RST reader: apply .. class:: directly to following Header.

rather than creating a surrounding Div.

Closes #6699.

src/Text/Pandoc/Readers/RST.hs

@@ -758,7 +758,12 @@ directive' = do
             children <- case body of
                 "" -> block
                 _  -> parseFromString' parseBlocks  body'
-            return $ B.divWith attrs children
+            return $
+              case B.toList children of
+                [Header lev attrs' ils]
+                  | T.null body -> -- # see #6699
+                     B.headerWith (attrs' <> attrs) lev (B.fromList ils)
+                _ -> B.divWith attrs children
         other     -> do
             pos <- getPosition
             logMessage $ SkippedContent (".. " <> other) pos

test/command/6699.md

@@ -0,0 +1,13 @@
+```
+% pandoc -f rst -t native
+.. class:: allowframebreaks
+
+title
+-----
+
+text
+^D
+[Header 1 ("title",["allowframebreaks"],[]) [Str "title"]
+,Para [Str "text"]]
+```
+