From 64caad04a37c7e7bd588f48bf981ea1d36d9d4bf Mon Sep 17 00:00:00 2001
From: Oliver Gierke <ogierke@gopivotal.com>
Date: Mon, 14 Apr 2014 21:49:25 +0200
Subject: [PATCH] DATACMNS-485 - Fixed false negative type alias detection in
 MappingContextTypeInformationMapper.

MappingContextTypeInformationMapper now considers the raw type only for type alias conflict detection.
---
 .../MappingContextTypeInformationMapper.java  | 26 ++++++++++++--
 ...ContextTypeInformationMapperUnitTests.java | 35 +++++++++++++++++++
 2 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/src/main/java/org/springframework/data/convert/MappingContextTypeInformationMapper.java b/src/main/java/org/springframework/data/convert/MappingContextTypeInformationMapper.java
index b3adb5a26..15fcde8f5 100644
--- a/src/main/java/org/springframework/data/convert/MappingContextTypeInformationMapper.java
+++ b/src/main/java/org/springframework/data/convert/MappingContextTypeInformationMapper.java
@@ -21,6 +21,7 @@ import java.util.Map.Entry;
 
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.context.MappingContext;
+import org.springframework.data.util.ClassTypeInformation;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.util.Assert;
 
@@ -90,12 +91,31 @@ public class MappingContextTypeInformationMapper implements TypeInformationMappe
 			return;
 		}
 
-		if (typeMap.containsValue(alias)) {
+		TypeInformation<?> toStore = ClassTypeInformation.from(key.getType());
+		Object existingAlias = typeMap.get(toStore);
+
+		// Reject second alias for same type
+
+		if (existingAlias != null && !alias.equals(existingAlias)) {
 			throw new IllegalArgumentException(String.format(
-					"Detected mapping ambiguity! String %s cannot be mapped to more than one type!", alias));
+					"Trying to register alias '%s', but found already registered alias '%s' for type %s!", alias, existingAlias,
+					toStore));
 		}
 
-		typeMap.put(key, alias);
+		// Reject second type for same alias
+
+		if (typeMap.containsValue(alias)) {
+
+			for (Entry<TypeInformation<?>, Object> entry : typeMap.entrySet()) {
+				if (entry.getValue().equals(alias) && !entry.getKey().equals(toStore)) {
+					throw new IllegalArgumentException(String.format(
+							"Detected existing type mapping of %s to alias '%s' but attempted to bind the same alias to %s!",
+							toStore, alias, entry.getKey()));
+				}
+			}
+		}
+
+		typeMap.put(toStore, alias);
 	}
 
 	/*
diff --git a/src/test/java/org/springframework/data/convert/MappingContextTypeInformationMapperUnitTests.java b/src/test/java/org/springframework/data/convert/MappingContextTypeInformationMapperUnitTests.java
index 549fc5520..85350f413 100644
--- a/src/test/java/org/springframework/data/convert/MappingContextTypeInformationMapperUnitTests.java
+++ b/src/test/java/org/springframework/data/convert/MappingContextTypeInformationMapperUnitTests.java
@@ -27,6 +27,7 @@ import org.springframework.data.annotation.TypeAlias;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.context.SampleMappingContext;
 import org.springframework.data.mapping.context.SamplePersistentProperty;
+import org.springframework.data.util.AnnotatedTypeScanner;
 import org.springframework.data.util.ClassTypeInformation;
 import org.springframework.data.util.TypeInformation;
 
@@ -98,8 +99,42 @@ public class MappingContextTypeInformationMapperUnitTests {
 		assertThat(mapper.resolveTypeFrom("foo"), is((TypeInformation) from(Entity.class)));
 	}
 
+	/**
+	 * @see DATACMNS-485
+	 */
+	@Test
+	@SuppressWarnings("unchecked")
+	public void createsTypeMapperForGenericTypesWithDifferentBindings() {
+
+		AnnotatedTypeScanner scanner = new AnnotatedTypeScanner(TypeAlias.class);
+
+		SampleMappingContext context = new SampleMappingContext();
+		context.setInitialEntitySet(scanner.findTypes(getClass().getPackage().getName()));
+		context.initialize();
+
+		new MappingContextTypeInformationMapper(context);
+	}
+
 	@TypeAlias("foo")
 	static class Entity {
 
 	}
+
+	@TypeAlias("genericType")
+	static class GenericType<T> {
+
+	}
+
+	@TypeAlias("concreteWrapper")
+	static class ConcreteWrapper {
+
+		GenericType<String> stringGeneric;
+		GenericType<Integer> integerGeneric;
+	}
+
+	@TypeAlias("genericWrapper")
+	static class GenericWrapper<T> {
+
+		GenericType<T> genericGeneric;
+	}
 }