Re: Git 2.8.1 fails test 32 of t7300-clean.sh, breaks profile build

Thanks for fixing the missing SANITY prerequisite Stefan.

As for the error handling logic in setup.c: is_nonbare_repository_dir (was clean.c: is_git_repository) my reasoning is as follows:

READ_GITFILE_ERR_STAT_FAILED READ_GITFILE_ERR_NOT_A_FILE:

When checking random paths for .git files these are the common error modes, file is not there or it is a directory. This should not be interpreted as a valid .git file.

READ_GITFILE_ERR_OPEN_FAILED READ_GITFILE_ERR_READ_FAILED:

Here we found a .git file but could not open and read it to verify that it is valid. Treating it as valid is the safest option for clean. For resolve_gitlink_ref I think it maybe leads to the creation of a redundant ref cache entries but I don't think this is a problem unless someone has a huge amount of unreadable .git files lying around.

READ_GITFILE_ERR_TOO_LARGE:

File is absurdly large (1MB), very unlikely to be a valid .git file.

READ_GITFILE_ERR_INVALID_FORMAT READ_GITFILE_ERR_NO_PATH:

File is malformed in some way, either the "gitdir:" prefix is missing or the path is missing. Could theoretically be a corrupted .git file but seems unlikely.

READ_GITFILE_ERR_NOT_A_REPO:

This is maybe a bit more suspicious. Here we have found a .git file, it has the format "gitdir: some/path" but is_git_directory("some/path") returned false, meaning that "some/path" does not fulfill:

/*
 * Test if it looks like we're at a git directory.
 * We want to see:
 *
 *  - either an objects/ directory _or_ the proper
 *    GIT_OBJECT_DIRECTORY environment variable
 *  - a refs/ directory
 *  - either a HEAD symlink or a HEAD file that is formatted as
 *    a proper "ref:", or a regular file HEAD that has a properly
 *    formatted sha1 object name.
*/

Technically we don't have a valid .git file here but we have something that really tries to be. I guess it is debatable what the correct conservative choice is here and if it is the same for all callers.

/Erik