Use latest citeproc.

cabal.project

@@ -7,5 +7,5 @@ package pandoc
 source-repository-package
     type: git
     location: https://github.com/jgm/citeproc
-    tag: dc7ad5a8780d3bb12c437edf15f966f03c4be43f
+    tag: 5e76be59977e8998b9c2232da8e71ec6360ff26b
 constraints: base16-bytestring < 1

pandoc.cabal

@@ -403,7 +403,7 @@ library
                  blaze-markup          >= 0.8      && < 0.9,
                  bytestring            >= 0.9      && < 0.12,
                  case-insensitive      >= 1.2      && < 1.3,
-                 citeproc              >= 0.0      && < 0.1,
+                 citeproc              >= 0.1      && < 0.2,
                  commonmark            >= 0.1.0.2  && < 0.2,
                  commonmark-extensions >= 0.2      && < 0.3,
                  commonmark-pandoc     >= 0.2      && < 0.3,

src/Text/Pandoc/Citeproc/BibTeX.hs

@@ -30,8 +30,7 @@ import Text.Pandoc.Error (PandocError)
 import Text.Pandoc.Shared (stringify)
 import qualified Text.Pandoc.Walk       as Walk
 import Citeproc.Types
-import Citeproc.CaseTransform (withSentenceCase)
-import Citeproc.Pandoc (caseTransform)
+import Citeproc.Pandoc
 import Text.Pandoc.Citeproc.Util (toIETF)
 import Text.Pandoc.Citeproc.Data (biblatexStringMap)
 import Data.Default
@@ -736,7 +735,7 @@ protectCase f = Walk.walk unprotect . f . Walk.walk protect
   startsWithLowercase _           = False
 
 unTitlecase :: Maybe Lang -> Inlines -> Inlines
-unTitlecase mblang = protectCase (caseTransform (withSentenceCase mblang))
+unTitlecase mblang = protectCase (addTextCase mblang SentenceCase)
 
 getTitle :: Text -> Bib Inlines
 getTitle f = do

stack.yaml

@@ -7,7 +7,7 @@ packages:
 - '.'
 extra-deps:
 - git: https://github.com/jgm/citeproc
-  commit: dc7ad5a8780d3bb12c437edf15f966f03c4be43f
+  commit: 5e76be59977e8998b9c2232da8e71ec6360ff26b
 - pandoc-types-1.22
 - texmath-0.12.0.3
 - rfc5051-0.2