1 files changed, 77 insertions, 2 deletions

diff --git a/sumtimespec.c b/sumtimespec.c
index c4bf68c..a359971 100644
--- a/sumtimespec.c
+++ b/sumtimespec.c
@@ -1,9 +1,10 @@
 /* See LICENSE file for copyright and license details. */
 #include "libsimple.h"
+#ifndef TEST
 
 
 int
-libsimple_sumtimespec(struct timespec *sum, const struct timespec *augend, const struct timespec *addend) /* TODO test */
+libsimple_sumtimespec(struct timespec *sum, const struct timespec *augend, const struct timespec *addend)
 {
 	long int ns = augend->tv_nsec + addend->tv_nsec;
 	time_t s;
@@ -16,7 +17,7 @@ libsimple_sumtimespec(struct timespec *sum, const struct timespec *augend, const
 			ns = 999999999L;
 			errno = ERANGE;
 			ret = -1;
-		} else if (augend->tv_sec < 0 && augend->tv_sec + addend->tv_sec < TIME_MIN) {
+		} else if (augend->tv_sec < 0 && augend->tv_sec < TIME_MIN - addend->tv_sec) {
 			s = TIME_MIN;
 			ns = 0;
 			errno = ERANGE;
@@ -48,3 +49,77 @@ libsimple_sumtimespec(struct timespec *sum, const struct timespec *augend, const
 	sum->tv_nsec = ns;
 	return ret;
 }
+
+
+#else
+#include "test.h"
+
+int
+main(void)
+{
+	struct timespec r, a, b;
+
+	a.tv_sec = 0, a.tv_nsec = 0;
+	b.tv_sec = 0, b.tv_nsec = 0;
+	assert(!libsimple_sumtimespec(&r, &a, &b));
+	assert(r.tv_sec  == 0);
+	assert(r.tv_nsec == 0);
+
+	a.tv_sec = 10, a.tv_nsec = 10000L;
+	b.tv_sec =  0, b.tv_nsec =     0L;
+	assert(!libsimple_sumtimespec(&r, &a, &b));
+	assert(r.tv_sec  == 10);
+	assert(r.tv_nsec == 10000L);
+
+	a.tv_sec =  10, a.tv_nsec = 10000L;
+	b.tv_sec = -10, b.tv_nsec =     0L;
+	assert(!libsimple_sumtimespec(&r, &a, &b));
+	assert(r.tv_sec  == 0);
+	assert(r.tv_nsec == 10000L);
+
+	a.tv_sec =  10, a.tv_nsec = 10000L;
+	b.tv_sec = -20, b.tv_nsec = 20000L;
+	assert(!libsimple_sumtimespec(&r, &a, &b));
+	assert(r.tv_sec  == -10);
+	assert(r.tv_nsec == 30000L);
+
+	a.tv_sec = 1, a.tv_nsec = 999999999L;
+	b.tv_sec = 1, b.tv_nsec =         1L;
+	assert(!libsimple_sumtimespec(&r, &a, &b));
+	assert(r.tv_sec  == 3);
+	assert(r.tv_nsec == 0L);
+
+	a.tv_sec = TIME_MAX, a.tv_nsec = 0L;
+	b.tv_sec = TIME_MAX, b.tv_nsec = 0L;
+	assert(libsimple_sumtimespec(&r, &a, &b) == -1);
+	assert(r.tv_sec  == TIME_MAX);
+	assert(r.tv_nsec == 999999999L);
+
+	a.tv_sec = TIME_MAX, a.tv_nsec = 999999999L;
+	b.tv_sec =        0, b.tv_nsec =         1L;
+	assert(libsimple_sumtimespec(&r, &a, &b) == -1);
+	assert(r.tv_sec  == TIME_MAX);
+	assert(r.tv_nsec == 999999999L);
+
+	a.tv_sec = TIME_MAX, a.tv_nsec =         1L;
+	b.tv_sec =        0, b.tv_nsec = 999999999L;
+	assert(libsimple_sumtimespec(&r, &a, &b) == -1);
+	assert(r.tv_sec  == TIME_MAX);
+	assert(r.tv_nsec == 999999999L);
+
+	a.tv_sec = TIME_MIN, a.tv_nsec = 0L;
+	b.tv_sec = TIME_MIN, b.tv_nsec = 0L;
+	assert(libsimple_sumtimespec(&r, &a, &b) == -1);
+	assert(r.tv_sec  == TIME_MIN);
+	assert(r.tv_nsec == 0L);
+
+	a.tv_sec = TIME_MIN, a.tv_nsec = 100L;
+	b.tv_sec = TIME_MIN, b.tv_nsec = 100L;
+	assert(libsimple_sumtimespec(&r, &a, &b) == -1);
+	assert(r.tv_sec  == TIME_MIN);
+	assert(r.tv_nsec == 0L);
+
+	return 0;
+}
+
+#endif