clock:_TOD_To_seconds(): Fix year 2514 overflow

This patch fixes issue #4338 by changing _TOD_Validate()
to only accept years till 2105. This requires another patch
to change the documentation of rtems_clock_set() and other
affected API functions (indicating the end date is 2105 not 2514).

I tried to support till year 2514 but it turned out that
this needs changing the Timer Manager too. That in turn
would mean to change _TOD_Seconds_since_epoch( void )
from 32 to 64 bit. Sebastian pointed out that a naive extension
leads to trouble with 32 bit processors. He deemed a safe
re-implementation too costly performance wise considering
that year 2106 is far away and current binaries using RTEMS
Classic API are unlikely to be in use by 2106.

The constant TOD_SECONDS_AT_2100_03_01_00_00 in
cpukit/rtems/src/clocktodtoseconds.c happens to be wrong by
1 hour. When setting the date 2100-Feb-28 23:59:59 and then
reading the date again you will find yourself in 2100-Feb-27.

Update #4338

1 files changed, 18 insertions, 10 deletions

diff --git a/testsuites/sptests/sp2038/init.c b/testsuites/sptests/sp2038/init.c
index a3f09d4156..10850d9c4d 100644
--- a/testsuites/sptests/sp2038/init.c
+++ b/testsuites/sptests/sp2038/init.c
@@ -149,8 +149,7 @@ static const uint32_t sample_seconds [] = {
   4168736895UL,
   4200272895UL,
   4231808895UL,
-  4263431295UL,
-  4294967295UL
+  4263431295UL
 };
 
 static const rtems_time_of_day nearly_problem_2038 = {
@@ -171,8 +170,8 @@ static const rtems_time_of_day problem_2038 = {
   .second = 8
 };
 
-static const rtems_time_of_day nearly_problem_2106 = {
-  .year = 2106,
+static const rtems_time_of_day tod_to_seconds_base = {
+  .year = 0,
   .month = 2,
   .day = 7,
   .hour = 6,
@@ -180,13 +179,22 @@ static const rtems_time_of_day nearly_problem_2106 = {
   .second = 15
 };
 
+static const rtems_time_of_day nearly_problem_2106 = {
+  .year = 2105,
+  .month = 12,
+  .day = 31,
+  .hour = 23,
+  .minute = 59,
+  .second = 59
+};
+
 static const rtems_time_of_day problem_2106 = {
   .year = 2106,
-  .month = 2,
-  .day = 7,
-  .hour = 6,
-  .minute = 28,
-  .second = 16
+  .month = 1,
+  .day = 1,
+  .hour = 0,
+  .minute = 0,
+  .second = 0
 };
 
 static const rtems_time_of_day problem_2100 = {
@@ -214,7 +222,7 @@ static void test_tod_to_seconds(void)
   size_t n = sizeof(sample_seconds) / sizeof(sample_seconds [0]);
 
   for (i = 0; i < n; ++i) {
-    rtems_time_of_day tod = nearly_problem_2106;
+    rtems_time_of_day tod = tod_to_seconds_base;
     uint32_t seconds = 0;
     rtems_interval seconds_as_interval = 0;