Markdown raw HTML: fix handling of void hr element.

Closes #11793.

Added `voidTags` to unexported module
Text.Pandoc.Readers.HTML.TagCategories.

src/Text/Pandoc/Readers/HTML/TagCategories.hs

@@ -16,6 +16,7 @@ module Text.Pandoc.Readers.HTML.TagCategories
   , eitherBlockOrInline
   , epubTags
   , blockTags
+  , voidTags
   , sectioningContent
   , groupingContent
   )
@@ -68,6 +69,11 @@ epubTags = fromList ["case", "switch", "default"]
 blockTags :: Set Text
 blockTags = unions [blockHtmlTags, blockDocBookTags, epubTags]
 
+voidTags :: Set Text
+voidTags  = fromList
+  ["area", "base", "br", "col", "embed", "hr", "img", "input",
+   "link", "meta", "param", "source", "track", "wbr"]
+
 sectioningContent :: [Text]
 sectioningContent = ["article", "aside", "nav", "section"]
 

src/Text/Pandoc/Readers/Markdown.hs

@@ -50,6 +50,7 @@ import Text.Pandoc.Walk (walk)
 import Text.Pandoc.Parsing hiding (tableCaption)
 import Text.Pandoc.Readers.HTML (htmlInBalanced, htmlTag, isBlockTag,
                                  isInlineTag, isTextTag)
+import Text.Pandoc.Readers.HTML.TagCategories (voidTags)
 import Text.Pandoc.Readers.LaTeX (applyMacros, rawLaTeXBlock, rawLaTeXInline)
 import Text.Pandoc.Shared
 import Text.Pandoc.URI (escapeURI, isURI, pBase64DataURI)
@@ -1191,7 +1192,7 @@ rawHtmlBlocks = do
                  gobbleAtMostSpaces indentlevel
                  notFollowedBy' closer
                  block
-  contents <- if selfClosing
+  contents <- if selfClosing || tagtype `Set.member` voidTags
                  then return mempty
                  else mconcat <$> many block'
   result <-

test/command/11793.md

@@ -0,0 +1,9 @@
+```
+% pandoc -f markdown -t html
+<div><hr></div>
+^D
+<div>
+<hr>
+</div>
+```
+