LaTeX reader: handle escaped & inside table cell.

Closes #3708.

src/Text/Pandoc/Readers/LaTeX.hs

@@ -1494,9 +1494,11 @@ parseTableRow :: PandocMonad m
               -> [String] -- ^ suffixes
               -> LP m [Blocks]
 parseTableRow cols prefixes suffixes = try $ do
-  let tableCellRaw = many (notFollowedBy
-                       (amp <|> lbreak <|>
-                         (() <$ try (string "\\end"))) >> anyChar)
+  let tableCellRaw = concat <$> many
+         (do notFollowedBy (amp <|> lbreak <|> (() <$ try (string "\\end")))
+             many1 (noneOf "&%\n\r\\")
+                  <|> try (string "\\&")
+                  <|> count 1 anyChar)
   let minipage = try $ controlSeq "begin" *> string "{minipage}" *>
           env "minipage"
           (skipopts *> spaces' *> optional braced *> spaces' *> blocks)

test/command/3708.md

@@ -0,0 +1,15 @@
+```
+% pandoc -f latex -t native
+\begin{tabular}{cc}
+    A & B\&1 \\
+    C & D
+\end{tabular}
+^D
+[Table [] [AlignCenter,AlignCenter] [0.0,0.0]
+ [[]
+ ,[]]
+ [[[Plain [Str "A"]]
+  ,[Plain [Str "B&1"]]]
+ ,[[Plain [Str "C"]]
+  ,[Plain [Str "D"]]]]]
+```