Markdown reader: fix parsing of inline math (`$...$`) (#11348)

Do not allow blank lines before closing `$` delimiter.
This brings the parser in line with the documentation.

Closes #11311.

1 files changed, 61 insertions, 0 deletions

diff --git a/test/command/11348.md b/test/command/11348.md
new file mode 100644
index 000000000..1871808fe
--- /dev/null
+++ b/test/command/11348.md
@@ -0,0 +1,61 @@
+```
+% pandoc -f markdown -t native
+$ invalid opening inline math$
+
+$
+invalid opening inline math$
+
+$invalid closing inline math $
+
+$invalid closing inline math
+$
+
+$valid inline math$
+^D
+[ Para
+    [ Str "$"
+    , Space
+    , Str "invalid"
+    , Space
+    , Str "opening"
+    , Space
+    , Str "inline"
+    , Space
+    , Str "math$"
+    ]
+, Para
+    [ Str "$"
+    , SoftBreak
+    , Str "invalid"
+    , Space
+    , Str "opening"
+    , Space
+    , Str "inline"
+    , Space
+    , Str "math$"
+    ]
+, Para
+    [ Str "$invalid"
+    , Space
+    , Str "closing"
+    , Space
+    , Str "inline"
+    , Space
+    , Str "math"
+    , Space
+    , Str "$"
+    ]
+, Para
+    [ Str "$invalid"
+    , Space
+    , Str "closing"
+    , Space
+    , Str "inline"
+    , Space
+    , Str "math"
+    , SoftBreak
+    , Str "$"
+    ]
+, Para [ Math InlineMath "valid inline math" ]
+]
+```