Remove the --enable-right-tz configure option.

 Make it a run-time autodetection instead.
 Update doc.
 Thanks to Paul Jarc for the suggestion.

6 files changed, 43 insertions, 44 deletions

diff --git a/src/include/skalibs/djbtime.h b/src/include/skalibs/djbtime.h
index 8aace55..7e60cd4 100644
--- a/src/include/skalibs/djbtime.h
+++ b/src/include/skalibs/djbtime.h
@@ -27,7 +27,7 @@ extern int tain_from_ntp (tain_t *, uint64) ;
 
 
 /* localtime handling - replaces caltimedate functions */
-/* ltm64 can be either TAI-10 or UTC depending on --enable-right-tz */
+/* ltm64 can be either TAI-10 or UTC depending on the current timezone */
 /* normally ltm64 is the same as sysclock, but we allow it to be different */
 /* for instance for musl TAI-10 systems */
 
diff --git a/src/libstddjb/djbtime-internal.h b/src/libstddjb/djbtime-internal.h
index 26ffc81..819b88a 100644
--- a/src/libstddjb/djbtime-internal.h
+++ b/src/libstddjb/djbtime-internal.h
@@ -6,7 +6,7 @@
 #include <skalibs/uint64.h>
 
 
-/* Leap second handling, for UTC <--> TAI conversions */
+ /* Leap second handling, for UTC <--> TAI conversions */
 
 #define LEAPSECS_MAX 39
 #define LEAPSECS_FILE SKALIBS_ETC "/leapsecs.dat"
@@ -20,4 +20,8 @@ extern int leapsecs_sub_r (uint64 *, char const *, uint64 *) ;
 #define leapsecs_sub(t) leapsecs_sub_r((t), LEAPSECS_FILE, leapsecs_here)
 
 
+ /* Run-time test: does the current timezone handle leap seconds ? */
+
+extern int skalibs_tzisright (void) ;
+
 #endif
diff --git a/src/libstddjb/ltm64_from_tai.c b/src/libstddjb/ltm64_from_tai.c
index c0650c5..9161a79 100644
--- a/src/libstddjb/ltm64_from_tai.c
+++ b/src/libstddjb/ltm64_from_tai.c
@@ -1,23 +1,16 @@
 /* ISC license. */
 
-#include <skalibs/config.h>
 #include <skalibs/uint64.h>
 #include <skalibs/tai.h>
 #include <skalibs/djbtime.h>
-
-#ifdef SKALIBS_FLAG_TZISRIGHT
+#include "djbtime-internal.h"
 
 int ltm64_from_tai (uint64 *u, tai_t const *t)
 {
-  *u = t->x - 10U ;
-  return 1 ;
+  switch (skalibs_tzisright())
+  {
+    case 1 : *u = t->x - 10U ; return 1 ;
+    case 0 : return utc_from_tai(u, t) ;
+    default : return 0 ;
+  }
 }
-
-#else
-
-int ltm64_from_tai (uint64 *u, tai_t const *t)
-{
-  return utc_from_tai(u, t) ;
-}
-
-#endif
diff --git a/src/libstddjb/ltm64_from_utc.c b/src/libstddjb/ltm64_from_utc.c
index 8d66813..28907c9 100644
--- a/src/libstddjb/ltm64_from_utc.c
+++ b/src/libstddjb/ltm64_from_utc.c
@@ -1,23 +1,15 @@
 /* ISC license. */
 
-#include <skalibs/config.h>
 #include <skalibs/uint64.h>
 #include <skalibs/djbtime.h>
 #include "djbtime-internal.h"
 
-#ifdef SKALIBS_FLAG_TZISRIGHT
-
 int ltm64_from_utc (uint64 *u)
 {
-  return (leapsecs_add(u, 0) >= 0) ;
+  switch (skalibs_tzisright())
+  {
+    case 1 : return leapsecs_add(u, 0) >= 0 ;
+    case 0 : return 1 ;
+    default : return 0 ;
+  }
 }
-
-#else
-
-int ltm64_from_utc (uint64 *u)
-{
-  (void)u ;
-  return 1 ;
-}
-
-#endif
diff --git a/src/libstddjb/skalibs_tzisright.c b/src/libstddjb/skalibs_tzisright.c
new file mode 100644
index 0000000..f8414a6
--- /dev/null
+++ b/src/libstddjb/skalibs_tzisright.c
@@ -0,0 +1,17 @@
+/* ISC license. */
+
+#include <sys/types.h>
+#include <time.h>
+#include "djbtime-internal.h"
+
+int skalibs_tzisright ()
+{
+  static int tzisright = -1 ;
+  if (tzisright < 0)
+  {
+    struct tm tm ;
+    time_t t = 78796800 ;
+    if (localtime_r(&t, &tm)) tzisright = tm.tm_sec == 60 ;
+  }
+  return tzisright ;
+}
diff --git a/src/libstddjb/tai_from_ltm64.c b/src/libstddjb/tai_from_ltm64.c
index 2538c00..12a7394 100644
--- a/src/libstddjb/tai_from_ltm64.c
+++ b/src/libstddjb/tai_from_ltm64.c
@@ -1,23 +1,16 @@
 /* ISC license. */
 
-#include <skalibs/config.h>
 #include <skalibs/uint64.h>
 #include <skalibs/tai.h>
 #include <skalibs/djbtime.h>
-
-#ifdef SKALIBS_FLAG_TZISRIGHT
+#include "djbtime-internal.h"
 
 int tai_from_ltm64 (tai_t *t, uint64 u)
 {
-  tai_u64(t, u + 10U) ;
-  return 1 ;
+  switch (skalibs_tzisright())
+  {
+    case 1 : tai_u64(t, u + 10U) ; return 1 ;
+    case 0 : return tai_from_utc(t, u) ;
+    default : return 0 ;
+  }
 }
-
-#else
-
-int tai_from_ltm64 (tai_t *t, uint64 u)
-{
-  return tai_from_utc(t, u) ;
-}
-
-#endif