HTML writer: use the ID prefix in the ID for the footnotes section.

In general, the ID prefix makes it possible to combine multiple pieces
of Pandoc-generated HTML with no possibility that IDs will conflict. One
exception to this was that the footnotes were always put into an element
like

    <aside id="foonotes" ...>

This commit applies the ID prefix to this ID as well.

src/Text/Pandoc/Writers/HTML.hs

@@ -299,7 +299,7 @@ pandocToHtml opts (Pandoc meta blocks) = do
     if null (stNotes st)
       then return mempty
       else do
-        notes <- footnoteSection EndOfDocument (stEmittedNotes st + 1) (reverse (stNotes st))
+        notes <- footnoteSection opts EndOfDocument (stEmittedNotes st + 1) (reverse (stNotes st))
         modify (\st' -> st'{ stNotes = mempty, stEmittedNotes = stEmittedNotes st' + length (stNotes st') })
         return notes
   st <- get
@@ -524,8 +524,8 @@ tableOfContents opts sects = do
 -- | Convert list of Note blocks to a footnote <div>.
 -- Assumes notes are sorted.
 footnoteSection ::
-  PandocMonad m => ReferenceLocation -> Int -> [Html] -> StateT WriterState m Html
-footnoteSection refLocation startCounter notes = do
+  PandocMonad m => WriterOptions -> ReferenceLocation -> Int -> [Html] -> StateT WriterState m Html
+footnoteSection opts refLocation startCounter notes = do
   html5 <- gets stHtml5
   slideVariant <- gets stSlideVariant
   let hrtag = if refLocation /= EndOfBlock
@@ -550,7 +550,7 @@ footnoteSection refLocation startCounter notes = do
                              ! A5.class_ className
                              ! A5.role "doc-endnotes"
                              $ x
-        | html5 = H5.aside   ! A5.id "footnotes"
+        | html5 = H5.aside   ! prefixedId opts "footnotes"
                              ! A5.class_ className
                              ! A5.role "doc-endnotes"
                              $ x
@@ -805,7 +805,7 @@ blockToHtmlInner opts (Div (ident, "section":dclasses, dkvs)
     if emitNotes
       then do
         st <- get
-        renderedNotes <- footnoteSection (writerReferenceLocation opts)
+        renderedNotes <- footnoteSection opts (writerReferenceLocation opts)
                            (stEmittedNotes st + 1) (reverse notes)
         modify (\st' -> st'{ stNotes = mempty,
                              stEmittedNotes = stEmittedNotes st' + length notes })
@@ -1084,7 +1084,8 @@ blockToHtml opts block = do
     then do
       notes <- if null (stNotes st)
         then return mempty
-        else footnoteSection (writerReferenceLocation opts) (stEmittedNotes st + 1) (reverse (stNotes st))
+        else footnoteSection opts (writerReferenceLocation opts)
+                             (stEmittedNotes st + 1) (reverse (stNotes st))
       modify (\st' -> st'{ stNotes = mempty, stEmittedNotes = stEmittedNotes st' + length (stNotes st') })
       return (doc <> notes)
     else return doc

test/command/4235.md

@@ -4,7 +4,7 @@ This.^[Has a footnote.]
 ^D
 <p>This.<a href="#foofn1" class="footnote-ref" id="foofnref1"
 role="doc-noteref"><sup>1</sup></a></p>
-<aside id="footnotes" class="footnotes footnotes-end-of-document"
+<aside id="foofootnotes" class="footnotes footnotes-end-of-document"
 role="doc-endnotes">
 <hr />
 <ol>