LaTeX writer: avoid \_ in bibliography variable.

Since underscores are common in filenames, and pandoc will
render strings to variables using default LaTeX escaping, we
special-case `bibliography`, under the assumption that this variable
will be used in the context of the `\bibliography{..}` command,
which accepts unescaped underscores.

Closes #11152.

src/Text/Pandoc/Writers/LaTeX.hs

@@ -215,7 +215,15 @@ pandocToLaTeX options (Pandoc meta blocks) = do
                            _         -> [])
                     $ lookupMetaInlines "nocite" meta
 
-  let context  =  defField "toc" (writerTableOfContents options) $
+   -- see #7414, avoid escaped underscores
+  let unescapeUnderscore = T.replace "\\_" "_"
+  let bibliography' = map unescapeUnderscore <$>
+                        getField "bibliography" metadata
+
+  let context  =  (case bibliography' of
+                     Nothing -> id
+                     Just xs -> resetField "bibliography" xs) $
+                  defField "toc" (writerTableOfContents options) $
                   defField "lof" (writerListOfFigures options) $
                   defField "lot" (writerListOfTables options) $
                   defField "toc-depth" (tshow

test/djot-reader.native

@@ -98,7 +98,7 @@ Pandoc
           [ Para [ Str "Code in a block quote:" ]
           , CodeBlock
               ( "" , [ "" ] , [] )
-              "sub status {\nprint \"working\";\n}\n"
+              "sub status {\n    print \"working\";\n}\n"
           , Para [ Str "A list:" ]
           , OrderedList
               ( 1 , Decimal , Period )