merge revision(s) 011d4c57d21220249600dfb76db84840550da019: [Backport #19106]

	[Bug #19106] Normalize time at 24:00:00 with a timezone object

	---
	 test/ruby/test_time_tz.rb |  5 +++++
	 time.c                    | 24 ++++++++++++++++--------
	 2 files changed, 21 insertions(+), 8 deletions(-)

3 files changed, 22 insertions, 9 deletions

diff --git a/test/ruby/test_time_tz.rb b/test/ruby/test_time_tz.rb
index fdc9e114b5..b6785f3360 100644
--- a/test/ruby/test_time_tz.rb
+++ b/test/ruby/test_time_tz.rb
@@ -612,6 +612,11 @@ module TestTimeTZ::WithTZ
     assert_raise(ArgumentError) {time_class.new(2018, 9, 1, 12, 0, 0, tzarg, in: tzarg)}
   end
 
+  def subtest_hour24(time_class, tz, tzarg, tzname, abbr, utc_offset)
+    t = time_class.new(2000, 1, 1, 24, 0, 0, tzarg)
+    assert_equal([0, 0, 0, 2, 1, 2000], [t.sec, t.min, t.hour, t.mday, t.mon, t.year])
+  end
+
   def subtest_now(time_class, tz, tzarg, tzname, abbr, utc_offset)
     t = time_class.now(in: tzarg)
     assert_equal(tz, t.zone)
diff --git a/time.c b/time.c
index 992e5403d0..a136dcbe8e 100644
--- a/time.c
+++ b/time.c
@@ -2324,6 +2324,19 @@ find_timezone(VALUE time, VALUE zone)
     return rb_check_funcall_default(klass, id_find_timezone, 1, &zone, Qnil);
 }
 
+/* Turn the special case 24:00:00 of already validated vtm into
+ * 00:00:00 the next day */
+static void
+vtm_day_wraparound(struct vtm *vtm)
+{
+    if (vtm->hour < 24) return;
+
+    /* Assuming UTC and no care of DST, just reset hour and advance
+     * date, not to discard the validated vtm. */
+    vtm->hour = 0;
+    vtm_add_day(vtm, 1);
+}
+
 static VALUE
 time_init_args(rb_execution_context_t *ec, VALUE time, VALUE year, VALUE mon, VALUE mday, VALUE hour, VALUE min, VALUE sec, VALUE zone)
 {
@@ -2379,6 +2392,7 @@ time_init_args(rb_execution_context_t *ec, VALUE time, VALUE year, VALUE mon, VA
 
     if (!NIL_P(zone)) {
         tobj->timew = timegmw(&vtm);
+        vtm_day_wraparound(&vtm);
         tobj->vtm = vtm;
         tobj->tm_got = 1;
         TZMODE_SET_LOCALTIME(tobj);
@@ -2393,13 +2407,7 @@ time_init_args(rb_execution_context_t *ec, VALUE time, VALUE year, VALUE mon, VA
 
     if (utc == UTC_ZONE) {
         tobj->timew = timegmw(&vtm);
-        if (vtm.hour == 24) { /* special case: 24:00:00 only */
-            /* Since no need to take care of DST in UTC, just reset
-             * hour and advance date, not to discard the validated
-             * vtm. */
-            vtm.hour = 0;
-            vtm_add_day(&vtm, 1);
-        }
+        vtm_day_wraparound(&vtm);
         tobj->vtm = vtm;
         tobj->tm_got = 1;
         TZMODE_SET_UTC(tobj);
@@ -4054,7 +4062,7 @@ time_inspect(VALUE time)
     GetTimeval(time, tobj);
     str = strftimev("%Y-%m-%d %H:%M:%S", time, rb_usascii_encoding());
     subsec = w2v(wmod(tobj->timew, WINT2FIXWV(TIME_SCALE)));
-    if (FIXNUM_P(subsec) && FIX2LONG(subsec) == 0) {
+    if (subsec == INT2FIX(0)) {
     }
     else if (FIXNUM_P(subsec) && FIX2LONG(subsec) < TIME_SCALE) {
         long len;
diff --git a/version.h b/version.h
index 985014e52f..6a2e2abcf9 100644
--- a/version.h
+++ b/version.h
@@ -11,7 +11,7 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 3
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 179
+#define RUBY_PATCHLEVEL 180
 
 #define RUBY_RELEASE_YEAR 2022
 #define RUBY_RELEASE_MONTH 11