consider TZ-epoch in base-cache (ensure cache of base is correct for :localtime if TZ changing)

2 files changed, 14 insertions, 1 deletions

diff --git a/generic/tclClock.c b/generic/tclClock.c
index e156cf3..1c9f77e 100644
--- a/generic/tclClock.c
+++ b/generic/tclClock.c
@@ -2249,6 +2249,9 @@ ConvertUTCToLocal(
 	    return TCL_ERROR;
 	}
 
+	/* signal we need to revalidate TZ epoch next time fields gets used. */
+	fields->flags |= CLF_CTZ;
+
 	/* we cannot cache (ranges unknown yet) */
     } else {
 	Tcl_WideInt rangesVal[2];
@@ -2258,6 +2261,9 @@ ConvertUTCToLocal(
 	    return TCL_ERROR;
 	}
 
+	/* converted using table (TZ isn't :localtime) */
+	fields->flags &= ~CLF_CTZ;
+
 	/* Cache the last conversion */
 	if (ltzoc != NULL) { /* slot was found above */
 	    /* timezoneObj and changeover are the same */
@@ -3491,7 +3497,10 @@ baseNow:
 
     /* check base fields already cached (by TZ, last-second cache) */
     if ( dataPtr->lastBase.timezoneObj == opts->timezoneObj
-      && dataPtr->lastBase.date.seconds == baseVal) {
+      && dataPtr->lastBase.date.seconds == baseVal
+      && (!(dataPtr->lastBase.date.flags & CLF_CTZ)
+	     || dataPtr->lastTZEpoch == TzsetIfNecessary())
+    ) {
 	memcpy(date, &dataPtr->lastBase.date, ClockCacheableDateFieldsSize);
     } else {
 	/* extact fields from base */
diff --git a/generic/tclDate.h b/generic/tclDate.h
index 6e82a3f..0fd0fef 100644
--- a/generic/tclDate.h
+++ b/generic/tclDate.h
@@ -150,6 +150,8 @@ typedef enum ClockMsgCtLiteral {
 
 typedef enum {BCE=1, CE=0} ERA_ENUM;
 
+#define CLF_CTZ		(1 << 4)
+
 typedef struct TclDateFields {
 
     /* Cacheable fields:	 */
@@ -175,6 +177,8 @@ typedef struct TclDateFields {
     int secondOfMin;		/* Seconds of minute (in-between time only calculation) */
     int secondOfDay;		/* Seconds of day (in-between time only calculation) */
 
+    int flags;			/* 0 or CLF_CTZ */
+
     /* Non cacheable fields:	 */
 
     Tcl_Obj *tzName;		/* Name (or corresponding DST-abbreviation) of the