Re: [PATCH 1/3] git-branch: add --track and --no-track options

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Mar 5, 2007, 18:37 UTC
Message-ID: <Pine.LNX.4.63.0703051930560.22628@wbgn013.biozentrum.uni-wuerzburg.de>
In-Reply-To: <45EC51C6.5080505@lu.unisi.ch>

Hi,

On Mon, 5 Mar 2007, Paolo Bonzini wrote:

Show 8 quoted lines

> > Yes, you also check real_ref instead of checking if dwim_ref() 
> > returned 0. I feel a little bit uneasy about that, since there is no 
> > guarantee that these values are left untouched, whereas the return 
> > value is guaranteed to behave as expected.
> 
> There is.  The man page says "Scanning stops when an input character 
> does not match such a format character."  Scanning includes not 
> processing %n elements, either.

So, if you want to be that precise, it never says that it does not touch the pointers passed to it. But it states very clearly what the return value is in case of a failure.

Show 8 quoted lines

> Regarding dwim_ref, dwim_ref says:
> 
> int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
> {
>         const char **p, *r;
>         int refs_found = 0;
> 
>         *ref = NULL;

Yes, this is what the source does. But again, the return value is what you should -- and indeed forever can -- rely on. I am not really happy that dwim_ref() touches ref, even if nothing was found, but it is an _implementation detail_.

Show 6 quoted lines

> > I also feel a little uneasy about having to parse a format in order to 
> > parse a string, when you know what that string should look like. For 
> > example, you could make the code even more compact by asking "(p = 
> > strstr(value, "/*:refs/remotes/"))".
> 
> Go down this way and you will say that printf is useless too.

Nah. You are not fair.

Ciao, Dscho