Editor: Quotation marks don't always close correctly

[siobhyb]

Quotation marks don't close correctly in the editor in cases where both of the following are true:

• The words in between the quotation marks are formatted e.g. they're bold, underlined, or italicised.

• The quotation marks are the last ones on the post/page.

This is especially noticeable in languages such as French, where angled quotes are used for quotation marks. Additionally, this isn't reproducible in cases where the quotation marks themselves have been included in the formatting, just when the words in between them have.

Examples:

HTML content to test with:
​https://cloudup.com/c6vhZ2dYTOG

We were able to reproduce this on WP.com (WP 4.2 alpha, using several different themes, and in French and English language) and then on a WP.org install (latest trunk, using Twenty Fifteen theme and English language).

[iseulde]

Happens in 4.1 too. Confirmed the problem for the last paragraph in the example.

[lancewillett]

I'm able to repeat, also, using the same test content — in trunk ((4.2-beta4-32057-src) with Twenty Fifteen theme.

[miqrogroove]

Duplicate of #18549.