Org reader: Fix treatment of id property under heading.

Cloess #9639.

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

@@ -16,7 +16,7 @@ module Text.Pandoc.Readers.Org.DocumentTree
   ) where
 
 import Control.Arrow ((***), first)
-import Control.Monad (guard)
+import Control.Monad (guard, mplus)
 import Data.List (intersperse)
 import Data.Maybe (mapMaybe)
 import Data.Text (Text)
@@ -317,10 +317,12 @@ propertiesToAttr properties =
   let
     toTextPair = fromKey *** fromValue
     customIdKey = toPropertyKey "custom_id"
+    idKey = toPropertyKey "id"
     classKey    = toPropertyKey "class"
     unnumberedKey = toPropertyKey "unnumbered"
-    specialProperties = [customIdKey, classKey, unnumberedKey]
-    id'  = maybe mempty fromValue . lookup customIdKey $ properties
+    specialProperties = [customIdKey, idKey, classKey, unnumberedKey]
+    id'  = maybe mempty fromValue $
+              (lookup customIdKey properties `mplus` lookup idKey properties)
     cls  = maybe mempty fromValue . lookup classKey    $ properties
     kvs' = map toTextPair . filter ((`notElem` specialProperties) . fst)
            $ properties

test/command/9639.md

@@ -0,0 +1,11 @@
+```
+% pandoc -f org -t native
+#+title: repro
+
+* heading-name
+:PROPERTIES:
+:ID:       123abc
+:END:
+^D
+[ Header 1 ( "123abc" , [] , [] ) [ Str "heading-name" ] ]
+```