### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core
Index: compiler/org/eclipse/jdt/internal/compiler/lookup/MethodVerifier15.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/MethodVerifier15.java,v
retrieving revision 1.74
diff -u -r1.74 MethodVerifier15.java
--- compiler/org/eclipse/jdt/internal/compiler/lookup/MethodVerifier15.java	17 Apr 2007 14:34:08 -0000	1.74
+++ compiler/org/eclipse/jdt/internal/compiler/lookup/MethodVerifier15.java	23 Apr 2007 06:50:08 -0000
@@ -769,6 +769,17 @@
 	return copy;
 }
 boolean reportIncompatibleReturnTypeError(MethodBinding currentMethod, MethodBinding inheritedMethod) {
+	// JLS 3 §8.4.5: more are accepted, with an unchecked conversion
+	if (currentMethod.returnType == inheritedMethod.returnType.erasure()) {
+		TypeBinding[] currentParams = currentMethod.parameters;
+		TypeBinding[] inheritedParams = inheritedMethod.parameters;
+		for (int i = 0, l = currentParams.length; i < l; i++) {
+			if (!areTypesEqual(currentParams[i], inheritedParams[i])) {
+				problemReporter(currentMethod).unsafeReturnTypeOverride(currentMethod, inheritedMethod, this.type);
+				return false;
+			}
+		}
+	}
 	if (currentMethod.typeVariables == Binding.NO_TYPE_VARIABLES
 		&& inheritedMethod.original().typeVariables != Binding.NO_TYPE_VARIABLES
 		&& currentMethod.returnType.erasure().findSuperTypeWithSameErasure(inheritedMethod.returnType.erasure()) != null) {
Index: compiler/org/eclipse/jdt/internal/compiler/lookup/MethodVerifier.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/lookup/MethodVerifier.java,v
retrieving revision 1.83
diff -u -r1.83 MethodVerifier.java
--- compiler/org/eclipse/jdt/internal/compiler/lookup/MethodVerifier.java	17 Apr 2007 14:34:09 -0000	1.83
+++ compiler/org/eclipse/jdt/internal/compiler/lookup/MethodVerifier.java	23 Apr 2007 06:50:08 -0000
@@ -627,6 +627,16 @@
 SimpleSet findSuperinterfaceCollisions(ReferenceBinding superclass, ReferenceBinding[] superInterfaces) {
 	return null; // noop in 1.4
 }
+/**
+ * Return true and report an incompatibleReturnType error if currentMethod's
+ * return type is strictly incompatible with inheritedMethod's, else return 
+ * false and report an unchecked conversion warning. Do not call when
+ * areReturnTypesCompatible(currentMethod, inheritedMethod) returns true.
+ * @param currentMethod the (potentially) inheriting method
+ * @param inheritedMethod the inherited method
+ * @return true if currentMethod's return type is strictly incompatible with
+ *         inheritedMethod's
+ */
 boolean reportIncompatibleReturnTypeError(MethodBinding currentMethod, MethodBinding inheritedMethod) {
 	problemReporter(currentMethod).incompatibleReturnType(currentMethod, inheritedMethod);
 	return true;
#P org.eclipse.jdt.core.tests.compiler
Index: src/org/eclipse/jdt/core/tests/compiler/regression/MethodVerifyTest.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/MethodVerifyTest.java,v
retrieving revision 1.121
diff -u -r1.121 MethodVerifyTest.java
--- src/org/eclipse/jdt/core/tests/compiler/regression/MethodVerifyTest.java	28 Mar 2007 04:52:16 -0000	1.121
+++ src/org/eclipse/jdt/core/tests/compiler/regression/MethodVerifyTest.java	23 Apr 2007 06:50:19 -0000
@@ -5302,18 +5302,16 @@
 			// warning: create() in HashOrder overrides <U>create() in DoubleHash; return type requires unchecked conversion
 		);
 	}
-	//https://bugs.eclipse.org/bugs/show_bug.cgi?id=125956
-	public void test081() {
+	// https://bugs.eclipse.org/bugs/show_bug.cgi?id=125956
+	public void test081a() {
 		this.runNegativeTest(
 			new String[] {
 				"X.java",
 				"public abstract class X<U> implements I {\n" +
 				"	public A<String> foo() { return null; }\n" +
-				"	public <S> A<U> bar() { return null; }\n" +
 				"}\n" +
 				"interface I {\n" +
 				"	<T> A<T> foo();\n" +
-				"	<S> A<S> bar();\n" +
 				"}\n" +
 				"class A<V> {}"
 			},
@@ -5322,14 +5320,28 @@
 			"	public A<String> foo() { return null; }\r\n" + 
 			"	       ^\n" + 
 			"Type safety: The return type A<String> for foo() from the type X<U> needs unchecked conversion to conform to A<Object> from the type I\n" + 
+			"----------\n"
+		);
+	}
+	// https://bugs.eclipse.org/bugs/show_bug.cgi?id=125956
+	public void test081b() {
+		this.runNegativeTest(
+			new String[] {
+				"X.java",
+				"public abstract class X<U> implements I {\n" +
+				"	public <S> A<U> bar() { return null; }\n" +
+				"}\n" +
+				"interface I {\n" +
+				"	<S> A<S> bar();\n" +
+				"}\n" +
+				"class A<V> {}"
+			},
 			"----------\n" + 
-			"2. ERROR in X.java (at line 3)\r\n" + 
+			"1. ERROR in X.java (at line 2)\r\n" + 
 			"	public <S> A<U> bar() { return null; }\r\n" + 
 			"	           ^^^^\n" + 
 			"The return type is incompatible with I.bar()\n" + 
 			"----------\n"
-			// <S>bar() in X cannot implement <S>bar() in I; attempting to use incompatible return type
-			// warning: foo() in X implements <T>foo() in I; return type requires unchecked conversion
 		);
 	}
 	//https://bugs.eclipse.org/bugs/show_bug.cgi?id=105339
@@ -7544,4 +7556,368 @@
 		"Type safety: The return type Enum<?> for foo() from the type X.B needs unchecked conversion to conform to U from the type X.A<T>\n" + 
 		"----------\n");
 }
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+public void test128() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"interface I<U, V> {\n" + 
+			"  U foo(Object o, V v);\n" + 
+			"}\n" + 
+			"public class X<U, V> implements I<U, V> {\n" + 
+			"  public Object foo(Object o, Object v) {\n" + 
+			"    return null;\n" + 
+			"  }\n" + 
+			"}\n"
+		},
+		"----------\n" + 
+		"1. WARNING in X.java (at line 5)\n" + 
+		"	public Object foo(Object o, Object v) {\n" + 
+		"	       ^^^^^^\n" + 
+		"Type safety: The return type Object for foo(Object, Object) from the type X<U,V> needs unchecked conversion to conform to U from the type I<U,V>\n" + 
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant - Object is not a subtype of Z
+public void test129() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"interface I<U, V> {\n" + 
+			"  U foo(Object o, V v);\n" + 
+			"}\n" + 
+			"public class X<U extends Z, V> implements I<U, V> {\n" + 
+			"  public Object foo(Object o, Object v) {\n" + 
+			"    return null;\n" + 
+			"  }\n" + 
+			"}\n" + 
+			"class Z {\n" + 
+			"}\n"
+		},
+		"----------\n" + 
+		"1. ERROR in X.java (at line 5)\n" + 
+		"	public Object foo(Object o, Object v) {\n" + 
+		"	       ^^^^^^\n" + 
+		"The return type is incompatible with I<U,V>.foo(Object, V)\n" + 
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// ** variant - Z<Object> is not a subtype of Z<U>, and |Z<U>| = Z, not Z<Object>
+public void test130() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"interface I<U, V> {\n" + 
+			"  Z<U> foo(Object o, V v);\n" + 
+			"}\n" + 
+			"public class X<U, V> implements I<U, V> {\n" + 
+			"  public Z<Object> foo(Object o, Object v) {\n" + 
+			"    return null;\n" + 
+			"  }\n" + 
+			"}\n" + 
+			"class Z<T> {\n" + 
+			"}"
+		},
+		"----------\n" + 
+		"1. ERROR in X.java (at line 5)\n" + 
+		"	public Z<Object> foo(Object o, Object v) {\n" + 
+		"	       ^^^^^^^^^\n" + 
+		"The return type is incompatible with I<U,V>.foo(Object, V)\n" + 
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant - two interfaces
+public void test131() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"interface I<U, V> {\n" + 
+			"  U foo(Object o, V v);\n" + 
+			"}\n" + 
+			"interface X<U, V> extends I<U, V> {\n" + 
+			"  Object foo(Object o, Object v);\n" + 
+			"}\n"
+		},
+		"----------\n" + 
+		"1. WARNING in X.java (at line 5)\n" + 
+		"	Object foo(Object o, Object v);\n" + 
+		"	^^^^^^\n" + 
+		"Type safety: The return type Object for foo(Object, Object) from the type X<U,V> needs unchecked conversion to conform to U from the type I<U,V>\n" + 
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant - simpler test case
+public void test132() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"interface I<U> {\n" + 
+			"  U foo();\n" + 
+			"}\n" + 
+			"public class X<U> implements I<U> {\n" + 
+			"  public Object foo() {\n" + 
+			"    return null;\n" + 
+			"  }\n" + 
+			"}\n"
+		},
+		"----------\n" + 
+		"1. ERROR in X.java (at line 5)\n" + 
+		"	public Object foo() {\n" + 
+		"	       ^^^^^^\n" + 
+		"The return type is incompatible with I<U>.foo()\n" + 
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant
+public void test133() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"public class X<U extends Z> {\n" + 
+			"  U foo() {\n" + 
+			"    return null;\n" + 
+			"  }\n" + 
+			"}\n" + 
+			"class Y<U extends Z> extends X<U> {\n" + 
+			"  public Z foo() {\n" + 
+			"    return null;\n" + 
+			"  }\n" + 
+			"}\n" + 
+			"class Z {\n" + 
+			"}"
+		},
+		"----------\n" + 
+		"1. ERROR in X.java (at line 7)\n" + 
+		"	public Z foo() {\n" + 
+		"	       ^\n" + 
+		"The return type is incompatible with X<U>.foo()\n" + 
+		"----------\n" + 
+		"2. WARNING in X.java (at line 7)\n" + 
+		"	public Z foo() {\n" + 
+		"	         ^^^^^\n" + 
+		"The method foo() of type Y<U> should be tagged with @Override since it actually overrides a superclass method\n" + 
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant - unchecked conversion of ZC to ZC<String> that is a subtype of Z<String> 
+public void test134() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"public class X {\n" + 
+			"  Z<String> foo() {\n" + 
+			"    return null;\n" + 
+			"  }\n" + 
+			"}\n" + 
+			"class Y extends X {\n" + 
+			"  public ZC foo() {\n" + 
+			"    return null;\n" + 
+			"  }\n" + 
+			"}\n" + 
+			"class Z<T> {\n" + 
+			"}\n" + 
+			"class ZC<T> extends Z<T> {\n" + 
+			"}"
+		},
+		"----------\n" + 
+		"1. WARNING in X.java (at line 7)\n" + 
+		"	public ZC foo() {\n" + 
+		"	       ^^\n" + 
+		"ZC is a raw type. References to generic type ZC<T> should be parameterized\n" + 
+		"----------\n" + 
+		"2. WARNING in X.java (at line 7)\n" + 
+		"	public ZC foo() {\n" + 
+		"	       ^^\n" + 
+		"Type safety: The return type ZC for foo() from the type Y needs unchecked conversion to conform to Z<String> from the type X\n" + 
+		"----------\n" + 
+		"3. WARNING in X.java (at line 7)\n" + 
+		"	public ZC foo() {\n" + 
+		"	          ^^^^^\n" + 
+		"The method foo() of type Y should be tagged with @Override since it actually overrides a superclass method\n" + 
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant - cast is not appropriate
+public void test135() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"interface I<U, V> {\n" + 
+			"  U foo(Object o, V v);\n" + 
+			"}\n" + 
+			"interface J<U, V> extends I<U, V> {\n" + 
+			"  Object foo(Object o, V v);\n" + 
+			"}\n" + 
+			"class X {\n" + 
+			"  J<Integer, Integer> m1;\n" + 
+			"  I<Integer, Integer> m2 = (I<Integer, Integer>) m1;\n" + 
+			"}"
+		},
+		"----------\n" + 
+		"1. ERROR in X.java (at line 5)\n" + 
+		"	Object foo(Object o, V v);\n" + 
+		"	^^^^^^\n" + 
+		"The return type is incompatible with I<U,V>.foo(Object, V)\n" + 
+		"----------\n" + 
+		"2. WARNING in X.java (at line 9)\n" + 
+		"	I<Integer, Integer> m2 = (I<Integer, Integer>) m1;\n" + 
+		"	                         ^^^^^^^^^^^^^^^^^^^^^^^^\n" + 
+		"Unnecessary cast from J<Integer,Integer> to I<Integer,Integer>\n" + 
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant - type identity vs type equivalence
+public void test136() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"interface I<U> {\n" + 
+			"  U foo(I<?> p);\n" + 
+			"}\n" + 
+			"public class X<U> implements I<U> {\n" + 
+			"  public Object foo(I<? extends Object> p) {\n" + 
+			"    return null;\n" + 
+			"  }\n" + 
+			"}\n"
+		},
+		"----------\n" + 
+		"1. ERROR in X.java (at line 5)\n" + 
+		"	public Object foo(I<? extends Object> p) {\n" + 
+		"	       ^^^^^^\n" + 
+		"The return type is incompatible with I<U>.foo(I<?>)\n" + 
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant - type identity vs type equivalence
+public void test137() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"interface I<U> {\n" + 
+			"  U foo(I<? extends Object> p);\n" + 
+			"}\n" + 
+			"public class X<U> implements I<U> {\n" + 
+			"  public Object foo(I<?> p) {\n" + 
+			"    return null;\n" + 
+			"  }\n" + 
+			"}\n"
+		},
+		"----------\n" + 
+		"1. ERROR in X.java (at line 5)\n" + 
+		"	public Object foo(I<?> p) {\n" + 
+		"	       ^^^^^^\n" + 
+		"The return type is incompatible with I<U>.foo(I<? extends Object>)\n" + 
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant - @Override annotation
+public void test138() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"public class X<U> {\n" + 
+			"  U foo() { return null; }\n" + 
+			"}\n" + 
+			"class Y<U> extends X<U> {\n" + 
+			"  @Override // does not override error\n" + 
+			"  Object foo() { return null; } // cannot override foo(), incompatible return type error\n" + 
+			"}"
+		},
+		"----------\n" + 
+		"1. ERROR in X.java (at line 6)\n" + 
+		"	Object foo() { return null; } // cannot override foo(), incompatible return type error\n" + 
+		"	^^^^^^\n" + 
+		"The return type is incompatible with X<U>.foo()\n" + 
+		"----------\n");
+}// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant - @Override annotation
+public void test139() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"public class X<U> {\n" + 
+			"  U foo(U one) { return null; }\n" + 
+			"}\n" + 
+			"class Y<U> extends X<U> {\n" + 
+			"  @Override\n" + 
+			"  Object foo(Object one) { return null; } // unchecked conversion warning\n" + 
+			"}"
+		},
+		"----------\n" + 
+		"1. WARNING in X.java (at line 6)\n" + 
+		"	Object foo(Object one) { return null; } // unchecked conversion warning\n" + 
+		"	^^^^^^\n" + 
+		"Type safety: The return type Object for foo(Object) from the type Y<U> needs unchecked conversion to conform to U from the type X<U>\n" + 
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant - @Override annotation
+public void test140() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"public class X<U> {\n" + 
+			"  U foo(U one, U two) { return null; }\n" + 
+			"}\n" + 
+			"class Y<U> extends X<U> {\n" + 
+			"  @Override // does not override error\n" + 
+			"  Object foo(Object one, U two) { return null; }\n" + 
+			"}"
+		},
+		"----------\n" + 
+		"1. ERROR in X.java (at line 6)\n" + 
+		"	Object foo(Object one, U two) { return null; }\n" + 
+		"	       ^^^^^^^^^^^^^^^^^^^^^^\n" + 
+		"Name clash: The method foo(Object, U) of type Y<U> has the same erasure as foo(U, U) of type X<U> but does not override it\n" + 
+		"----------\n" + 
+		"2. ERROR in X.java (at line 6)\n" + 
+		"	Object foo(Object one, U two) { return null; }\n" + 
+		"	       ^^^^^^^^^^^^^^^^^^^^^^\n" + 
+		(complianceLevel.compareTo(COMPLIANCE_1_5) <= 0 ?
+				"The method foo(Object, U) of type Y<U> must override a superclass method\n" :
+					"The method foo(Object, U) of type Y<U> must override or implement a supertype method\n") +
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant - @Override annotation
+public void test141() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"public class X<U> {\n" + 
+			"  U foo(U one) { return null; }\n" + 
+			"}\n" + 
+			"class Y<U> extends X<U> {\n" + 
+			"  @Override // does not override error\n" + 
+			"  Object foo(U one) { return null; } // cannot override foo(U), incompatible return type error\n" + 
+			"}"
+		},
+		"----------\n" + 
+		"1. ERROR in X.java (at line 6)\n" + 
+		"	Object foo(U one) { return null; } // cannot override foo(U), incompatible return type error\n" + 
+		"	^^^^^^\n" + 
+		"The return type is incompatible with X<U>.foo(U)\n" + 
+		"----------\n");
+}
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=180789
+// variant - @Override annotation
+public void test142() {
+	this.runNegativeTest(
+		new String[] {
+			"X.java",
+			"public class X<U> {\n" + 
+			"  U foo(U one, U two) { return null; }\n" + 
+			"}\n" + 
+			"class Y<U> extends X<U> {\n" + 
+			"  @Override // does not override error\n" + 
+			"  Object foo(U one, U two) { return null; } // cannot override foo(U,U), incompatible return type error\n" + 
+			"}"
+		},
+		"----------\n" + 
+		"1. ERROR in X.java (at line 6)\n" + 
+		"	Object foo(U one, U two) { return null; } // cannot override foo(U,U), incompatible return type error\n" + 
+		"	^^^^^^\n" + 
+		"The return type is incompatible with X<U>.foo(U, U)\n" + 
+		"----------\n");
+}
 }
Index: src/org/eclipse/jdt/core/tests/compiler/regression/GenericTypeTest.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/GenericTypeTest.java,v
retrieving revision 1.612
diff -u -r1.612 GenericTypeTest.java
--- src/org/eclipse/jdt/core/tests/compiler/regression/GenericTypeTest.java	20 Apr 2007 23:30:56 -0000	1.612
+++ src/org/eclipse/jdt/core/tests/compiler/regression/GenericTypeTest.java	23 Apr 2007 06:50:17 -0000
@@ -11175,7 +11175,7 @@
 			                ^
 			 */
 	}
-	public void test0384() {
+	public void test0384a() {
 		this.runConformTest(
 			new String[] {
 				"X.java",
@@ -11191,6 +11191,8 @@
 				"}\n"
 			},
 			"");
+	}
+	public void test0384b() {
 		this.runNegativeTest(
 			new String[] {
 				"X.java",
@@ -11215,7 +11217,6 @@
 			"The return type is incompatible with Y.foo2()\n" + 
 			"----------\n");
 	}
-
 	// https://bugs.eclipse.org/bugs/show_bug.cgi?id=77496
 	public void test0385() { 
 		this.runNegativeTest(