EPUB writer: ensure that pagetitle is always set...

even when structured titles are used.
This prevents spurious warnings about empty title elements.

Closes #4486.

1 files changed, 12 insertions, 6 deletions

diff --git a/src/Text/Pandoc/Writers/EPUB.hs b/src/Text/Pandoc/Writers/EPUB.hs
index 8d0a46949..f1ff8b482 100644
--- a/src/Text/Pandoc/Writers/EPUB.hs
+++ b/src/Text/Pandoc/Writers/EPUB.hs
@@ -403,6 +403,12 @@ pandocToEPUB version opts doc@(Pandoc meta _) = do
                       writeHtmlStringForEPUB version o
   metadata <- getEPUBMetadata opts meta
 
+  let plainTitle = case docTitle' meta of
+                        [] -> case epubTitle metadata of
+                                   []    -> "UNTITLED"
+                                   (x:_) -> titleText x
+                        x  -> stringify x
+
   -- stylesheet
   stylesheets <- case epubStylesheets metadata of
                       [] -> (\x -> [B.fromChunks [x]]) <$>
@@ -440,6 +446,7 @@ pandocToEPUB version opts doc@(Pandoc meta _) = do
                        cpContent <- lift $ writeHtml
                             opts'{ writerVariables =
                                     ("coverpage","true"):
+                                    ("pagetitle",plainTitle):
                                      cssvars True ++ vars }
                             (Pandoc meta [RawBlock (Format "html") $ "<div id=\"cover-image\">\n<img src=\"../media/" ++ coverImage ++ "\" alt=\"cover image\" />\n</div>"])
                        imgContent <- lift $ P.readFileLazy img
@@ -452,6 +459,7 @@ pandocToEPUB version opts doc@(Pandoc meta _) = do
   -- title page
   tpContent <- lift $ writeHtml opts'{
                                   writerVariables = ("titlepage","true"):
+                                  ("pagetitle",plainTitle):
                                   cssvars True ++ vars }
                                (Pandoc meta [])
   tpEntry <- mkEntry "text/title_page.xhtml" tpContent
@@ -604,11 +612,6 @@ pandocToEPUB version opts doc@(Pandoc meta _) = do
                                      $ eRelativePath ent),
                             ("media-type", fromMaybe "" $
                                   getMimeType $ eRelativePath ent)] $ ()
-  let plainTitle = case docTitle' meta of
-                        [] -> case epubTitle metadata of
-                                   []    -> "UNTITLED"
-                                   (x:_) -> titleText x
-                        x  -> stringify x
 
   let tocTitle = fromMaybe plainTitle $
                    metaValueToString <$> lookupMeta "toc-title" meta
@@ -749,7 +752,10 @@ pandocToEPUB version opts doc@(Pandoc meta _) = do
           where titElements = parseXML titRendered
                 titRendered = case P.runPure
                                (writeHtmlStringForEPUB version
-                                 opts{ writerTemplate = Nothing }
+                                 opts{ writerTemplate = Nothing
+                                     , writerVariables =
+                                       ("pagetitle",plainTitle):
+                                       writerVariables opts}
                                  (Pandoc nullMeta
                                    [Plain $ walk clean tit])) of
                                 Left _  -> TS.pack $ stringify tit