Git.ls_remote fails when stderr isn't empty

[serhii-shnurenko]

Subject of the issue

When the output of ls-remote command is parsed both stout and stderr parsed, what causes the script to fail because of the unexpected git command output.

Your environment

• git version 1.7.1, ruby-git 1.5.0
• ruby 2.5.3p105 (2018-10-18 revision 65156) [x86_64-linux]

Expected behaviour

Git.ls_remote working even if something fails into stderr.
Output to stderr parsed separately from stdout.
IDK how complicated is it, but why not switch Open3::popen3 as command runner?

Steps to reproduce

You should have output in stderr for your git command. Then Git.ls_remote will fail.

Actual behaviour

When running Git.ls_remote and stderr isn't empty, the parsing of ls-remote command will fail because warning in the output causes:

NoMethodError: undefined method `split' for nil:NilClass
  /opt/rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/git-1.5.0/lib/git/lib.rb:419:in `block (2 levels) in ls_remote'
  /opt/rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/git-1.5.0/lib/git/lib.rb:417:in `each'
  /opt/rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/git-1.5.0/lib/git/lib.rb:417:in `block in ls_remote'
  /opt/rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/git-1.5.0/lib/git/lib.rb:416:in `tap'
  /opt/rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/git-1.5.0/lib/git/lib.rb:416:in `ls_remote'
  /opt/rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/git-1.5.0/lib/git.rb:149:in `ls_remote'
....

The reason is that git commands on this host for some reason output warnings about hostkey everytime. And I still searching for the reasons, why ~/.ssh/known_hosts file in the home is ignored, but I believe that this kind of warnings shouldn't fail program execution.
When I running my script, I'm getting:

RSA host key for IP address '**********' not in list of known hosts.

Which then not splitted by the tabs because there are no tabs in this string

ruby-git/lib/git/lib.rb

Line 501 in e2fd4af

(sha, info) = line.split("\t")

I checked the output of the command manually with and without stderr redirection to the /dev/null. as we can see with suppressed stderr script will not fail.

[serhii@host ~] :) git ls-remote 'ssh://git@*********:*****/******.git'
RSA host key for IP address '**********' not in list of known hosts.
5992e82a52648a6348e42bad853ee32ae06d4c5a	HEAD
249d61415a4ea902e453ebb3868835b9e340fc71	refs/heads/**********
4d50c9c33c15e96333f0543a53ae5599b8e7c0a9	refs/heads/alpha/develop
5992e82a52648a6348e42bad853ee32ae06d4c5a	refs/heads/master
c7fdfcd41cab3c419d3b8f94977b395bef25fabf	refs/heads/************

[serhii@host ~] :) git ls-remote 'ssh://git@*********:*****/******.git' 2>/dev/null
5992e82a52648a6348e42bad853ee32ae06d4c5a	HEAD
249d61415a4ea902e453ebb3868835b9e340fc71	refs/heads/**********
4d50c9c33c15e96333f0543a53ae5599b8e7c0a9	refs/heads/alpha/develop
5992e82a52648a6348e42bad853ee32ae06d4c5a	refs/heads/master
c7fdfcd41cab3c419d3b8f94977b395bef25fabf	refs/heads/************

P.S.: Also wondering why ls_remote doesn't support listing tags, but that's another issue.

[stale]

A friendly reminder that this issue had no activity for 60 days.

[jcouball]

Fixed with #684 and released in git-2.0.0-pre1