Fix redirects modifying the host

What does this MR do?

This MR ensures that the redirect location is correctly constructed when redirecting from a URL in which the old path is a substring in the host.

Example of the bug

• Modify group with path lab to laboratory
• Visit https://gitlab.com/lab
• Get redirected to https://gitlaboratory.com/gitlab instead of https://gitlab.com/laboratory

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #32506

changed title from Fix #32506 to Fix redirects modifying the host

changed the description

added 1 commit

• 11f82de1 - Add test that fails without the fix

Compare with previous version

assigned to @mkozono

added 2 commits

• f9785dce - Fix ensure_canonical_path for top level routes
• 59256b5a - Refactor to more robust implementation

Compare with previous version

marked the checklist item Changelog entry added, if necessary as completed

marked the checklist item Documentation created/updated as completed

marked the checklist item API support added as completed

marked the checklist item Added for this feature/bug as completed

marked the checklist item Conform by the merge request performance guides as completed

marked the checklist item Conform by the style guides as completed

marked the checklist item Branch has no merge conflicts with master (if it does - rebase it please) as completed

changed the description

marked the checklist item Squashed related commits together as completed

assigned to @DouweM

assigned to @mkozono

resolved all discussions

added 1 commit

• 49697bc8 - Refactor to more robust implementation

Compare with previous version

assigned to @DouweM

Resolved conflicts with EE https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1944

approved this merge request

mentioned in commit 5d5e6954

merged

Picked into 9-2-stable will go into 9-2 RC7

mentioned in commit ee712af7