<p>I ran into this problem when I was writing a rather long reply to another mapper's message. I have drafted my message with <a href="https://daringfireball.net/projects/markdown/" rel="nofollow">original Markdown</a>; but when I previewed the message before sending, I found several problems with <a href="https://www.openstreetmap.org/" rel="nofollow">OpenStreetMap.org</a>'s Markdown implementation around its interpretation of nested numbered/bullet list.</p>
<p>This resulted in me having fumble for several minutes to find <em>partial</em> workaround (see below), before I could actually send the message in a relatively unmangled form.</p>
<p>Exact steps to reproduce:</p>
<ul>
<li>Start a browser with a new private browsing session (or with cookies cleared) and JavaScript enabled.</li>
<li>Visit your own OSM user page as anonymous user.</li>
<li>Click <em>Send Message</em>.</li>
<li>You will be prompted to log in: enter your OSM user and password.</li>
<li><q>Send a new message</q> page will appear.</li>
<li>Enter <code>These are nested lists...</code> in the <em>Subject</em> field.</li>
<li><strong>Copy</strong> text from <a href="https://gist.githubusercontent.com/nachanon/320b8a0473ac0658a8f2fe8ddd9da6c7/raw/8c94d376792af491c71795a2f225e5212ed046eb/nestedlist.md" rel="nofollow">this Gist</a> <strong>and paste</strong> it into the <em>Body</em> field. (Warning: Tab indentation on blank lines are totally intended)</li>
<li>Click the <em>Preview</em> button.</li>
</ul>
<p>The preview would show something like this:<br>
<a target="_blank" rel="noopener noreferrer" href="https://camo.githubusercontent.com/f7fb3f4d60c7adc7e6ec97b5d9f82342b8759afb/687474703a2f2f752e6375626575706c6f61642e636f6d2f7877696e646f77732f5a4d6f6761342e706e67"><img src="https://camo.githubusercontent.com/f7fb3f4d60c7adc7e6ec97b5d9f82342b8759afb/687474703a2f2f752e6375626575706c6f61642e636f6d2f7877696e646f77732f5a4d6f6761342e706e67" alt="" data-canonical-src="http://u.cubeupload.com/xwindows/ZMoga4.png" style="max-width:100%;"></a></p>
<p>Then, compare it to an output from <a href="https://daringfireball.net/projects/markdown/" rel="nofollow">the original Markdown</a>:<br>
<a target="_blank" rel="noopener noreferrer" href="https://camo.githubusercontent.com/58375f475c1f4eaaa53a00b080250a55ecb76504/687474703a2f2f752e6375626575706c6f61642e636f6d2f7877696e646f77732f307166334f4c2e706e67"><img src="https://camo.githubusercontent.com/58375f475c1f4eaaa53a00b080250a55ecb76504/687474703a2f2f752e6375626575706c6f61642e636f6d2f7877696e646f77732f307166334f4c2e706e67" alt="" data-canonical-src="http://u.cubeupload.com/xwindows/0qf3OL.png" style="max-width:100%;"></a></p>
<p>You would see that on OSM messaging interface...</p>
<ul>
<li><em>Bullet</em> lists that are nested inside numbered list <strong>are mistakenly displayed as <em>numbered</em> lists</strong>. <strong>(No workaround)</strong></li>
<li>Sub lists with <em>equally-indented</em> blank lines before and after them <strong>are mistakenly displayed as code snippet <em>and</em> excluded from the list</strong>. (Workaround: remove these lines before sending the message)</li>
</ul>
<p>Please investigate and fix.</p>
<p>Browser: Opera 11.64 (Win32)<br>
System: Microsoft Windows XP Professional SP3</p>
<h3>Notes</h3>
<ul>
<li>This is not specific to preview: the same message sent to myself also exhibit the same problem when viewed in the on-site inbox.</li>
<li>This is not specific to browser: result obtained from Pale Moon 25.8.1 (GNU/Linux 32-bit) is the same.</li>
<li>The word <em>Markdown</em> on the messaging page's help panel actually links to <a href="https://daringfireball.net/projects/markdown/" rel="nofollow">the original Markdown</a>. So, compatibility is expected.</li>
</ul>

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