Made user directory a Maybe in readFile, s5HeaderIncludes, laTeXMathML.

This is more uniform, and calling libraries can always disable
searching of user directories for overrides.

git-svn-id: https://pandoc.googlecode.com/svn/trunk@1821 788f1e2b-df1e-0410-8736-df70ead52e1b

1 files changed, 6 insertions, 4 deletions

diff --git a/src/Text/Pandoc/Shared.hs b/src/Text/Pandoc/Shared.hs
index 5657321d8..14086c20f 100644
--- a/src/Text/Pandoc/Shared.hs
+++ b/src/Text/Pandoc/Shared.hs
@@ -1046,7 +1046,9 @@ inDirectory path action = do
 
 -- | Read file from specified user data directory or, if not found there, from
 -- Cabal data directory.
-readDataFile :: FilePath -> FilePath -> IO String
-readDataFile userDir fname = catch
-  (readFile $ userDir </> fname)
-  (\_ -> getDataFileName fname >>= readFile)
+readDataFile :: Maybe FilePath -> FilePath -> IO String
+readDataFile userDir fname =
+  case userDir of
+       Nothing  -> getDataFileName fname >>= readFile
+       Just u   -> catch (readFile $ u </> fname)
+                   (\_ -> getDataFileName fname >>= readFile)