BibTeX writer fixes. Closes #7067.

+ Require citeproc 0.3.0.7, which correctly titlecases when titles
  contain non-ASCII characters.
+ Correctly handle 'pages' (= 'page' in CSL).
+ Correctly handle BibLaTeX 'langid' (= 'language' in CSL).
+ In BibTeX output, protect foreign titles since there's no language
  field.

pandoc.cabal

@@ -410,7 +410,7 @@ library
                  blaze-markup          >= 0.8      && < 0.9,
                  bytestring            >= 0.9      && < 0.12,
                  case-insensitive      >= 1.2      && < 1.3,
-                 citeproc              >= 0.3.0.6  && < 0.4,
+                 citeproc              >= 0.3.0.7  && < 0.4,
                  commonmark            >= 0.1.1.3  && < 0.2,
                  commonmark-extensions >= 0.2.0.4  && < 0.3,
                  commonmark-pandoc     >= 0.2      && < 0.3,

src/Text/Pandoc/Citeproc/BibTeX.hs

@@ -149,7 +149,7 @@ writeBibtexString opts variant mblang ref =
            , "type"
            , "entrysubtype"
            , "note"
-           , "language"
+           , "langid"
            , "abstract"
            , "keywords"
            ]
@@ -202,12 +202,19 @@ writeBibtexString opts variant mblang ref =
                    [ (", " <>) <$> nameGiven name,
                      nameDroppingParticle name ]
 
-  titlecase = case mblang of
+  mblang' = (parseLang <$> getVariableAsText "language") <|> mblang
+
+  titlecase = case mblang' of
                 Just (Lang "en" _) -> titlecase'
                 Nothing            -> titlecase'
-                _                  -> id
+                _                  ->
+                  case variant of
+                    Bibtex         -> B.spanWith nullAttr
+                     -- BibTex lacks a language field, so we wrap non-English
+                     -- titles in {} to protect case.
+                    Biblatex       -> id
 
-  titlecase' = addTextCase mblang TitleCase .
+  titlecase' = addTextCase mblang' TitleCase .
     (\ils -> B.fromList
                (case B.toList ils of
                   Str t : xs -> Str t : Walk.walk spanAroundCapitalizedWords xs
@@ -299,6 +306,8 @@ writeBibtexString opts variant mblang ref =
   getContentsFor "urldate"  = getVariable "accessed" >>= toLaTeX . valToInlines
   getContentsFor "year"  = getVariable "issued" >>= getYear
   getContentsFor "month"  = getVariable "issued" >>= getMonth
+  getContentsFor "pages"  = getVariable "page" >>= toLaTeX . valToInlines
+  getContentsFor "langid"  = getVariable "language" >>= toLaTeX . valToInlines
   getContentsFor "number" = (getVariable "number"
                          <|> getVariable "collection-number"
                          <|> getVariable "issue") >>= toLaTeX . valToInlines

stack.yaml

@@ -19,10 +19,10 @@ extra-deps:
 - doctemplates-0.9
 - texmath-0.12.1
 - tasty-bench-0.1
-- citeproc-0.3.0.6
+- citeproc-0.3.0.7
 #- citeproc:
 #  git: https://github.com/jgm/citeproc.git
-#  commit: da1f9702fa70d7e1bad9a796f897e920e2d578f7
+#  commit: feb3b7580c6738eec3b23921f7c1739cfba611aa
 ghc-options:
    "$locals": -fhide-source-paths -Wno-missing-home-modules
 resolver: lts-16.23

test/command/7067.md

@@ -0,0 +1,90 @@
+```
+% pandoc -t biblatex
+---
+references:
+- id: garaud
+  author:
+    - family: Garaud
+      given: Marcel
+  container-title: Bulletin de la Societé des antiquaires de l’Ouest
+  collection-title: 4
+  issued:
+    - year: 1967
+  language: fr-FR
+  page: 11-27
+  title: Recherches sur les défrichements dans la Gâtine poitevine aux XI^e^ et XII^e^ siècles
+  type: article-journal
+  volume: 9
+...
+^D
+@article{garaud,
+  author = {Garaud, Marcel},
+  title = {Recherches sur les défrichements dans la Gâtine poitevine aux
+XI\textsuperscript{e} et XII\textsuperscript{e} siècles},
+  journal = {Bulletin de la Societé des antiquaires de l’Ouest},
+  series = {4},
+  volume = {9},
+  pages = {11-27},
+  date = {1967},
+  langid = {fr-FR}
+}
+```
+
+```
+% pandoc -t bibtex
+---
+references:
+- id: garaud
+  author:
+    - family: Garaud
+      given: Marcel
+  container-title: Bulletin de la Société des antiquaires de l’Ouest
+  collection-title: 4
+  issued:
+    - year: 1967
+  language: fr-FR
+  page: 11-27
+  title: Recherches sur les défrichements dans la Gâtine poitevine aux XI^e^ et XII^e^ siècles
+  type: article-journal
+  volume: 9
+...
+^D
+@article{garaud,
+  author = {Garaud, Marcel},
+  title = {{Recherches sur les défrichements dans la Gâtine poitevine aux
+XI\textsuperscript{e} et XII\textsuperscript{e} siècles}},
+  journal = {Bulletin de la Société des antiquaires de l’Ouest},
+  series = {4},
+  volume = {9},
+  pages = {11-27},
+  year = {1967}
+}
+```
+
+This tests the titlecasing of a word with an accented second letter:
+```
+% pandoc -t bibtex
+---
+references:
+- id: garaud
+  author:
+    - family: Garaud
+      given: Marcel
+  container-title: English Journal
+  issued:
+    - year: 1967
+  language: en-US
+  title: Research on the défrichements in the Gâtine poitevine
+  type: article-journal
+  volume: 9
+...
+^D
+@article{garaud,
+  author = {Garaud, Marcel},
+  title = {Research on the Défrichements in the {Gâtine} Poitevine},
+  journal = {English Journal},
+  volume = {9},
+  year = {1967}
+}
+```
+