diff 2.8 large file read fails for Tru64 5.1

[Mike Coleman]

Under Tru64 5.1 (gcc 3.0.3), it looks like read(2) won't accept a size
argument greater than 2^31-1 (although the man page implies that this
should work).  I see the same error using the vendor's 'cc'.

Perhaps diff could use smaller reads in this case or (ugh) retry on an
initial read failure.

Regards,
Mike


partial truss output from a diff run:

open("db/nt", O_RDONLY, 00)                     = 6
open("dbold/nt", O_RDONLY, 00)                  = 7
read(6, " > g i | 1 6 8 2 5 7 | g".., 8192)     = 8192
brk(0x0000000140020DC0)                         = 0
read(7, " > g i | 4 0 0 3 3 6 8 |".., 8192)     = 8192
brk(0x000000027CA98DC0)                         = 0
read(6, 0x0000000140015000, 5312561138)         Err#22 Invalid argument