[PATCH 1/8] am: handle "-h" argument earlier

If the user provides "-h" on the command line, then our parse_options() invocation will show a usage message and quit. But if "-h" is the only argument, the git wrapper behaves specially: it ignores our RUN_SETUP flag and calls cmd_am() without having done repository setup at all. This is due to 99caeed05 (Let 'git <command> -h' show usage without a git dir, 2009-11-09).

Before cmd_am() calls parse_options(), though, it runs a few other setup functions. One of these is am_state_init(), which uses git_pathdup() to set up the default rebase-apply path. But calling git_pathdup() when we haven't done repository setup will fall back to using ".git". That's mostly harmless (since we won't use the value anyway), but is forbidden since b1ef400eec ("setup_git_env: avoid blind fall-back to ".git"", 2016-10-20), and we now BUG().

We can't easily move that setup to after the parse_options() call; the point is to set up defaults that are overwritten by the option parsing. Instead, we'll detect the "-h" case early and show the usage then. This matches the behavior of other builtins which have a similar setup-ordering issue (e.g., git-branch).

Signed-off-by: Jeff King <peff@peff.net>
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 builtin/am.c | 3 +++
 1 file changed, 3 insertions(+)