Target field is escaped whenever Advanced Settings is revisited, causing it to get exponentially longer each time you save it if it started out with any non-alphanumeric characters

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 6.2.X EE, 7.0.X EE, Master
• Fix Version/s: 6.2.X EE, 7.0.0 DXP FP19, 7.0.3 CE GA4, 7.0.0 DXP SP4, 7.0.X EE, 7.1.X, Master
• Component/s: Performance, WCM, WCM > Sites Management > Pages Administration
• Labels:
  • 62-ee-sp20
  • liferay-digital-enterprise-70-sp4
  • liferay-fixpack-de-19-7010
  • liferay-fixpack-portal-152-6210
• Branch Version/s:
  7.0.x, 6.2.x
• Backported to Branch:
  Committed
• Story Points: 1
• Fix Priority: 4
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/49137

Description
Inside the Advanced Configuration settings for a Page, there is a Target field. If you put any non-alphanumeric characters in this field and click Save, the field will be escaped before it is saved. This causes the field to get exponentially longer with each successive save, leading to severe memory problems.

Steps to Reproduce

1. Navigate to Left-Hand Navigation Menu > Liferay > Navigation > Welcome > Configure > Advanced.
2. Enter some text that contains some non-alphanumeric characters in the target field (for instance, "This is a test" works because it has spaces), and click Save.
3. You will be taken away from the page; navigate back to the page.

Excpected Result: The text you entered will be displayed in the target field
Actual Result: The text you entered into the target field has been escaped. If you save it again, you'll see that it gets escaped even further. Each time you save it, the text gets exponentially longer as there are exponentially more characters that need to be escaped each time.

It should not be possible to keep making a piece of text longer and longer simply by clicking save. If you save it too many times, you'll be having memory problems.

Reproduced in master (74b1a2def1879cd4239386e2d73c38c176d32003)
Reproduced in ee-7.0.x (f18502eb716bc5a7f9933769fc87f3a55622ce7f)
Reproduced in ee-6.2.x (c78862e56bd1422bcf7c35ec169772fbc4380109)