Add accessors: determine header properties more correctly

Related to KT-17322

idea/src/org/jetbrains/kotlin/idea/intentions/AddAccessorIntentions.kt

@@ -19,6 +19,8 @@ package org.jetbrains.kotlin.idea.intentions
 import com.intellij.codeInsight.intention.LowPriorityAction
 import com.intellij.openapi.editor.Editor
 import com.intellij.openapi.util.TextRange
+import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
+import org.jetbrains.kotlin.idea.caches.resolve.resolveToDescriptorIfAny
 import org.jetbrains.kotlin.idea.refactoring.isAbstract
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.KtProperty
@@ -32,10 +34,12 @@ abstract class AbstractAddAccessorsIntention(
     override fun applicabilityRange(element: KtProperty): TextRange? {
         if (element.isLocal || element.isAbstract() || element.hasDelegate() ||
             element.hasModifier(KtTokens.LATEINIT_KEYWORD) ||
-            element.hasModifier(KtTokens.HEADER_KEYWORD) ||
             element.hasModifier(KtTokens.CONST_KEYWORD)) {
             return null
         }
+        val descriptor = element.resolveToDescriptorIfAny() as? CallableMemberDescriptor ?: return null
+        if (descriptor.isHeader) return null
+
         if (addSetter && (!element.isVar || element.setter != null)) return null
         if (addGetter && element.getter != null) return null
         return element.nameIdentifier?.textRange

idea/testData/intentions/addPropertyAccessors/getter/header.kt

@@ -0,0 +1,6 @@
+// SKIP_ERRORS_BEFORE
+// SKIP_ERRORS_AFTER
+// IS_APPLICABLE: false
+header class Header {
+    val <caret>x: Int
+}

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java

@@ -853,6 +853,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("header.kt")
+            public void testHeader() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/addPropertyAccessors/getter/header.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("lateinit.kt")
             public void testLateinit() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/addPropertyAccessors/getter/lateinit.kt");