---
zic.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/zic.c b/zic.c
index cf449a55..70a2ab09 100644
--- a/zic.c
+++ b/zic.c
@@ -2666,7 +2666,7 @@ writezone(const char *const name, const char *const
string, char version,
if (timecnt > 1)
qsort(attypes, timecnt, sizeof *attypes, atcomp);
/*
- ** Optimize.
+ ** Optimize and skip unwanted transitions.
*/
{
ptrdiff_t fromi, toi;
@@ -2675,6 +2675,10 @@ writezone(const char *const name, const char *const
string, char version,
fromi = 0;
for ( ; fromi < timecnt; ++fromi) {
if (toi != 0) {
+ /* Skip the previous transition if it is unwanted
+ because its local time is not earlier.
+ The UT offset additions can't overflow because
+ of how the times were calculated. */
unsigned char type_2 =
toi == 1 ? 0 : attypes[toi - 2].type;
if ((attypes[fromi].at
@@ -2688,6 +2692,10 @@ writezone(const char *const name, const char *const
string, char version,
continue;
}
}
+
+ /* Use a transition if it is the first one,
+ or if it cannot be merged for other reasons,
+ or if it transitions to different timekeeping. */
if (toi == 0
|| attypes[fromi].dontmerge
|| (utoffs[attypes[toi - 1].type]
--
2.51.0
