? st_blocks ((statbuf).st_size) : 0)
# endif /* !_POSIX_SOURCE && BSIZE */
#else /* HAVE_STRUCT_STAT_ST_BLOCKS */
-/* Some systems, like Sequents, return st_blksize of 0 on pipes. */
-# define ST_BLKSIZE(statbuf) ((statbuf).st_blksize > 0 \
- ? (statbuf).st_blksize : DEV_BSIZE)
+/* Some systems, like Sequents, return st_blksize of 0 on pipes.
+ Also, when running `cat large-file | rsh hp-ux-system', cat would
+ determine that the output stream had an st_blksize of 2147421096.
+ So here we arbitrarily limit the `optimal' block size to 4MB.
+ If anyone knows of a system for which the legitimate value for
+ st_blksize can exceed 4MB, please report it as a bug in this code. */
+# define ST_BLKSIZE(statbuf) ((0 < (statbuf).st_blksize \
+ && (statbuf).st_blksize <= (1 << 22)) /* 4MB */ \
+ ? (statbuf).st_blksize : DEV_BSIZE)
# if defined hpux || defined __hpux__ || defined __hpux
/* HP-UX counts st_blocks in 1024-byte units.
This loses when mixing HP-UX and BSD filesystems with NFS. */