SAML provider connection can save with an invalid metadata url when edited

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: 7.0.X
• Fix Version/s: 7.0.X, 7.2.X, Master
• Component/s: Application Security > SAML
• Labels:
  • liferay-saml-2.0-provider-3.1.0
• Branch Version/s:
  7.2.x, 7.0.x
• Backported to Branch:
  Committed
• Fix Priority: 4
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal-ee/pull/18484

Steps to reproduce 

1. Configure and enable IdP
2. Configure SP
   • Do not enable after configuring
   • Make sure to use valid IdP metadata url
3. Change metadata url to something invalid and save
   • This should cause an error
4. Change metadata url back to the valid value
5. Navigate to IdP
6. Configure Service Provider Connection
   • Make sure to use valid SP metadata url
7. Change metadata url to something invalid and save
   • This should cause an error

Expected result:
Errors happen as described above.

Actual result:
The configuration saves and the following warning shows up in console:

WARN  [http-nio-9080-exec-4][MetadataUtilImpl:117] Unable to get SAML metadata from http://localhost:10080/c/portal/saml/metadata: Connection refused (Connection refused)

Reproduced on:
Tomcat 8.0.32 + MySQL 5.7.17. 
Portal 7.0.x-private GIT ID: e77b694bc647fdd19e0ebbacd41d6d7fa7ac4868