Dedicated specificity comparator in PathPattern

The PathPattern compareTo method is now consistent with equals when
two patterns are of the same specificity but otherwise different.

Separately PathPattern now exposes a Comparator by specificity that
offers the current functionality of compareTo. This can be used for
actual sorting where we only care about specificity.

spring-webflux/src/test/java/org/springframework/web/reactive/result/condition/PatternsRequestConditionTests.java

@@ -137,7 +137,7 @@ public class PatternsRequestConditionTests {
 	}
 
 	@Test
-	public void compareEqualPatterns() throws Exception {
+	public void compareToConsistentWithEquals() throws Exception {
 		PatternsRequestCondition c1 = createPatternsCondition("/foo*");
 		PatternsRequestCondition c2 = createPatternsCondition("/foo*");
 
@@ -155,10 +155,17 @@ public class PatternsRequestConditionTests {
 
 	@Test
 	public void comparePatternSpecificity() throws Exception {
+		ServerWebExchange exchange = get("/foo").toExchange();
+
 		PatternsRequestCondition c1 = createPatternsCondition("/fo*");
 		PatternsRequestCondition c2 = createPatternsCondition("/foo");
 
-		assertEquals(1, c1.compareTo(c2, get("/foo").toExchange()));
+		assertEquals(1, c1.compareTo(c2, exchange));
+
+		c1 = createPatternsCondition("/fo*");
+		c2 = createPatternsCondition("/*oo");
+
+		assertEquals("Patterns are equally specific even if not the same", 0, c1.compareTo(c2, exchange));
 	}
 
 	@Test

spring-webflux/src/test/java/org/springframework/web/reactive/result/method/HandlerMethodMappingTests.java

@@ -160,7 +160,7 @@ public class HandlerMethodMappingTests {
 
 		@Override
 		protected Comparator<String> getMappingComparator(ServerWebExchange exchange) {
-			return Comparator.comparing(o -> parser.parse(o));
+			return (o1, o2) -> PathPattern.SPECIFICITY_COMPARATOR.compare(parser.parse(o1), parser.parse(o2));
 		}
 
 	}