From: Ronnie Sahlberg <sahlberg@google.com>
Date: Wed, 18 Jun 2014 21:40:00 GMT
Subject: Re: [PATCH v18 10/48] refs.c: verify_lock should set errno to something meaningful
Message-ID: <CAL=YDWnkXZFYMSRz9y-d5aRN8a-aaWPi1DiyPgGczM0Cb_eW5g@mail.gmail.com>
In-Reply-To: <53A1F8BD.4060203@alum.mit.edu>

fixed in 19

On Wed, Jun 18, 2014 at 1:38 PM, Michael Haggerty <mhagger@alum.mit.edu> wrote:
> On 06/17/2014 05:53 PM, Ronnie Sahlberg wrote:
>> Making errno when returning from verify_lock() meaningful, which
>> should almost but not completely fix
>>
>>  * a bug in "git fetch"'s s_update_ref, which trusts the result of an
>>    errno == ENOTDIR check to detect D/F conflicts
>>
>> ENOTDIR makes sense as a sign that a file was in the way of a
>> directory we wanted to create.  Should "git fetch" also look for
>> ENOTEMPTY or EEXIST to catch cases where a directory was in the way
>> of a file to be created?
>>
>> Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
>> ---
>>  refs.c | 4 ++++
>>  refs.h | 6 +++++-
>>  2 files changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/refs.c b/refs.c
>> index 9ea519c..a48f805 100644
>> --- a/refs.c
>> +++ b/refs.c
>> @@ -1932,18 +1932,22 @@ int refname_match(const char *abbrev_name, const char *full_name)
>>       return 0;
>>  }
>>
>> +/* This function should make sure errno is meaningful on error */
>>  static struct ref_lock *verify_lock(struct ref_lock *lock,
>>       const unsigned char *old_sha1, int mustexist)
>>  {
>>       if (read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
>> +             int save_errno = errno;
>>               error("Can't verify ref %s", lock->ref_name);
>>               unlock_ref(lock);
>> +             errno = save_errno;
>>               return NULL;
>>       }
>>       if (hashcmp(lock->old_sha1, old_sha1)) {
>>               error("Ref %s is at %s but expected %s", lock->ref_name,
>>                       sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
>>               unlock_ref(lock);
>> +             errno = EBUSY;
>>               return NULL;
>>       }
>>       return lock;
>> diff --git a/refs.h b/refs.h
>> index 82cc5cb..af4fcdc 100644
>> --- a/refs.h
>> +++ b/refs.h
>> @@ -137,11 +137,15 @@ extern int ref_exists(const char *);
>>   */
>>  extern int peel_ref(const char *refname, unsigned char *sha1);
>>
>> -/** Locks a "refs/" ref returning the lock on success and NULL on failure. **/
>> +/*
>> + * Locks a "refs/" ref returning the lock on success and NULL on failure.
>> + * On failure errno is set to something meaningfull.
>
> s/meaningfull/meaningful/
>
>> + */
>>  extern struct ref_lock *lock_ref_sha1(const char *refname, const unsigned char *old_sha1);
>>
>>  /** Locks any ref (for 'HEAD' type refs). */
>>  #define REF_NODEREF  0x01
>> +/* errno is set to something meaningful on failure */
>>  extern struct ref_lock *lock_any_ref_for_update(const char *refname,
>>                                               const unsigned char *old_sha1,
>>                                               int flags, int *type_p);
>>
>
>
> --
> Michael Haggerty
> mhagger@alum.mit.edu
> http://softwareswirl.blogspot.com/