DocBook reader: add empty title to admonition div if not present.

This allows admonition elements (e.g. `<note>`) to work with
gfm admonitions even if the `<title>` is not present.

Closes #9569.

2 files changed, 22 insertions, 2 deletions

diff --git a/src/Text/Pandoc/Readers/DocBook.hs b/src/Text/Pandoc/Readers/DocBook.hs
index 7b4d1cb1b..68f55c219 100644
--- a/src/Text/Pandoc/Readers/DocBook.hs
+++ b/src/Text/Pandoc/Readers/DocBook.hs
@@ -1108,8 +1108,9 @@ parseBlock (Elem e) =
            -- the title: docbook references are ambiguous on that, and some implementations of admonitions
            -- (e.g. asciidoctor) just use an icon in all cases. To be conservative, we don't
            -- include the label and leave it to styling.
-           title <- case filterChild (named "title") e of
-                        Just t  -> divWith ("", ["title"], []) . plain <$> getInlines t
+           title <- divWith ("", ["title"], []) . plain <$>
+                    case filterChild (named "title") e of
+                        Just t  -> getInlines t
                         Nothing -> return mempty
            -- this will ignore the title element if it is present
            b <- getBlocks e
diff --git a/test/command/9569.md b/test/command/9569.md
new file mode 100644
index 000000000..edbe2e33d
--- /dev/null
+++ b/test/command/9569.md
@@ -0,0 +1,19 @@
+```
+% pandoc -f docbook -t gfm
+<note>
+  <para>Some content</para>
+</note>
+<para>Spacer.</para>
+<note>
+  <title>A note with a title. Works, but the title is discarded.</title>
+  <para>Some content</para>
+</note>
+^D
+> [!NOTE]
+> Some content
+
+Spacer.
+
+> [!NOTE]
+> Some content
+```