Retryable with exponential backoff not working with delayExpression

src/main/java/org/springframework/retry/backoff/ExponentialBackOffPolicy.java

@@ -259,7 +259,7 @@ static class ExponentialBackOffContext implements BackOffContext {
 
 		private final long maxInterval;
 
-		private Supplier<Long> intervalSupplier;
+		private final Supplier<Long> initialIntervalSupplier;
 
 		private Supplier<Double> multiplierSupplier;
 
@@ -271,7 +271,7 @@ public ExponentialBackOffContext(long interval, double multiplier, long maxInter
 			this.interval = interval;
 			this.multiplier = multiplier;
 			this.maxInterval = maxInterval;
-			this.intervalSupplier = intervalSupplier;
+			this.initialIntervalSupplier = intervalSupplier;
 			this.multiplierSupplier = multiplierSupplier;
 			this.maxIntervalSupplier = maxIntervalSupplier;
 		}
@@ -289,15 +289,27 @@ public synchronized long getSleepAndIncrement() {
 		}
 
 		protected long getNextInterval() {
-			return (long) (this.interval * getMultiplier());
+			if (initialIntervalSupplier == null) {
+				return (long) (this.interval * getMultiplier());
+			}
+			else {
+				return this.interval == DEFAULT_INITIAL_INTERVAL
+						? (long) (this.initialIntervalSupplier.get() * getMultiplier())
+						: (long) (this.interval * getMultiplier());
+			}
 		}
 
 		public double getMultiplier() {
 			return this.multiplierSupplier != null ? this.multiplierSupplier.get() : this.multiplier;
 		}
 
 		public long getInterval() {
-			return this.intervalSupplier != null ? this.intervalSupplier.get() : this.interval;
+			if (initialIntervalSupplier == null) {
+				return this.interval;
+			}
+			else {
+				return this.interval == DEFAULT_INITIAL_INTERVAL ? this.initialIntervalSupplier.get() : this.interval;
+			}
 		}
 
 		public long getMaxInterval() {

src/test/java/org/springframework/retry/backoff/ExponentialBackOffPolicyTests.java

@@ -94,6 +94,22 @@ public void testMultiBackOff() {
 		}
 	}
 
+	@Test
+	public void testMultiBackOffWithInitialDelaySupplier() {
+		ExponentialBackOffPolicy strategy = new ExponentialBackOffPolicy();
+		long seed = 40;
+		double multiplier = 1.2;
+		strategy.initialIntervalSupplier(() -> 40L);
+		strategy.setMultiplier(multiplier);
+		strategy.setSleeper(sleeper);
+		BackOffContext context = strategy.start(null);
+		for (int x = 0; x < 5; x++) {
+			strategy.backOff(context);
+			assertThat(sleeper.getLastBackOff()).isEqualTo(seed);
+			seed *= multiplier;
+		}
+	}
+
 	@Test
 	public void testInterruptedStatusIsRestored() {
 		ExponentialBackOffPolicy strategy = new ExponentialBackOffPolicy();