Make the revision part percent-encoded in version control URLs

[kazssym]

This PR changes how the revision specification is handled in version control URLs. When a branch name contains special characters such as '@' or '#', they must be percent-encoded in URLs; however, this is not currently implemented.

Fixes #10226

[kazssym]

Attempting to fix #10226

[kazssym]

We need to add test cases.

[kazssym]

We need to add test cases.

Added.

[notatallshaw]

Thanks for the PR, it may take some time to review as maintainers capacity is very limited. A couple of quick questions:

1. Will a user need to change anything that currently works?
2. Can you give a very short example (say in the news entry), of something that previously wasn't possible but now will work?

[kazssym]

Thanks for the PR, it may take some time to review as maintainers capacity is very limited. A couple of quick questions:

1. Will a user need to change anything that currently works?
2. Can you give a very short example (say in the news entry), of something that previously wasn't possible but now will work?

The only case usage will change is when any revision or branch name has % characters, and those percents will have to be encoded as %25 then, although I don't know if it worked without the encoding previously.

Users must modify git+https://example.com/repo@some%branch to ...@some%25branch.

I will add a simple example later. Thanks.

[uranusjr]

Users must modify git+https://example.com/repo@some%branch to ...@some%25branch

We should call this out in the news/ file too. This will be included in the release notes.

[kazssym]

Updated the news entry with more details.

[ichard26]

@uranusjr since you were quite involved in the discussions on the associated issue, could you take a look at this PR? TIA!

[Copilot]

Pull Request Overview

This PR implements percent-encoding for revision specifications in version control URLs to properly handle branch names containing special characters like '@' and '#'. When these characters appear in branch names, they need to be URL-encoded to avoid conflicts with URL parsing.

• Adds percent-encoding of revision strings when constructing VCS URLs
• Adds percent-decoding of revision strings when parsing VCS URLs
• Includes comprehensive test coverage for the new encoding/decoding functionality

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/pip/_internal/vcs/versioncontrol.py	Implements percent-encoding/decoding for revision parts in VCS URLs
tests/unit/test_vcs.py	Adds test cases to verify proper handling of special characters in revisions
news/13407.bugfix.rst	Documents the bugfix and breaking change for users with '%' in branch names