`git-upload-pack` strips leading `/` only when single-quoted

[ninewise]

• Gitea version (or commit ref): v1.12.2
• Git version: 2.26.2
• Operating system: Alpine Linux
• Database (use [x]):
  • PostgreSQL
  • MySQL
  • MSSQL
  • SQLite

Description

Creating this issue for a friend without github.

This line replaces first ocurrence of '/ with ' from parameter. This works for cloning the repository with git over SSH, as the remote command gets executed as git-upload-pack '/user/repo' (strace shows this clearly). In that case, said function rewrites it to git-upload-pack 'user/repo' and later on it gets correctly split in user and repo. Now, there are other implementations of Git which doesn't send the commands in that precise way, but as command git-upload-pack with parameter /user/repo (note no single-quotes). Got is one of such implementations, which can't clone the repo as it fails here.

I think the intended behaviour is to remove any leading / from the parameter, quoted or not. Most correct solution would be using a shell quoting library to normalize the input and then remove the leading /. Alternatively, for a quick fix, removing the replace in parseCmd and changing line 144 to also trim / should do the trick.

[zeripath]

The approach in #12554 would probably help fix this.

[ninewise]

I don't think that will work. That code only deals with ", which I guess is well-defined in unified diff format. However, this case has to deal with shell quoting. I still believe that it'll be best to do proper shell parsing. If that's too invasive, I think the second-best approach will be teaching Gitea to with both single, double and unquoted parameters.

[CL-Jeremy]

@zeripath I think this PR broke clone via SSH completely... I actually found myself unable to clone anything via SSH on my own server the same day the PR was merged (which coincidentally had master merged in right on this commit), but thought it was my own mistake in configuration. I've just tried on try.gitea.io and got this:

02:11:41.343266 run-command.c:663       trace: run_command: unset GIT_DIR; ssh git@try.gitea.io 'git-upload-pack '\''CL-Jeremy/test-mirror.git'\'''
fatal: 'CL-Jeremy/test-mirror.git' does not appear to be a git repository
Gitea: Internal error
Failed to execute git command: exit status 128

[CL-Jeremy]

🆗 fixed in #12668