Re: [PATCH v3] More friendly message when locking the index fails.

[Junio C Hamano <gitster@pobox.com>]

Matthieu Moy <Matthieu.Moy@imag.fr> writes:

> Just saying that index.lock exists doesn't tell the user _what_ to do
> to fix the problem. We should give an indication that it's normally
> safe to delete index.lock after making sure git isn't running here.
>
> Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
> ---
> Oops, I hadn't noticed, but the previous version triggered a warning
> because of lack of braces on the if. Sorry.

Perhaps it is a good idea to introduce

NORETURN void unable_to_lock_index_die(const char *path, int err)
{
	if (err == EEXIST)
	        die(...);
 	else
        	die(...);
}

in lockfile.c and call it from these two places you are touching?

>  builtin-update-index.c |   12 ++++++++++--
>  lockfile.c             |   13 +++++++++++--
>  2 files changed, 21 insertions(+), 4 deletions(-)
>
> diff --git a/builtin-update-index.c b/builtin-update-index.c
> index 5604977..23b97db 100644
> --- a/builtin-update-index.c
> +++ b/builtin-update-index.c
> @@ -742,8 +742,16 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
>  		if (newfd < 0) {
>  			if (refresh_flags & REFRESH_QUIET)
>  				exit(128);
> -			die("unable to create '%s.lock': %s",
> -			    get_index_file(), strerror(lock_error));
> +			if (lock_error == EEXIST) {
> +				die("Unable to create '%s.lock': %s.\n\n"
> +				    "If no other git process is currently running, this probably means a\n"
> +				    "git process crashed in this repository earlier. Make sure no other git\n"
> +				    "process is running and remove the file manually to continue.",
> +				    get_index_file(), strerror(lock_error));
> +			} else {
> +				die("Unable to create '%s.lock': %s",
> +				    get_index_file(), strerror(lock_error));
> +			}
>  		}
>  		if (write_cache(newfd, active_cache, active_nr) ||
>  		    commit_locked_index(lock_file))
> diff --git a/lockfile.c b/lockfile.c
> index 021c337..c812596 100644
> --- a/lockfile.c
> +++ b/lockfile.c
> @@ -158,8 +158,17 @@ static int lock_file(struct lock_file *lk, const char *path, int flags)
>  int hold_lock_file_for_update(struct lock_file *lk, const char *path, int flags)
>  {
>  	int fd = lock_file(lk, path, flags);
> -	if (fd < 0 && (flags & LOCK_DIE_ON_ERROR))
> -		die("unable to create '%s.lock': %s", path, strerror(errno));
> +	if (fd < 0 && (flags & LOCK_DIE_ON_ERROR)) {
> +		if (errno == EEXIST) {
> +			die("Unable to create '%s.lock': %s.\n\n"
> +			    "If no other git process is currently running, this probably means a\n"
> +			    "git process crashed in this repository earlier. Make sure no other git\n"
> +			    "process is running and remove the file manually to continue.",
> +			    path, strerror(errno));
> +		} else {
> +			die("Unable to create '%s.lock': %s", path, strerror(errno));
> +		}
> +	}
>  	return fd;
>  }
>  
> -- 
> 1.6.1.2.351.g80eb2.dirty
>
> --
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