pgf-server HTTP mode feature: return the contents of index.html when the URL refers to a directory

src/server/ServeStaticFile.hs

@@ -1,9 +1,15 @@
 module ServeStaticFile where
 import System.FilePath
+import System.Directory(doesDirectoryExist)
 import Network.CGI(setHeader,outputFPS,liftIO)
 import qualified Data.ByteString.Lazy.Char8 as BS
 
 serveStaticFile path =
+  do b <- liftIO $ doesDirectoryExist path
+     let path' = if b then path </> "index.html" else path
+     serveStaticFile' path'
+
+serveStaticFile' path =
   do setHeader "Content-Type" (contentTypeFromExt (takeExtension path))
      outputFPS =<< liftIO (BS.readFile path)