DATAMONGO-2002 - Fixed Criteria.equals(…) for usage with Pattern instances.

For Criteria instances that use regular expressions we now properly compare the two Pattern instances produced by also including the pattern flags in the comparison.

Author: odrotbohm

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/Criteria.java

@@ -794,8 +794,17 @@ private boolean isEqual(Object left, Object right) {
 			return right == null;
 		}
 
-		if (left instanceof Pattern) {
-			return right instanceof Pattern ? ((Pattern) left).pattern().equals(((Pattern) right).pattern()) : false;
+		if (Pattern.class.isInstance(left)) {
+
+			if (!Pattern.class.isInstance(right)) {
+				return false;
+			}
+
+			Pattern leftPattern = (Pattern) left;
+			Pattern rightPattern = (Pattern) right;
+
+			return leftPattern.pattern().equals(rightPattern.pattern()) //
+					&& leftPattern.flags() == rightPattern.flags();
 		}
 
 		return ObjectUtils.nullSafeEquals(left, right);

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/query/CriteriaTests.java

@@ -213,4 +213,13 @@ public void intersectsShouldWrapGeoJsonTypeInGeometryCorrectly() {
 
 		assertThat(document, isBsonObject().containing("foo.$geoIntersects.$geometry", lineString));
 	}
+
+	@Test // DATAMONGO-2002
+	public void shouldEqualForSamePattern() {
+
+		Criteria left = new Criteria("field").regex("foo", "iu");
+		Criteria right = new Criteria("field").regex("foo");
+
+		assertThat(left, is(not(right)));
+	}
 }