undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.

test/jdk/java/util/TimeZone/DaylightTimeTest.java

@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2011, 2025, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 6936350 8347841 8347955
+ * @summary Test case for TimeZone.observesDaylightTime()
+ */
+
+import java.time.ZoneId;
+import java.util.*;
+import java.util.function.Predicate;
+import static java.util.GregorianCalendar.*;
+
+public class DaylightTimeTest {
+    private static final int ONE_HOUR = 60 * 60 * 1000; // one hour
+    private static final int INTERVAL = 24 * ONE_HOUR;  // one day
+    private static final String[] ZONES = TimeZone.availableIDs()
+            .filter(Predicate.not(ZoneId.SHORT_IDS::containsKey))
+            .toArray(String[]::new);
+    private static int errors = 0;
+
+    public static void main(String[] args) {
+
+        // Test default TimeZone
+        for (String id : ZONES) {
+            TimeZone tz = TimeZone.getTimeZone(id);
+            long now = System.currentTimeMillis();
+            boolean observes = tz.observesDaylightTime();
+            boolean found = findDSTTransition(tz, now);
+            if (observes != found) {
+                // There's a critical section. If DST ends after the
+                // System.currentTimeMills() call, there should be
+                // inconsistency in the determination. Try the same
+                // thing again to see the inconsistency was due to the
+                // critical section.
+                now = System.currentTimeMillis();
+                observes = tz.observesDaylightTime();
+                found = findDSTTransition(tz, now);
+                if (observes != found) {
+                    System.err.printf("%s: observesDaylightTime() should return %s at %d%n",
+                                      tz.getID(), found, now);
+                    errors++;
+                }
+            }
+        }
+
+        // Test SimpleTimeZone in which observesDaylightTime() is
+        // equivalent to useDaylightTime().
+        testSimpleTimeZone(new SimpleTimeZone(-8*ONE_HOUR, "X",
+                                              APRIL, 1, -SUNDAY, 2*ONE_HOUR,
+                                              OCTOBER, -1, SUNDAY, 2*ONE_HOUR,
+                                              1*ONE_HOUR));
+        testSimpleTimeZone(new SimpleTimeZone(-8*ONE_HOUR, "Y"));
+
+        if (errors > 0) {
+            throw new RuntimeException("DaylightTimeTest: failed");
+        }
+    }
+
+    /**
+     * Returns true if it's `now' in DST or there's any
+     * standard-to-daylight transition within 50 years after `now'.
+     */
+    private static boolean findDSTTransition(TimeZone tz, long now) {
+        GregorianCalendar cal = new GregorianCalendar(tz, Locale.US);
+        cal.setTimeInMillis(now);
+        cal.add(YEAR, 50);
+        long end = cal.getTimeInMillis();
+
+        for (long t = now; t < end; t += INTERVAL) {
+            cal.setTimeInMillis(t);
+            if (cal.get(DST_OFFSET) > 0) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private static void testSimpleTimeZone(SimpleTimeZone stz) {
+        if (stz.useDaylightTime() != stz.observesDaylightTime()) {
+            System.err.printf("Failed: useDaylightTime=%b, observesDaylightTime()=%b%n\t%s%n",
+                              stz.useDaylightTime(),stz.observesDaylightTime(), stz);
+            errors++;
+        }
+    }
+}