timezone: for kickstart allow also timezones not offered by GUI

Resolves: RHEL-13151

For example Japan, which is linked to Asia/Tokyo in Olson tz database,
and we offer only Asia/Tokyo in GUI.

pyanaconda/modules/timezone/installation.py

@@ -24,7 +24,7 @@
 from pyanaconda.anaconda_loggers import get_module_logger
 from pyanaconda.modules.common.errors.installation import TimezoneConfigurationError
 from pyanaconda.modules.common.task import Task
-from pyanaconda.timezone import is_valid_timezone
+from pyanaconda.timezone import is_valid_timezone, is_valid_ui_timezone
 
 from blivet import arch
 
@@ -60,7 +60,11 @@ def run(self):
 
     def _correct_timezone(self):
         """Ensure the timezone is valid."""
-        if not is_valid_timezone(self._timezone):
+        if is_valid_timezone(self._timezone):
+            if not is_valid_ui_timezone(self._timezone):
+                log.warning("Timezone specification %s set in kickstart is "
+                            "not offered by installer GUI.", self._timezone)
+        else:
             # this should never happen, but for pity's sake
             log.warning("Timezone %s set in kickstart is not valid, "
                         "falling back to default (America/New_York).", self._timezone)

pyanaconda/timezone.py

@@ -148,9 +148,9 @@ def get_all_regions_and_timezones():
     return result
 
 
-def is_valid_timezone(timezone):
+def is_valid_ui_timezone(timezone):
     """
-    Check if a given string is an existing timezone.
+    Check if a given string is a timezone specification offered by GUI.
 
     :type timezone: str
     :rtype: bool
@@ -162,6 +162,23 @@ def is_valid_timezone(timezone):
     return timezone in pytz.common_timezones + etc_zones
 
 
+def is_valid_timezone(timezone):
+    """
+    Check if a given string is a valid timezone specification.
+
+    This includes also deprecated/backward timezones linked to other timezones
+    in tz database (eg Japan -> Asia/Tokyo). Both the tzdata package (installed
+    system) and TimezoneMap widget (installer GUI) should support them and be
+    able link them to the correct timezone specification using the data from
+    "backward" file.
+
+    :type timezone: str
+    :rtype: bool
+    """
+
+    return is_valid_ui_timezone(timezone) or timezone in pytz.all_timezones
+
+
 def get_timezone(timezone):
     """
     Return a tzinfo object for a given timezone name.

pyanaconda/ui/gui/spokes/datetime_spoke.py

@@ -48,7 +48,8 @@
 from pyanaconda.threading import threadMgr, AnacondaThread
 from pyanaconda.core.i18n import _, CN_
 from pyanaconda.core.async_utils import async_action_wait, async_action_nowait
-from pyanaconda.timezone import NTP_SERVICE, get_all_regions_and_timezones, get_timezone, is_valid_timezone
+from pyanaconda.timezone import NTP_SERVICE, get_all_regions_and_timezones, get_timezone, \
+    is_valid_timezone, is_valid_ui_timezone
 from pyanaconda.localization import get_xlated_timezone, resolve_date_format
 from pyanaconda.core.timer import Timer
 
@@ -557,8 +558,14 @@ def _initialize(self):
 
         self._update_datetime_timer = None
         kickstart_timezone = self._timezone_module.Timezone
-        if is_valid_timezone(kickstart_timezone):
+        if is_valid_ui_timezone(kickstart_timezone):
             self._set_timezone(kickstart_timezone)
+        elif is_valid_timezone(kickstart_timezone):
+            log.warning("Timezone specification %s is not offered by installer GUI.",
+                        kickstart_timezone)
+            # Try to get the correct linked timezone via TimezoneMap selection
+            self._tzmap.set_timezone(kickstart_timezone)
+
         elif not flags.flags.automatedInstall:
             log.warning("%s is not a valid timezone, falling back to default (%s)",
                         kickstart_timezone, DEFAULT_TZ)