[MPlayer-dev-eng] [PATCH] replacement for internal mpg123 fork (mp3lib)

[Uoti Urpala]

On Thu, 2010-05-13 at 02:25 +0200, Thomas Orgis wrote:
> Am Thu, 13 May 2010 02:41:08 +0300
> schrieb Uoti Urpala <uoti.urpala at pp1.inet.fi>: 
> 
> > Well it also assumes that nobody will ever create an ABI-incompatible
> > version with a different value for the flag.
> 
> Well, the policy of the mpg123 project is not to do that. If any such
> incompatible change would come up, at least the soversion of the
> library would increase without backwards compatibility.
> And, well... anyone can produce a bastardized variant of the library
> that breaks existing binaries... as well as produce a manipulated
> header.

Creating an incompatible version with the same soname and breaking
existing binaries would be unreasonable, and trying to write things so
that they'd work even in that case is mostly pointless. But creating an
API-compatible version with a different ABI and soname is more
reasonable.

> > > or do more elaborate testing in configure for the certain features. Just
> > > tell me what you prefer. This particular feature (which is highly
> > > desirable for resync) entered libmpg123 with mpg123 version 1.3.0 .
> > 
> > That's fairly old right? Just not supporting older versions could be OK.
> > Also at least the mpg123.h in Debian seems to have a version number
> > #define. If that was present in earlier versions of mpg123 shouldn't it
> > allow a direct #if without any configure checks?
> 
> The version symbol is an idea that occured only for the 1.12 release,
> long after introducing that feature. You can get a version check through
> pkg-config, though... but Diego voiced dislike of that mechanism.

I'm generally in favor of using pkg-config for checks, but trying to
determine whether to use the call or not based on that would still
require extra complexity to transmit the information from configure (I'm
not sure whether you're talking about using the check to limit features
used like my comment about #if was, or about rejecting older versions
completely). Anyway I'd say just require a newer version.