This looks like a Parsoid bug (or Mathoid or Math?). We're getting a <div> splitting the paragraph when display=inline.

Looks like this is related to T165115#3257961 and T165115#3257490.

I happened to see this behavior in Parsoid's visual diff run y'day ...

But, https://gerrit.wikimedia.org/r/#/c/353566/ may fix the problem as well. I haven't followed all the threads in the discussion yet.

In any case, before the reverted change in https://gerrit.wikimedia.org/r/#/c/353584/ is redeployed, we should verify that Parsoid isn't getting that div-wrapped output as part of action=parse, and if it is and that is expected, we should update Parsoid to strip that <div> tag.

This can be reproduced in the beta cluster https://en.wikipedia.beta.wmflabs.org/wiki/Selenium_Echo_link_test_0.7097762172580837?veaction=edit

Parsoid output snippet from https://en.wikipedia.beta.wmflabs.org/api/rest_v1/page/html/Selenium_Echo_link_test_0.7097762172580837 shows

<div class="mw-parser-output" typeof="mw:Extension/math" about="#mwt4" data-mw="{&quot;name&quot;:&quot;math&quot;,&quot;attrs&quot;:{},&quot;body&quot;:{&quot;extsrc&quot;:&quot;(G;\\cdot)&quot;}}" id="mwAw"><p><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML">
  <semantics>
    <mrow class="MJX-TeXAtom-ORD">
      <mstyle displaystyle="true" scriptlevel="0">
        <mo stretchy="false">(</mo>
        <mi>G</mi>
        <mo>;</mo>
        <mo>⋅<!-- ⋅ --></mo>
        <mo stretchy="false">)</mo>
      </mstyle>
    </mrow>
    <annotation encoding="application/x-tex">{\displaystyle (G;\cdot )}</annotation>
  </semantics>
</math></span><img src="//en.wikipedia.beta.wmflabs.org/api/rest_v1/media/math/render/svg/e860c64a53f7fd6199923771405c15f7e4b4287f" class="mwe-math-fallback-image-inline" aria-hidden="true" style="vertical-align: -0.838ex; width:5.369ex; height:2.843ex;" alt="{\displaystyle (G;\cdot )}"></span></p>

</div>

@mobrovac @Pchelolo @GWicke might be worth purging stored RB content since the Tue rollout. Any pages

• whose content refreshed in RB during these 3 days,
• contains inline math content
• hasn't been subsequently edited before a VE edit

might see a broken editing experience for inline math formulae.

This is a small subset of pages but if any editors encounter this issue ?action=purge will be a quick fix.

Mentioned in SAL (#wikimedia-operations) [2017-05-13T00:31:15Z] <urandom> T165139: Truncating RESTBase summary tables (corruption)

Mentioned in SAL (#wikimedia-operations) [2017-05-13T00:54:44Z] <urandom> T165139: Truncating RESTBase feed_aggregated tables (corruption)

Finding such a subset of pages is non-trivial. On the other hand, re-rendering (all) pages is also useless since the parser content fetched by Parsoid is fetched from cache, so until all of these have been either edited or null-edited there is not much we can do here at the moment.

You might try supplying an empty value for the new wrapoutputclass parameter to action=parse to suppress the wrapper, if that's what you're using.

Change 353707 had a related patch set uploaded (by Subramanya Sastry; owner: Subramanya Sastry):
[mediawiki/extensions/ParsoidBatchAPI@master] Disable parser output wrapper

https://gerrit.wikimedia.org/r/353707

Change 353709 had a related patch set uploaded (by Subramanya Sastry; owner: Subramanya Sastry):
[mediawiki/services/parsoid@master] T165139: Prevent <div> wrapping of action=parse output

https://gerrit.wikimedia.org/r/353709

Change 353707 merged by jenkins-bot:
[mediawiki/extensions/ParsoidBatchAPI@master] Disable parser output wrapper

https://gerrit.wikimedia.org/r/353707

Change 353709 merged by jenkins-bot:
[mediawiki/services/parsoid@master] T165139: Prevent <div> wrapping of action=parse output

https://gerrit.wikimedia.org/r/353709

This is now fixed in the beta cluster. https://en.wikipedia.beta.wmflabs.org/api/rest_v1/page/html/Selenium_Echo_link_test_0.9285218489365489 no longer has the <div> wrapper.

So, as long as the ParsoidBatchAPI patch above is deployed with the core patch, this won't break in production either.

@greg But, if the core patch is reverted from 1.30.0-wmf.2, the ParsoidBatchAPI patch above should also be reverted! Otherwise, you will see a lot of crashers in production.

Mentioned in SAL (#wikimedia-operations) [2017-05-22T20:46:44Z] <arlolra> Updated Parsoid to ebac1890 (T165139)