From 7fac39528497b35915a5573c1ac3faf875476272 Mon Sep 17 00:00:00 2001
From: John MacFarlane <jgm@berkeley.edu>
Date: Sat, 2 Nov 2019 11:04:21 -0700
Subject: [PATCH] LaTeX reader: Don't omit macro definitions defined in the
 preamble.

These were formerly omitted (though they still affected macro
resolution if `latex_macros` was set).  Now they are included in
the document.
---
 src/Text/Pandoc/Readers/LaTeX.hs | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/src/Text/Pandoc/Readers/LaTeX.hs b/src/Text/Pandoc/Readers/LaTeX.hs
index a8df5dd03..b4e9de258 100644
--- a/src/Text/Pandoc/Readers/LaTeX.hs
+++ b/src/Text/Pandoc/Readers/LaTeX.hs
@@ -1462,13 +1462,14 @@ end_ t = try (do
   guard $ t == txt) <?> ("\\end{" ++ T.unpack t ++ "}")
 
 preamble :: PandocMonad m => LP m Blocks
-preamble = mempty <$ many preambleBlock
-  where preambleBlock =  spaces1
-                     <|> macroDef (const ())
-                     <|> void blockCommand
-                     <|> void braced
+preamble = mconcat <$> many preambleBlock
+  where preambleBlock =  (mempty <$ spaces1)
+                     <|> macroDef (rawBlock "latex")
+                     <|> (mempty <$ blockCommand)
+                     <|> (mempty <$ braced)
                      <|> (do notFollowedBy (begin_ "document")
-                             void anyTok)
+                             anyTok
+                             return mempty)
 
 paragraph :: PandocMonad m => LP m Blocks
 paragraph = do