+                      then text "<.->[frame]"
                       else empty
   if externalNotes
      then do