KtLightMemberModifierList:hasExplicitModifier("default") returns false

#KT-18070 Fixed

compiler/light-classes/src/org/jetbrains/kotlin/asJava/elements/KtLightMemberImpl.kt

@@ -79,6 +79,7 @@ private class KtLightMemberModifierList(
 ) : KtLightModifierList<KtLightMember<*>>(owner) {
     override fun hasModifierProperty(name: String) = when {
         name == PsiModifier.ABSTRACT && isImplementationInInterface() -> false
+        // pretend this method behaves like a default method
         name == PsiModifier.DEFAULT && isImplementationInInterface() -> true
         dummyDelegate != null -> {
             when {
@@ -90,6 +91,10 @@ private class KtLightMemberModifierList(
         else -> clsDelegate.hasModifierProperty(name)
     }
 
+    override fun hasExplicitModifier(name: String) =
+            // kotlin methods can't be truly default atm, that way we can avoid being reported on by diagnostics, namely android lint
+            if (name == PsiModifier.DEFAULT) false else super.hasExplicitModifier(name)
+
     private fun isMethodOverride() = owner is KtLightMethod && owner.kotlinOrigin?.hasModifier(KtTokens.OVERRIDE_KEYWORD) ?: false
 
     private fun isImplementationInInterface()

plugins/uast-kotlin/tests/KotlinUastApiTest.kt

@@ -1,5 +1,6 @@
 package org.jetbrains.uast.test.kotlin
 
+import com.intellij.psi.PsiModifier
 import org.jetbrains.kotlin.psi.KtLiteralStringTemplateEntry
 import org.jetbrains.kotlin.psi.KtStringTemplateExpression
 import org.jetbrains.kotlin.psi.psiUtil.getParentOfType
@@ -53,4 +54,12 @@ class KotlinUastApiTest : AbstractKotlinUastTest() {
             assertEquals(file.psi, xyzzy.nameIdentifier!!.containingFile)
         }
     }
+
+    @Test fun testInterfaceMethodWithBody() {
+        doTest("DefaultImpls") { _, file ->
+            val bar = file.findElementByText<UMethod>("fun bar() = \"Hello!\"")
+            assertFalse(bar.containingFile.text!!, bar.psi.modifierList.hasExplicitModifier(PsiModifier.DEFAULT))
+            assertTrue(bar.containingFile.text!!, bar.psi.modifierList.hasModifierProperty(PsiModifier.DEFAULT))
+        }
+    }
 }