Consistent ordering for @PropertySource locations

Ensure that property source locations are processed in the same order
regardless if the 'name' attribute is set or not.

Prior to this commit multiple locations from a `@PropertySource` with
a name were added to a `CompositePropertySource` in such a way that
the first location would take precedence. This has now been reversed
for consistence with unnamed `@PropertySource`s

Issue: SPR-10820

spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClassParser.java

@@ -320,8 +320,8 @@ class ConfigurationClassParser {
 			}
 			else {
 				CompositePropertySource ps = new CompositePropertySource(name);
-				for (String location : locations) {
-					ps.addPropertySource(new ResourcePropertySource(location, classLoader));
+				for (int i = locations.length - 1; i >= 0; i--) {
+					ps.addPropertySource(new ResourcePropertySource(locations[i], classLoader));
 				}
 				this.propertySources.push(ps);
 			}

spring-context/src/test/java/org/springframework/context/annotation/PropertySourceAnnotationTests.java

@@ -130,6 +130,18 @@ public class PropertySourceAnnotationTests {
 		assertThat(ctx.getEnvironment().containsProperty("from.p2"), is(true));
 	}
 
+	/**
+	 * SPR-10820
+	 */
+	@Test
+	public void orderingWithAndWithoutNameAndMultipleResourceLocations() {
+		// p2 should 'win' as it was registered last
+		AnnotationConfigApplicationContext ctxWithName = new AnnotationConfigApplicationContext(ConfigWithNameAndMultipleResourceLocations.class);
+		AnnotationConfigApplicationContext ctxWithoutName = new AnnotationConfigApplicationContext(ConfigWithMultipleResourceLocations.class);
+		assertThat(ctxWithoutName.getEnvironment().getProperty("testbean.name"), equalTo("p2TestBean"));
+		assertThat(ctxWithName.getEnvironment().getProperty("testbean.name"), equalTo("p2TestBean"));
+	}
+
 	@Test(expected=IllegalArgumentException.class)
 	public void withEmptyResourceLocations() {
 		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
@@ -209,6 +221,15 @@ public class PropertySourceAnnotationTests {
 	static class ConfigWithNameAndMultipleResourceLocations {
 	}
 
+	@Configuration
+	@PropertySource(
+			value = {
+					"classpath:org/springframework/context/annotation/p1.properties",
+					"classpath:org/springframework/context/annotation/p2.properties"
+			})
+	static class ConfigWithMultipleResourceLocations {
+	}
+
 
 	@Configuration
 	@PropertySource(value = {})