Docx Writer: handle image alt text, closes jgm#2754

src/Text/Pandoc/Writers/Docx.hs

@@ -40,11 +40,13 @@ import Codec.Archive.Zip
 import Data.Time.Clock.POSIX
 import Data.Time.Clock
 import System.Environment
+import qualified Text.Pandoc.Builder as B
 import Text.Pandoc.Compat.Time
 import Text.Pandoc.Definition
 import Text.Pandoc.Generic
 import Text.Pandoc.ImageSize
 import Text.Pandoc.Shared hiding (Element)
+import Text.Pandoc.Writers.Markdown (writePlain)
 import Text.Pandoc.Writers.Shared (fixDisplayMath)
 import Text.Pandoc.Options
 import Text.Pandoc.Readers.TeXMath
@@ -1103,7 +1105,7 @@ inlineToOpenXML opts (Link _ txt (src,_)) = do
                         M.insert src i extlinks }
               return i
   return [ mknode "w:hyperlink" [("r:id",id')] contents ]
-inlineToOpenXML opts (Image attr alt (src, tit)) = do
+inlineToOpenXML opts (Image attr alt (src, _)) = do
   -- first, check to see if we've already done this image
   pageWidth <- gets stPrintWidth
   imgs <- gets stImages
@@ -1149,12 +1151,13 @@ inlineToOpenXML opts (Image attr alt (src, tit)) = do
                               [ nvPicPr
                               , blipFill
                               , spPr ] ]
+          let altPlain = writePlain def $ B.doc $ B.para $ B.fromList alt
           let imgElt = mknode "w:r" [] $
                mknode "w:drawing" [] $
                  mknode "wp:inline" []
                   [ mknode "wp:extent" [("cx",show xemu),("cy",show yemu)] ()
                   , mknode "wp:effectExtent" [("b","0"),("l","0"),("r","0"),("t","0")] ()
-                  , mknode "wp:docPr" [("descr",tit),("id","1"),("name","Picture")] ()
+                  , mknode "wp:docPr" [("descr",altPlain),("id","1"),("name","Picture")] ()
                   , graphic ]
           let imgext = case mt >>= extensionFromMimeType of
                             Just x    -> '.':x