Reviewer cannot view specified commit changes when forked repository is private

[JamesZBL]

Describe the bug

Commiter A fork my repo and commit some changes, and create a pull request to me. As his repo is private, when I review the Pull Request from him and click a commit SHA-1, Gogs would show a "404" page. That's not what I want.

Gogs version or commit

0.11.96.1107

Git version

1.8.3.1

Operating system

CentOS 7

Database

SQLite

To Reproduce
Steps to reproduce the behavior:

1. Fork repo and make my own repo PRIVATE
2. Commit, push and create a PR
3. Reviewer go to 'Pull requests'
4. Reviewer click on one of 'SHA-1' in 'Commits'
5. See error '404'

Can you reproduce the bug at https://try.gogs.io?

https://try.gogs.io/zhengbaole_huice/pos-test/commit/67b2705c7542e13d8918d50f034743ec7214712a

Expected behavior

See file changes of that commit

Actual behavior

See error page

Screenshots

404

Additional context

No error log

[unknwon]

[JamesZBL]

https://try.gogs.io/zhengbaole_huice/pos-test/commit/67b2705c7542e13d8918d50f034743ec7214712a
@unknwon

[unknwon]

Do you have read access to the source repository?

[JamesZBL]

He forked my repository as his private repository, so I can't read his repository. I want just read one commit diff from his Pull Request, not the whole code repository.
Now, I can read all diff, so I thin I should also have permission to read one of commits.

[unknwon]

I think it does make sense you have 404 if you have no access to a private repository. It is undefined which commit you should be able to read without access to the repository itself.

[JamesZBL]

Now I can read ten commits in one page, so I have access to diff those commits. Why can't I have access to diff just one commit?

[unknwon]

Now I can read ten commits in one page

What is "one page"? Can you give a concrete example?