Allow --reference-doc to take URL argument.

Closes jgm#8535.

MANUAL.txt

@@ -1129,7 +1129,7 @@ header when requesting a document from a URL:
     user data directory (see `--data-dir`).  If it is not
     found there, sensible defaults will be used.
 
-`--reference-doc=`*FILE*
+`--reference-doc=`*FILE*|*URL*
 
 :   Use the specified file as a style reference in producing a
     docx or ODT file.

src/Text/Pandoc/Writers/Docx.hs

@@ -134,7 +134,8 @@ writeDocx opts doc = do
   P.setUserDataDir oldUserDataDir
   let distArchive = toArchive $ BL.fromStrict res
   refArchive <- case writerReferenceDoc opts of
-                     Just f  -> toArchive <$> P.readFileLazy f
+                     Just f  -> toArchive . BL.fromStrict . fst
+                                   <$> P.fetchItem (T.pack f)
                      Nothing -> toArchive . BL.fromStrict <$>
                           readDataFile "reference.docx"
 

src/Text/Pandoc/Writers/ODT.hs

@@ -94,7 +94,8 @@ pandocToODT opts doc@(Pandoc meta _) = do
   lang <- toLang (getLang opts meta)
   refArchive <-
        case writerReferenceDoc opts of
-             Just f -> liftM toArchive $ lift $ P.readFileLazy f
+             Just f -> lift $ toArchive . B.fromStrict . fst <$>
+                                (P.fetchItem (T.pack f))
              Nothing -> lift $ toArchive . B.fromStrict <$>
                                 readDataFile "reference.odt"
   -- handle formulas and pictures

src/Text/Pandoc/Writers/Powerpoint/Output.hs

@@ -578,7 +578,8 @@ presentationToArchive opts meta pres = do
   distArchive <- toArchive . BL.fromStrict <$>
                         readDefaultDataFile "reference.pptx"
   refArchive <- case writerReferenceDoc opts of
-                     Just f  -> toArchive <$> P.readFileLazy f
+                     Just f  -> toArchive . BL.fromStrict . fst
+                                  <$> P.fetchItem (T.pack f)
                      Nothing -> toArchive . BL.fromStrict <$>
                         readDataFile "reference.pptx"