--- old/src/java.base/share/classes/java/time/zone/ZoneRules.java	2020-02-26 17:19:31.000000000 -0800
+++ new/src/java.base/share/classes/java/time/zone/ZoneRules.java	2020-02-26 17:19:31.000000000 -0800
@@ -470,7 +470,7 @@
      * @return true if the time-zone is fixed and the offset never changes
      */
     public boolean isFixedOffset() {
-        return savingsInstantTransitions.length == 0;
+        return standardTransitions.length == 0 && savingsInstantTransitions.length == 0;
     }
 
     /**
@@ -485,12 +485,13 @@
      * @return the offset, not null
      */
     public ZoneOffset getOffset(Instant instant) {
-        if (savingsInstantTransitions.length == 0) {
+        if (standardTransitions.length == 0 && savingsInstantTransitions.length == 0) {
             return standardOffsets[0];
         }
         long epochSec = instant.getEpochSecond();
         // check if using last rules
         if (lastRules.length > 0 &&
+                savingsInstantTransitions.length > 0 &&
                 epochSec > savingsInstantTransitions[savingsInstantTransitions.length - 1]) {
             int year = findYear(epochSec, wallOffsets[wallOffsets.length - 1]);
             ZoneOffsetTransition[] transArray = findTransitionArray(year);
@@ -640,11 +641,12 @@
     }
 
     private Object getOffsetInfo(LocalDateTime dt) {
-        if (savingsInstantTransitions.length == 0) {
+        if (standardTransitions.length == 0 && savingsInstantTransitions.length == 0) {
             return standardOffsets[0];
         }
         // check if using last rules
         if (lastRules.length > 0 &&
+                savingsInstantTransitions.length > 0 &&
                 dt.isAfter(savingsLocalTransitions[savingsLocalTransitions.length - 1])) {
             ZoneOffsetTransition[] transArray = findTransitionArray(dt.getYear());
             Object info = null;
@@ -756,7 +758,7 @@
      * @return the standard offset, not null
      */
     public ZoneOffset getStandardOffset(Instant instant) {
-        if (savingsInstantTransitions.length == 0) {
+        if (standardTransitions.length == 0 && savingsInstantTransitions.length == 0) {
             return standardOffsets[0];
         }
         long epochSec = instant.getEpochSecond();
@@ -786,7 +788,7 @@
      * @return the difference between the standard and actual offset, not null
      */
     public Duration getDaylightSavings(Instant instant) {
-        if (savingsInstantTransitions.length == 0) {
+        if (standardTransitions.length == 0 && savingsInstantTransitions.length == 0) {
             return Duration.ZERO;
         }
         ZoneOffset standardOffset = getStandardOffset(instant);
--- old/test/jdk/java/time/test/java/time/zone/TestZoneRules.java	2020-02-26 17:19:33.000000000 -0800
+++ new/test/jdk/java/time/test/java/time/zone/TestZoneRules.java	2020-02-26 17:19:32.000000000 -0800
@@ -24,6 +24,7 @@
 package test.java.time.zone;
 
 import java.time.DayOfWeek;
+import java.time.Duration;
 import java.time.Instant;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
@@ -36,6 +37,7 @@
 import java.time.zone.ZoneOffsetTransition;
 import java.time.zone.ZoneOffsetTransitionRule;
 import java.time.zone.ZoneRules;
+import java.util.Arrays;
 import java.util.Collections;
 
 import org.testng.annotations.Test;
@@ -46,7 +48,7 @@
 /**
  * @summary Tests for ZoneRules class.
  *
- * @bug 8212970 8236903
+ * @bug 8212970 8236903 8239836
  */
 @Test
 public class TestZoneRules {
@@ -108,6 +110,15 @@
         };
     }
 
+    @DataProvider
+    private Object[][] emptyTransitionList() {
+        return new Object[][] {
+            // days, offset, std offset, savings, isDST
+            {7, 1, 2, -1, true},
+            {-7, 1, 1, 0, false},
+        };
+    }
+
     /**
      * Test ZoneRules whether the savings are positive in time zones that have
      * negative savings in the source TZ files.
@@ -171,4 +182,27 @@
         ZoneOffset offsetB = zoneRulesB.getOffset(maxLocalDateTime);
         assertEquals(offsetA, offsetB);
     }
+
+    /**
+     * Tests whether empty "transitionList" is correctly interpreted.
+     * @bug 8239836
+     */
+    @Test(dataProvider="emptyTransitionList")
+    public void test_EmptyTransitionList(int days, int offset, int stdOffset, int savings, boolean isDST) {
+        LocalDateTime transitionDay = LocalDateTime.of(2020, 1, 1, 2, 0);
+        Instant testDay = transitionDay.plusDays(days).toInstant(ZoneOffset.UTC);
+        ZoneOffsetTransition trans = ZoneOffsetTransition.of(
+            transitionDay,
+            ZoneOffset.ofHours(1),
+            ZoneOffset.ofHours(2));
+        ZoneRules rules = ZoneRules.of(ZoneOffset.ofHours(1), ZoneOffset.ofHours(1),
+            Arrays.asList(trans),
+            Collections.emptyList(), Collections.emptyList());
+
+        assertEquals(rules.getOffset(testDay), ZoneOffset.ofHours(offset));
+        assertEquals(rules.getStandardOffset(testDay), ZoneOffset.ofHours(stdOffset));
+        assertEquals(rules.getDaylightSavings(testDay), Duration.ofHours(savings));
+        assertEquals(rules.isDaylightSavings(testDay), isDST);
+        assertTrue(!rules.isFixedOffset());
+    }
 }