[MPlayer-dev-eng] [PATCH] fix for unconditional use of PATH_MAX

[Fabien Tassin]

According to Robert Millan:
> 
> POSIX describes PATH_MAX, but it is left optional to implementors wether
> it is defined or not.(I can search you the exact quote if you need it)

this is defined in POSIX.1.
I just reread POSIX.4 and it says that pathconf()/fpathconf() must be
used to collect the information (here, using _PC_PATH_MAX).
If it returns -1 but does not set errno, then there is no limit
for the symbol. Else, PATH_MAX value is returned.
I agree that the default value should not be used directly but queried
instead.

/Fabien