Page freezes when long alphanumeric strings are pasted into a Blogs editor

• Type: Regression Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: Master
• Fix Version/s: 7.3.X, 7.3.5 CE GA6, 7.3.10 DXP GA1, Master
• Component/s: Alloy Editor
• Labels:
  • frontend
• Branch Version/s:
  7.3.x
• Backported to Branch:
  Committed
• Story Points: 1
• Fix Priority: 5
• Last Working Version:
  7.3.4 CE GA5
• Git Pull Request: https://github.com/liferay-frontend/liferay-portal/pull/323

There are very obvious performance issues when pasting long alphanumeric strings into a Blogs editor.

Steps to reproduce:

1. Add a blog entry
2. In the content field of the Blogs editor, paste some string with no spaces like Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch

• This is not reproducible when all pasted texts are short enough, like

  testtesttest testtesttesttesttest testtesttest 

  , but reproducible when any string is too long, like

  test test test testtesttesttesttesttesttesttesttesttesttest test test 

• This is also not reproducible with special characters, so URLs are pasted fine

Expected result:
The string is pasted immediately.

Actual result:
Page freezes.

No errors appear in the browser or portal console.

Reproduced on:
Tomcat 9.0.33 + MySQL 5.7.
Portal master-private 9ca74bd4ffb9fb2efc8d1c43d0b2cc64364648d0
Chrome 84 / Incognito
Firefox 79

Unable to reproduce on:
7.3 CE GA5