Org reader: allow multi-word arguments to src block params

The reader now correctly parses src block parameter list even if
parameter arguments contain multiple words.

Closes: #3477

src/Text/Pandoc/Readers/Org/Blocks.hs

@@ -589,9 +589,12 @@ blockOption = try $ do
 orgParamValue :: Monad m => OrgParser m String
 orgParamValue = try $
   skipSpaces
-    *> notFollowedBy (char ':' )
-    *> many1 nonspaceChar
+    *> notFollowedBy orgArgKey
+    *> noneOf "\n\r" `many1Till` endOfValue
     <* skipSpaces
+ where
+  endOfValue = lookAhead $  (try $ skipSpaces <* oneOf "\n\r")
+                        <|> (try $ skipSpaces1 <* orgArgKey)
 
 
 --

test/Tests/Readers/Org.hs

@@ -1559,6 +1559,15 @@ tests =
             params = [ ("data-org-language", "sh"), ("startFrom", "10") ]
         in codeBlockWith ("", classes, params) ":() { :|:& };:\n"
 
+      , "Source block with multi-word parameter values" =:
+        unlines [ "#+BEGIN_SRC dot :cmdline -Kdot -Tpng "
+                , "digraph { id [label=\"ID\"] }"
+                , "#+END_SRC"
+                ] =?>
+        let classes = [ "dot" ]
+            params = [ ("cmdline", "-Kdot -Tpng") ]
+        in codeBlockWith ("", classes, params) "digraph { id [label=\"ID\"] }\n"
+
       , "Example block" =:
            unlines [ "#+begin_example"
                    , "A chosen representation of"