404 On Pull Request when branch has plus character

[fubarwrangler]

• Gitea version (or commit ref): 1.7.4
• Git version: 2.9.5 (on server)
• Operating system: RHEL7
• Database (use [x]):
  • PostgreSQL
  • MySQL
  • MSSQL
  • SQLite
• Can you reproduce the bug at https://try.gitea.io:
  • Yes (provide example URL)
    https://try.gitea.io/TestGanization/testando/compare/master...willsk:test++
  • No
  • Not relevant
• Log gist:

Description

If you have a branch with a plus sign in it (haven't tried other characters) which is legal in git (my client in Fedora didn't complain -- a colleague had a branch with 'c++' in the name), you can't make a pull request: as soon as you select the branch with the + in the name you get a 404.
...

Screenshots

--> (click on test++)

[zeripath]

See #6302 - I've listed a number of ways that the compare url is broken.

That being said rather than mark this issue as a duplicate - We could use this issue as the sub issue for dealing with url decomposition and creation affecting compare.

(There's several subissues to #6302 - including the actual issue that causes it which as yet is unidentified.)

[mrsdizzie]

It looks like this problem comes from:

gitea/routers/repo/pull.go

Line 636 in 7884353

infoPath, err = url.QueryUnescape(ctx.Params("*"))

QueryUnescape will turn a literal + into a blank space. Heres a test:
https://play.golang.org/p/i19lnB9Q7-M

I think we might want PathUnescape here:
https://golang.org/src/net/url/url.go?s=5107:5151#L173
Based on

// PathUnescape is identical to QueryUnescape except that it does not
// unescape '+' to ' ' (space).

[lunny]

If this is duplicated with #6302 , I think we can close this one.

[mrsdizzie]

This issue is separate and has a specific known cause (which will be fixed with PR #6334)