Revert "EPUB writer: stylesheet changes. Closes #2040."

This reverts commit 1c2951dfd9.

See #2040.

The semantics was too squishy.  `--css` takes a URL, but
for EPUB we need files that we can read.  I prefer keeping
the old system for now, with `--epub-stylesheet`.

README

@@ -646,8 +646,6 @@ Options affecting specific writers
     is specified, pandoc will look for a file `epub.css` in the
     user data directory (see `--data-dir`).  If it is not
     found there, sensible defaults will be used.
-    (*Deprecated:* use `--css` or the `stylesheet` metadata field
-    instead.)
 
 `--epub-cover-image=`*FILE*
 

pandoc.hs

@@ -689,10 +689,8 @@ options =
     , Option "" ["epub-stylesheet"]
                  (ReqArg
                   (\arg opt -> do
-                     warn "--epub-stylesheet is deprecated. Use --css or stylesheet in metadata."
-                     let newvars = optVariables opt ++ [("css",arg)]
-                     return opt { optVariables = newvars,
-                                  optStandalone = True })
+                     text <- UTF8.readFile arg
+                     return opt { optEpubStylesheet = Just text })
                   "FILENAME")
                  "" -- "Path of epub.css"
 

src/Text/Pandoc/Writers/EPUB.hs

@@ -99,7 +99,7 @@ data EPUBMetadata = EPUBMetadata{
   , epubPageDirection      :: Maybe ProgressionDirection
   } deriving Show
 
-data Stylesheet = StylesheetPaths [FilePath]
+data Stylesheet = StylesheetPath FilePath
                 | StylesheetContents String
                 deriving Show
 
@@ -323,14 +323,8 @@ metadataFromMeta opts meta = EPUBMetadata{
         coverImage = lookup "epub-cover-image" (writerVariables opts) `mplus`
              (metaValueToString <$> lookupMeta "cover-image" meta)
         stylesheet = (StylesheetContents <$> writerEpubStylesheet opts) `mplus`
-                     (case lookupMeta "stylesheet" meta of
-                         Just (MetaBlocks [CodeBlock (_,["css"],_) code])
-                                -> Just (StylesheetContents code)
-                         Just x -> Just (StylesheetPaths [metaValueToString x])
-                         Nothing -> Nothing) `mplus`
-                     (case [x | ("css", x) <- writerVariables opts] of
-                           []   -> Nothing
-                           xs   -> Just (StylesheetPaths xs))
+                     ((StylesheetPath . metaValueToString) <$>
+                       lookupMeta "stylesheet" meta)
         pageDirection = case map toLower . metaValueToString <$>
                              lookupMeta "page-progression-direction" meta of
                               Just "ltr" -> Just LTR
@@ -346,21 +340,20 @@ writeEPUB opts doc@(Pandoc meta _) = do
   let epub3 = version == EPUB3
   epochtime <- floor `fmap` getPOSIXTime
   let mkEntry path content = toEntry path epochtime content
-  let vars = ("epub3", if epub3 then "true" else "false") :
-             writerVariables opts
-  let opts'' = opts{ writerEmailObfuscation = NoObfuscation
-                   , writerStandalone = True
-                   , writerSectionDivs = True
-                   , writerHtml5 = epub3
-                   , writerVariables = vars
-                   , writerHTMLMathMethod =
-                        if epub3
-                           then MathML Nothing
-                           else writerHTMLMathMethod opts
-                   , writerWrapText = True }
-  metadata <- getEPUBMetadata opts'' meta
-  let opts' = opts''{ writerVariables = ("css", "stylesheet.css") :
-                      filter (\(x,_) -> x /= "css") vars }
+  let vars = ("epub3", if epub3 then "true" else "false")
+           : ("css", "stylesheet.css")
+           : writerVariables opts
+  let opts' = opts{ writerEmailObfuscation = NoObfuscation
+                  , writerStandalone = True
+                  , writerSectionDivs = True
+                  , writerHtml5 = epub3
+                  , writerVariables = vars
+                  , writerHTMLMathMethod =
+                       if epub3
+                          then MathML Nothing
+                          else writerHTMLMathMethod opts
+                  , writerWrapText = True }
+  metadata <- getEPUBMetadata opts' meta
 
   -- cover page
   (cpgEntry, cpicEntry) <-
@@ -682,8 +675,7 @@ writeEPUB opts doc@(Pandoc meta _) = do
 
   -- stylesheet
   stylesheet <- case epubStylesheet metadata of
-                   Just (StylesheetPaths fp)   -> concat <$>
-                                                  mapM UTF8.readFile fp
+                   Just (StylesheetPath fp)    -> UTF8.readFile fp
                    Just (StylesheetContents s) -> return s
                    Nothing -> UTF8.toString `fmap`
                               readDataFile (writerUserDataDir opts) "epub.css"