Don't suggest non-stable parameter names in completion

idea/src/org/jetbrains/jet/plugin/completion/KotlinNamedParametersContributor.kt

@@ -88,6 +88,8 @@ public class KotlinNamedParametersContributor : CompletionContributor() {
         val functionDescriptors = callReference.resolveToDescriptors().map { it as? FunctionDescriptor }.filterNotNull()
 
         for (funDescriptor in functionDescriptors) {
+            if (!funDescriptor.hasStableParameterNames()) continue
+
             val usedArguments = QuickFixUtil.getUsedParameters(callElement, valueArgument, funDescriptor)
 
             for (parameter in funDescriptor.getValueParameters()) {

idea/testData/completion/basic/custom/JavaMethodNamedArguments.kt

@@ -0,0 +1,6 @@
+import lib.JavaClass
+
+fun test() = JavaClass().foo(<caret>)
+
+// ABSENT: p0
+// ABSENT: paramName

idea/testData/completion/basic/custom/JavaMethodNamedArgumentsSrc/JavaClass.java

@@ -0,0 +1,5 @@
+package lib;
+
+public class JavaClass {
+    public void foo(int paramName) {}
+}

idea/tests/org/jetbrains/jet/completion/JvmWithLibBasicCompletionTestGenerated.java

@@ -36,6 +36,11 @@ public class JvmWithLibBasicCompletionTestGenerated extends AbstractJvmWithLibBa
         JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.generators.tests.TestsPackage", new File("idea/testData/completion/basic/custom"), Pattern.compile("^(.+)\\.kt$"), false);
     }
     
+    @TestMetadata("JavaMethodNamedArguments.kt")
+    public void testJavaMethodNamedArguments() throws Exception {
+        doTest("idea/testData/completion/basic/custom/JavaMethodNamedArguments.kt");
+    }
+    
     @TestMetadata("TopLevelNonImportedExtFun.kt")
     public void testTopLevelNonImportedExtFun() throws Exception {
         doTest("idea/testData/completion/basic/custom/TopLevelNonImportedExtFun.kt");