Comment 18 for bug 1840844

[Impact]

Before this change when a 403 error was encountered, such as failure to have the permission to perform an operation, the user would get logged out from UI pages written in the AngularJS framework. For example, if an admin user lacks the get_project permission and tries to access the
images page, project->compute->images, the 403 will forcibly log out the user.

This change keeps the user logged in when a 403 error is encountered and displays an error message. The change only affects AngularJS pages.

[Test Case]

* Create a new user without the get_project permission
* In the dashboard, access project->compute->images
* The user will get logged out

[Regression Potential]

* The patch changes the behavior of the Horizon code in response to a 403 error. The 403 in the original bug report was caused by a missing get_project permission. While unlikely it is possible that this change is incorrect under different error scenarios.