### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core
Index: compiler/org/eclipse/jdt/internal/compiler/ast/SingleNameReference.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/SingleNameReference.java,v
retrieving revision 1.117
diff -u -r1.117 SingleNameReference.java
--- compiler/org/eclipse/jdt/internal/compiler/ast/SingleNameReference.java	7 Apr 2010 12:47:50 -0000	1.117
+++ compiler/org/eclipse/jdt/internal/compiler/ast/SingleNameReference.java	15 Jul 2010 16:33:42 -0000
@@ -77,10 +77,14 @@
 					currentScope.problemReporter().uninitializedLocalVariable(localBinding, this);
 					// we could improve error msg here telling "cannot use compound assignment on final local variable"
 				}
-				if (isReachable) {
-					localBinding.useFlag = LocalVariableBinding.USED;
-				} else if (localBinding.useFlag == LocalVariableBinding.UNUSED) {
-					localBinding.useFlag = LocalVariableBinding.FAKE_USED;
+				if (localBinding.useFlag != LocalVariableBinding.USED) {
+					// https://bugs.eclipse.org/bugs/show_bug.cgi?id=318571
+					// access from compound assignment does not prevent "unused" warning, unless unboxing is involved:
+					if (isReachable && (this.implicitConversion & TypeIds.UNBOXING) != 0) {
+						localBinding.useFlag = LocalVariableBinding.USED;
+					} else {
+						localBinding.useFlag = LocalVariableBinding.FAKE_USED;
+					}
 				}
 		}
 	}
@@ -461,6 +465,14 @@
  * are optimized in one access: e.g "a = a + 1" optimized into "a++".
  */
 public void generateCompoundAssignment(BlockScope currentScope, CodeStream codeStream, Expression expression, int operator, int assignmentImplicitConversion, boolean valueRequired) {
+	if (!valueRequired && ((this.bits & ASTNode.RestrictiveFlagMASK) == Binding.LOCAL)) {
+		LocalVariableBinding localBinding = (LocalVariableBinding) this.binding;
+		if (localBinding.useFlag == LocalVariableBinding.FAKE_USED) {
+			// report the case of a local variable that is unread except for this compound assignment
+			currentScope.problemReporter().unusedLocalVariable(localBinding.declaration);
+			localBinding.useFlag = LocalVariableBinding.USED; // don't report again
+		}
+	}
 	this.generateCompoundAssignment(
 		currentScope,
 		codeStream,
@@ -661,6 +673,15 @@
 			return;
 		case Binding.LOCAL : // assigning to a local variable
 			LocalVariableBinding localBinding = (LocalVariableBinding) this.binding;
+
+			if (!valueRequired) {
+				if (localBinding.useFlag == LocalVariableBinding.FAKE_USED) {
+					// report the case of a local variable that is unread except for postIncrement expressions
+					currentScope.problemReporter().unusedLocalVariable(localBinding.declaration);
+					localBinding.useFlag = LocalVariableBinding.USED; // don't report again
+				}
+			}
+
 			// using incr bytecode if possible
 			if (localBinding.type == TypeBinding.INT) {
 				if (valueRequired) {
#P org.eclipse.jdt.core.tests.compiler
Index: src/org/eclipse/jdt/core/tests/compiler/regression/ProgrammingProblemsTest.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/ProgrammingProblemsTest.java,v
retrieving revision 1.23
diff -u -r1.23 ProgrammingProblemsTest.java
--- src/org/eclipse/jdt/core/tests/compiler/regression/ProgrammingProblemsTest.java	14 Jul 2010 10:37:24 -0000	1.23
+++ src/org/eclipse/jdt/core/tests/compiler/regression/ProgrammingProblemsTest.java	15 Jul 2010 16:33:49 -0000
@@ -1683,4 +1683,42 @@
 		"The assignment to variable nvx has no effect\n" + 
 		"----------\n");
 }
+// https://bugs.eclipse.org/bugs/show_bug.cgi?id=185682
+public void test0046() {
+	if (this.complianceLevel < ClassFileConstants.JDK1_5)
+		return;
+	Map customOptions = getCompilerOptions();
+	customOptions.put(CompilerOptions.OPTION_ReportUnusedLocal, CompilerOptions.WARNING);
+	this.runNegativeTest(
+			new String[] {
+				"X.java",
+				"class X {\n" + 
+				"    int foo() {\n" + 
+				"        int i=1;\n" + 
+				"        boolean b=false;\n" + 
+				"        b|=true;\n" + 			// not a relevant usage
+				"        int k = 2;\n" + 
+				"        --k;\n" + 				// not a relevant usage
+				"        k+=3;\n" + 			// not a relevant usage
+				"        Integer j = 3;\n" + 
+				"        j++;\n" + 				// relevant because unboxing is involved
+				"        return i++;\n" + 		// value after increment is used
+				"    }\n" + 
+				"}"
+			},
+			"----------\n" + 
+			"1. WARNING in X.java (at line 4)\n" + 
+			"	boolean b=false;\n" + 
+			"	        ^\n" + 
+			"The local variable b is never read\n" + 
+			"----------\n" + 
+			"2. WARNING in X.java (at line 6)\n" + 
+			"	int k = 2;\n" + 
+			"	    ^\n" + 
+			"The local variable k is never read\n" + 
+			"----------\n",
+			null/*classLibraries*/,
+			true/*shouldFlushOutputDirectory*/,
+			customOptions);
+}
 }
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