HHH-10219 - Infinite loop generating IDs if using negative increment

(cherry picked from commit cd7212a)

Author: sebersole

hibernate-core/src/main/java/org/hibernate/id/enhanced/NoopOptimizer.java

@@ -37,10 +37,13 @@ public Serializable generate(AccessCallback callback) {
 		// reliable as it might be mutated by multipled threads.
 		// The lastSourceValue field is only accessed by tests,
 		// so this is not a concern.
-		IntegralDataTypeHolder value = null;
-		while ( value == null || value.lt( 1 ) ) {
-			value = callback.getNextValue();
+		IntegralDataTypeHolder value = callback.getNextValue();
+		if ( incrementSize > 0 ) {
+			while ( value.lt( 1 ) ) {
+				value = callback.getNextValue();
+			}
 		}
+
 		lastSourceValue = value;
 		return value.makeValue();
 	}

hibernate-core/src/test/java/org/hibernate/id/enhanced/OptimizerUnitTest.java

@@ -42,6 +42,28 @@ public void testBasicNoOptimizerUsage() {
 		assertEquals( 11, sequence.getTimesCalled() ); // an extra time to get to 1 initially
 		assertEquals( 10, sequence.getCurrentValue() );
 	}
+	@Test
+	public void testBasicNoOptimizerUsageWithNegativeValues() {
+		// test historic sequence behavior, where the initial values start at 1...
+		SourceMock sequence = new SourceMock( -1, -1 );
+		Optimizer optimizer = buildNoneOptimizer( -1, -1 );
+		for ( int i = 1; i < 11; i++ ) {
+			final Long next = ( Long ) optimizer.generate( sequence );
+			assertEquals( -i, next.intValue() );
+		}
+		assertEquals( 10, sequence.getTimesCalled() );
+		assertEquals( -10, sequence.getCurrentValue() );
+
+		// test historic table behavior, where the initial values started at 0 (we now force 1 to be the first used id value)
+		sequence = new SourceMock( 0 );
+		optimizer = buildNoneOptimizer( -1, 1 );
+		for ( int i = 1; i < 11; i++ ) {
+			final Long next = ( Long ) optimizer.generate( sequence );
+			assertEquals( i, next.intValue() );
+		}
+		assertEquals( 11, sequence.getTimesCalled() ); // an extra time to get to 1 initially
+		assertEquals( 10, sequence.getCurrentValue() );
+	}
 
 	@Test
 	public void testBasicHiLoOptimizerUsage() {