Comment possible numeric overflow in timespec_diff_ns()

timespec_diff_ns() should not be used is the delta is more than
about 2 seconds.

1 files changed, 1 insertions, 0 deletions

diff --git a/gps.h b/gps.h
index 6bf7c336..20a5f5e8 100644
--- a/gps.h
+++ b/gps.h
@@ -1891,6 +1891,7 @@ struct timedrift_t {
 
 /* difference between timespecs in nanoseconds */
 /* int is too small, avoid floats  */
+/* WARNING!  this will overflow if x and y differ by more than a few seconds */
 #define timespec_diff_ns(x, y)	(long)(((x).tv_sec-(y).tv_sec)*1000000000+(x).tv_nsec-(y).tv_nsec)
 
 /*