Fixed Bug 406619 - [1.8][compiler] Incorrect suggestion that method can

be made static. 

2 files changed, 22 insertions, 1 deletions

diff --git a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/InterfaceMethodsTest.java b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/InterfaceMethodsTest.java
index c9f04f94df..5ec8f8788e 100644
--- a/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/InterfaceMethodsTest.java
+++ b/org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/InterfaceMethodsTest.java
@@ -18,6 +18,7 @@ package org.eclipse.jdt.core.tests.compiler.regression;
 import java.util.Map;
 
 import org.eclipse.jdt.core.JavaCore;
+import org.eclipse.jdt.internal.compiler.impl.CompilerOptions;
 
 import junit.framework.Test;
 
@@ -1742,6 +1743,26 @@ public class InterfaceMethodsTest extends AbstractComparableTest {
 				"Cannot use super in a static context\n" + 
 				"----------\n");
 	}
+    // https://bugs.eclipse.org/bugs/show_bug.cgi?id=406619, [1.8][compiler] Incorrect suggestion that method can be made static.
+	public void test406619() {
+		Map compilerOptions = getCompilerOptions();
+		compilerOptions.put(CompilerOptions.OPTION_ReportMethodCanBeStatic, CompilerOptions.ERROR);
+		compilerOptions.put(CompilerOptions.OPTION_ReportMethodCanBePotentiallyStatic, CompilerOptions.ERROR);
+		this.runNegativeTest(
+			new String[] {
+				"X.java", 
+				"interface X {\n" +
+				"	default int foo() {\n" +
+				"		return 10;\n" +
+				"	}\n" +
+				"}\n"
+			},
+			"",
+			null /* no extra class libraries */,
+			true /* flush output directory */,
+			compilerOptions /* custom options */
+		);
+	}
 
 	// class implements interface with default method. 
 	// - synth. access needed for visibility reasons
diff --git a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/MethodDeclaration.java b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/MethodDeclaration.java
index c68500dd4e..f6aacc792e 100644
--- a/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/MethodDeclaration.java
+++ b/org.eclipse.jdt.core/compiler/org/eclipse/jdt/internal/compiler/ast/MethodDeclaration.java
@@ -145,7 +145,7 @@ public class MethodDeclaration extends AbstractMethodDeclaration {
 			// check unused parameters
 			this.scope.checkUnusedParameters(this.binding);
 			// check if the method could have been static
-			if (!this.binding.isStatic() && (this.bits & ASTNode.CanBeStatic) != 0) {
+			if (!this.binding.isStatic() && (this.bits & ASTNode.CanBeStatic) != 0 && !this.isDefaultMethod()) {
 				if(!this.binding.isOverriding() && !this.binding.isImplementing()) {
 					if (this.binding.isPrivate() || this.binding.isFinal() || this.binding.declaringClass.isFinal()) {
 						this.scope.problemReporter().methodCanBeDeclaredStatic(this);