From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 14 Jun 2016 17:50:55 GMT
Subject: Re: [PATCH v7 02/40] builtin/apply: make apply_patch() return -1 instead of die()ing
Message-ID: <xmqqlh27accg.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <CAP8UFD1zPUZQTY_rdMwK8vQBd7M5d8gPdTaEmfrg_Q74Y5B2Ew@mail.gmail.com>

Christian Couder <christian.couder@gmail.com> writes:

>> Before this patch, the program said "fatal: $message" and exited
>> with status = 128.  All these changes in this step modifies the
>> external behaviour and make it say "error: $message" and exit with
>> status = 1 (at least the caller in apply_all_patches() does so).
>>
>> Will that be an issue for the calling scripts?
>
> Hopefully the scripts don't check the specific error code and message.

The error codes are designed to be a vehicle that carries
information in a robust way, so it is perfectly understandable if
the callers used it to tell hopelessly broken input that caused
"die" and an otherwise sensible patch that does not happen to
apply.  Whoever is changing the external behaviour is responsible
for making sure the existing callers are not broken.

Hope is not a sound software engineering practice.