[BUG?] `config branch.autosetuprebase true` breaks `rev-parse --is-inside-work-tree`

Dear all,

I am not sure if this is an actual bug or just a corner case that's not worth to be fixed.

This was not tested with HEAD or even 2.1.2, but 2.1.1.

Notwithstanding if the setting is correct, shouldn't rev-parse be resilient enough to at least be able to tell if we're in a work tree? I understand why `git status` and the like would need to parse the full config, but determining if you're in a work tree should be possible in most if not all cases. Unless detached work trees get you into a situation where you really need to parse the whole config...

So this is not a real bug report, more of a "is this intended this way?"

As you can see, my custom prompt (via vcs_info in Zsh) breaks due to that which is how I noticed.

richih@titanium ~ % mkdir git_test richih@titanium ~ % cd git_test richih@titanium ~/git_test % git init Initialized empty Git repository in /home/richih/git_test/.git/ richih@titanium (git)-[master] ~/git_test % git rev-parse --is-inside-work-tree true richih@titanium (git)-[master] ~/git_test % git config branch.autosetuprebase true richih@titanium ~/git_test % git rev-parse --is-inside-work-tree error: Malformed value for branch.autosetuprebase fatal: bad config file line 8 in .git/config richih@titanium ~/git_test % cat .git/config [core] repositoryformatversion = 0 filemode = true bare = false logallrefupdates = true [branch] autosetuprebase = true richih@titanium ~/git_test % git --version git version 2.1.1 richih@titanium ~/git_test %

Thanks, Richard

Richard Hartmann <richih.mailinglist@gmail.com> writes:

It does not seem to be limited to rev-parse but having a malformed configuration for that variable would break everything Git, which certainly is not how it is supposed to work. It also seems that the breakage dates back very far into the past (I checked 1.7.0 and it seems to be broken the same way).

The same breakage exists for branch.autosetupmerge, I think, e.g.

	[branch]
                autosetupmerge = garbage

In config.c, git_default_branch_config() must be corrected to set git_branch_track and autorebase to BRANCH_TRACK_MALFORMED and AUTOREBASE_MALFORMED and the users of these two variables must be fixed to deal with the "malformed in the configuration" cases, I think. The error should happen only in the codepath where we need the value, and no other places.

Junio C Hamano <gitster@pobox.com> writes:

Having said that, given that any call git_config_bool() inside a callback function given to the git_config() will stop Git from doing anything even if the variable with a malformed value in quesiton is not used by the operation at all, and there are very many of them (e.g. setting core.filemode to "treu" would break everything), it appears to me that:

 (1) it could be argued that catching obvious typos in the
     configuration file as early as possible, even if the variables
     with typos are not used for the particular operation, is even a
     feature, as long as you can fix the brekage with "git config"
     (and/or your editor);

 (2) it is too much pain to shift the error checking to the site of
     their use from the site of their parsing anyway ;-)

And I suspect Tanay and Matthieu's recent work is taking us to a direction where many code paths do not use the config callbacks (which is what leads us to detect errors at parse time even for variables that are not used) and instead allow the callers that care about the individual variables to diagnose errors at the site of use. So as you stated originally, this may not be something we want to patch up in the current callback based config system.

On 10/8/2014 11:05 PM, Junio C Hamano wrote:

Supporting Junio's claim, there is a function called git_default_config() which checks and sets a whole load of config values which may or maynot be relevant to the codepath that called it. (branch.autosetuprebase is a part of it) So an error may occur printing a seemingly unrelated config value as the malformed variable as happened in your case.

There are currently 72 callers of git_default_config() in the codebase, so a malformed config value breaks most of git commands. The only path to correct this behavior would be either correct the config variable in the file or we could decouple the huge monolithic function that git_default_config() has become and use the git_config_get_value() in the code paths that really need them. This part is doable, albeit slowly. All the config variables in git_default_config() can be rewritten using the new non callback based functions easily as demonstrated in an earlier RFC patch.

On Wed, Oct 08, 2014 at 01:22:33PM +0200, Richard Hartmann wrote:

I have seen similar problems where various git commands fail in the middle if a config file is the subject of merge conflicts. For example:

  vauxhall ok % git pull . master
  From .
   * branch            master     -> FETCH_HEAD
  Auto-merging .zshrc
  CONFLICT (content): Merge conflict in .zshrc
  Auto-merging .zshenv
  CONFLICT (content): Merge conflict in .zshenv
  Auto-merging .vimrc
  Auto-merging .gitconfig
  CONFLICT (content): Merge conflict in .gitconfig
  fatal: bad config file line 9 in .gitconfig

This tends to be one of the downsides of storing one's dotfiles in git. I usually work around it by specifying HOME=/tmp before a command I think might cause a conflict in .gitconfig. I'm not sure there's any good way around it, though.