Index: org/eclipse/jdt/core/compiler/IProblem.java
===================================================================
RCS file: /home/eclipse/org.eclipse.jdt.core/compiler/org/eclipse/jdt/core/compiler/IProblem.java,v
retrieving revision 1.23
diff -u -r1.23 IProblem.java
--- org/eclipse/jdt/core/compiler/IProblem.java	30 Sep 2002 14:26:01 -0000	1.23
+++ org/eclipse/jdt/core/compiler/IProblem.java	8 Nov 2002 16:41:57 -0000
@@ -489,4 +489,6 @@
 	// detected task
 	/** @since 2.1 */
 	int Task = Internal + 450;
+	
+	int NoOpAssignment = 498; 
 }
Index: org/eclipse/jdt/internal/compiler/ast/Assignment.java
===================================================================
RCS file: /home/eclipse/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/Assignment.java,v
retrieving revision 1.22
diff -u -r1.22 Assignment.java
--- org/eclipse/jdt/internal/compiler/ast/Assignment.java	21 Oct 2002 14:21:55 -0000	1.22
+++ org/eclipse/jdt/internal/compiler/ast/Assignment.java	8 Nov 2002 16:41:58 -0000
@@ -19,7 +19,7 @@
 
 	public Reference lhs;
 	public Expression expression;
-	
+	public TypeBinding lhsType;	
 	public Assignment(Expression lhs, Expression expression, int sourceEnd) {
 		//lhs is always a reference by construction ,
 		//but is build as an expression ==> the checkcast cannot fail
@@ -69,6 +69,8 @@
 		if (this.resolvedType == null || rhsType == null)
 			return null;
 
+		checkNoOp(scope);
+
 		// Compile-time conversion of base-types : implicit narrowing integer into byte/short/character
 		// may require to widen the rhs expression at runtime
 		if ((expression.isConstantValueOfTypeAssignableToType(rhsType, this.resolvedType)
@@ -84,6 +86,26 @@
 		return null;
 	}
 
+	Binding getBinding(Expression ref) {
+		if (ref instanceof FieldReference) {
+			return ((Reference)ref).fieldBinding();
+		} else if (ref instanceof NameReference) {
+			return ((NameReference)ref).binding;
+		}
+		return null;
+	}
+
+	private void checkNoOp(BlockScope scope) {
+		
+		Binding lhsBinding = getBinding(lhs);
+		Binding rhsBinding = getBinding(expression);
+		if (lhsBinding == rhsBinding) {
+			scope.problemReporter().noOpAssignment(this);
+		}
+	}
+	
+		
+	
 	public String toString(int tab) {
 
 		//no () when used as a statement 
Index: org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java
===================================================================
RCS file: /home/eclipse/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java,v
retrieving revision 1.58
diff -u -r1.58 ProblemReporter.java
--- org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java	27 Oct 2002 17:39:48 -0000	1.58
+++ org/eclipse/jdt/internal/compiler/problem/ProblemReporter.java	8 Nov 2002 16:42:11 -0000
@@ -549,7 +549,10 @@
 			if ((warningThreshold & CompilerOptions.StaticAccessReceiver) != 0){
 				return Warning;
 			}
-			return Ignore;		
+			return Ignore;
+		case IProblem.NoOpAssignment:
+			return Warning;
+				
 		case IProblem.Task :
 			return Warning;			
 		default:
@@ -2631,6 +2634,16 @@
 		location.sourceStart,
 		location.sourceEnd);
 }
+
+public void noOpAssignment(Assignment assignment) {
+	this.handle(
+		IProblem.NoOpAssignment,
+		new String[] {assignment.lhs.toString(), assignment.expression.toString()},
+		new String[] {assignment.toString() },
+		assignment.sourceStart,
+		assignment.sourceEnd);
+}
+
 public void typeMismatchErrorActualTypeExpectedType(Expression expression, TypeBinding constantType, TypeBinding expectedType) {
 	String constantTypeName = new String(constantType.readableName());
 	String expectedTypeName = new String(expectedType.readableName());
Index: org/eclipse/jdt/internal/compiler/problem/messages.properties
===================================================================
RCS file: /home/eclipse/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/problem/messages.properties,v
retrieving revision 1.33
diff -u -r1.33 messages.properties
--- org/eclipse/jdt/internal/compiler/problem/messages.properties	14 Oct 2002 12:36:06 -0000	1.33
+++ org/eclipse/jdt/internal/compiler/problem/messages.properties	8 Nov 2002 16:42:01 -0000
@@ -268,4 +268,6 @@
 
 440 = ''assert'' should not be used as an identifier, since it is a reserved keyword from source level 1.4 on
 
-450 = {0} {1}
\ No newline at end of file
+450 = {0} {1}
+
+498 = The {0} assignment is a no-op