User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36

Steps to reproduce:

Try with this html:
<ol>
<li>line 1</li>
<li>line 2</li>
<ol>
<li>line 2.1</li>
</ol>
<li>line 3</li>
</ol>

Actual results:

It shows:

1. line 1
2. line 2
3. line 2.1
4. line 3 <----------------------- here it is wrong, it should show "3. line 3"

Expected results:

Tried on IE, Edge, Chrome, got the same expected result:

1. line 1
2. line 2
3. line 2.1
4. line 3

Hmm, the bug tool totally masses up my text. Let me describe like this:

Acutal result (I added "|" before each line to avoid markdown auto correct it):

|1. line 1
|2. line 2
| 1. line 2.1
|2. line 3 <----------------------- here it is wrong, it should show "3. line 3"

I tested this issue on:

Windows 10 64bit
Ubuntu 18.04.2 64bit
MacOs 10.14 64bit

Nigthly 70.0a1 affected on all Os
Beta 69.0b10 affected on all Os
Release 68.0.1 affected on all Os

That is invalid markup, for what is worth, and it behaves the same as CSS counters. The <ol> should be inside the <li>.

(But yeah, this is an issue that we may want to address, depending on how the various spec issues go)

I don't feel this is a dup of 1548753 since this bug doesn't require any CSS style and it can repro with such a common case. I hope this can be fixed asap.

It is a dupe of that bug, though.

The test-case in bug 1548753 comment 0 doesn't need any CSS either. List items use CSS internally.

The patch regressing both was the switch of list items to CSS counters, as the css-list spec defines. That is why our behavior now matches the behavior of CSS counters.

Maybe I'm missing something ablut how this bug is different to bug 1548753 comment 0 though?