util: Fix MIN_NON_ZERO

MIN_NON_ZERO(1, 0) is evaluated to 0. Rewrite the macro to fix it.

Reported-by: Miroslav Rezanina <mrezanin@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <1468306113-847-1-git-send-email-famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index e63da28..e4c6ae6 100644 (file)
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -151,7 +151,8 @@ extern int daemon(int, int);
 /* Minimum function that returns zero only iff both values are zero.
  * Intended for use with unsigned values only. */
 #ifndef MIN_NON_ZERO
-#define MIN_NON_ZERO(a, b) (((a) != 0 && (a) < (b)) ? (a) : (b))
+#define MIN_NON_ZERO(a, b) ((a) == 0 ? (b) : \
+                                ((b) == 0 ? (a) : (MIN(a, b))))
 #endif
 
 /* Round number down to multiple */