test-genzeros: avoid raw write(2)

This test helper feeds 256kB of data at once to a single invocation
of the write(2) system call, which may be too much for some
platforms.

Call our xwrite() wrapper that knows to honor MAX_IO_SIZE limit and
cope with short writes due to EINTR instead, and die a bit more
loudly by calling die_errno() when xwrite() indicates an error.

Reported-by: Randall S. Becker <rsbecker@nexbridge.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/helper/test-genzeros.c b/t/helper/test-genzeros.c
index 8ca988d6216e7895d8afea772e110b7eeaa875d1..47af843b6816005f2370fb130bc9f2bde873c029 100644 (file)
--- a/t/helper/test-genzeros.c
+++ b/t/helper/test-genzeros.c
@@ -17,15 +17,16 @@ int cmd__genzeros(int argc, const char **argv)
 
        /* Writing out individual NUL bytes is slow... */
        while (count < 0)
-               if (write(1, zeros, ARRAY_SIZE(zeros)) < 0)
-                       return -1;
+               if (xwrite(1, zeros, ARRAY_SIZE(zeros)) < 0)
+                       die_errno("write error");
 
        while (count > 0) {
-               n = write(1, zeros, count < ARRAY_SIZE(zeros) ?
-                         count : ARRAY_SIZE(zeros));
+               n = xwrite(1, zeros,
+                          count < ARRAY_SIZE(zeros)
+                          ? count : ARRAY_SIZE(zeros));
 
                if (n < 0)
-                       return -1;
+                       die_errno("write error");
 
                count -= n;
        }