Modified for downstream inclusion in tzdata-java.

commit 1bc13a1c10a580f84f1b7686c95344ec2633f611
Author: Florian Weimer <fweimer@openjdk.org>
Date:   Thu Sep 26 22:37:45 2024 +0000

    8340552: Harden TzdbZoneRulesCompiler against missing zone names

    Reviewed-by: andrew, jlu, naoto

diff -ur tzdata-2024b.orig/javazic-1.8/build/tools/tzdb/TzdbZoneRulesCompiler.java tzdata-2024b/javazic-1.8/build/tools/tzdb/TzdbZoneRulesCompiler.java
--- tzdata-2024b.orig/javazic-1.8/build/tools/tzdb/TzdbZoneRulesCompiler.java	2014-04-22 19:46:49.000000000 +0200
+++ tzdata-2024b/javazic-1.8/build/tools/tzdb/TzdbZoneRulesCompiler.java	2024-09-20 21:10:12.748483767 +0200
@@ -248,7 +248,7 @@
             // link version-region-rules
             out.writeShort(builtZones.size());
             for (Map.Entry<String, ZoneRules> entry : builtZones.entrySet()) {
-                 int regionIndex = Arrays.binarySearch(regionArray, entry.getKey());
+                 int regionIndex = findRegionIndex(regionArray, entry.getKey());
                  int rulesIndex = rulesList.indexOf(entry.getValue());
                  out.writeShort(regionIndex);
                  out.writeShort(rulesIndex);
@@ -256,8 +256,8 @@
             // alias-region
             out.writeShort(links.size());
             for (Map.Entry<String, String> entry : links.entrySet()) {
-                 int aliasIndex = Arrays.binarySearch(regionArray, entry.getKey());
-                 int regionIndex = Arrays.binarySearch(regionArray, entry.getValue());
+                 int aliasIndex = findRegionIndex(regionArray, entry.getKey());
+                 int regionIndex = findRegionIndex(regionArray, entry.getValue());
                  out.writeShort(aliasIndex);
                  out.writeShort(regionIndex);
             }
@@ -269,6 +269,14 @@
         }
     }
 
+    private static int findRegionIndex(String[] regionArray, String region) {
+        int index = Arrays.binarySearch(regionArray, region);
+        if (index < 0) {
+            throw new IllegalArgumentException("Unknown region: " + region);
+        }
+        return index;
+    }
+
     private static final Pattern YEAR = Pattern.compile("(?i)(?<min>min)|(?<max>max)|(?<only>only)|(?<year>[0-9]+)");
     private static final Pattern MONTH = Pattern.compile("(?i)(jan)|(feb)|(mar)|(apr)|(may)|(jun)|(jul)|(aug)|(sep)|(oct)|(nov)|(dec)");
     private static final Matcher DOW = Pattern.compile("(?i)(mon)|(tue)|(wed)|(thu)|(fri)|(sat)|(sun)").matcher("");
@@ -607,22 +615,20 @@
             }
             builtZones.put(aliasId, realRules);
         }
-        // remove UTC and GMT
-        // builtZones.remove("UTC");
-        // builtZones.remove("GMT");
-        // builtZones.remove("GMT0");
-        builtZones.remove("GMT+0");
-        builtZones.remove("GMT-0");
-        links.remove("GMT+0");
-        links.remove("GMT-0");
-        // remove ROC, which is not supported in j.u.tz
-        builtZones.remove("ROC");
-        links.remove("ROC");
-        // remove EST, HST and MST. They are supported via
-        // the short-id mapping
-        builtZones.remove("EST");
-        builtZones.remove("HST");
-        builtZones.remove("MST");
+
+        List<String> zonesToRemove = Arrays.asList(
+            // remove UTC and GMT
+            "GMT+0",
+            "GMT-0",
+            // remove ROC, which is not supported in j.u.tz
+            "ROC",
+            // remove EST, HST and MST. They are supported via
+            // the short-id mapping
+            "EST",
+            "HST",
+            "MST");
+        builtZones.keySet().removeAll(zonesToRemove);
+        links.keySet().removeAll(zonesToRemove);
     }
 
     /**