1 files changed, 9 insertions, 6 deletions
diff --git a/src/libstddjb/tain_add.c b/src/libstddjb/tain_add.c
index 6c6a237..aa6e705 100644
--- a/src/libstddjb/tain_add.c
+++ b/src/libstddjb/tain_add.c
@@ -2,13 +2,16 @@
 
 #include <skalibs/tai.h>
 
-void tain_add (tain_t *t, tain_t const *u, tain_t const *v)
+int tain_add (tain_t *t, tain_t const *u, tain_t const *v)
 {
-  tai_add(&t->sec, &u->sec, &v->sec) ;
-  t->nano = u->nano + v->nano ;
-  if (t->nano > 999999999U)
+  tain_t tt = *u ;
+  if (!tai_add(&tt.sec, &u->sec, &v->sec)) return 0 ;
+  tt.nano = u->nano + v->nano ;
+  if (tt.nano > 999999999U)
   {
-    t->nano -= 1000000000U ;
-    tai_u64(&t->sec, tai_sec(&t->sec)+1) ;
+    if (!tai_u64(&tt.sec, tai_sec(&tt.sec) + 1)) return 0 ;
+    tt.nano -= 1000000000U ;
   }
+  *t = tt ;
+  return 1 ;
 }