Fixed extension functions being grayed in import statement completion

#KT-5627 Fixed

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/CompletionSession.kt

@@ -314,9 +314,9 @@ abstract class CompletionSession(protected val configuration: CompletionSessionC
                                     insertHandlerProvider, contextVariablesProvider)
     }
 
-    private fun detectCallTypeAndReceiverTypes(): Pair<CallType<*>, Collection<JetType>> {
+    private fun detectCallTypeAndReceiverTypes(): Pair<CallType<*>, Collection<JetType>?> {
         if (nameExpression == null) {
-            return CallType.DEFAULT to emptyList()
+            return CallType.DEFAULT to null
         }
 
         val callTypeAndReceiver = CallTypeAndReceiver.detect(nameExpression)
@@ -338,9 +338,13 @@ abstract class CompletionSession(protected val configuration: CompletionSessionC
             is CallTypeAndReceiver.SAFE -> receiverExpression = callTypeAndReceiver.receiver
             is CallTypeAndReceiver.INFIX -> receiverExpression = callTypeAndReceiver.receiver
             is CallTypeAndReceiver.UNARY -> receiverExpression = callTypeAndReceiver.receiver
-            is CallTypeAndReceiver.IMPORT_DIRECTIVE -> receiverExpression = callTypeAndReceiver.receiver
-            is CallTypeAndReceiver.PACKAGE_DIRECTIVE -> receiverExpression = callTypeAndReceiver.receiver
-            is CallTypeAndReceiver.TYPE -> receiverExpression = callTypeAndReceiver.receiver
+
+            is CallTypeAndReceiver.IMPORT_DIRECTIVE,
+            is CallTypeAndReceiver.PACKAGE_DIRECTIVE,
+            is CallTypeAndReceiver.TYPE ->
+                // we don't need to highlight immediate members in these cases
+                return callTypeAndReceiver.callType to null
+
             else -> throw RuntimeException() //TODO: see KT-9394
         }
 

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/LookupElementFactory.kt

@@ -44,7 +44,7 @@ import org.jetbrains.kotlin.types.typeUtil.isSubtypeOf
 
 class LookupElementFactory(
         private val resolutionFacade: ResolutionFacade,
-        private val receiverTypes: Collection<JetType>,
+        private val receiverTypes: Collection<JetType>?,
         private val callType: CallType<*>,
         private val isInStringTemplateAfterDollar: Boolean,
         public val insertHandlerProvider: InsertHandlerProvider,
@@ -235,6 +235,7 @@ class LookupElementFactory(
     }
 
     private fun callableWeight(descriptor: DeclarationDescriptor): CallableWeight? {
+        if (receiverTypes == null) return null
         if (descriptor !is CallableDescriptor) return null
 
         val overridden = descriptor.overriddenDescriptors

idea/idea-completion/testData/basic/multifile/InImport/InImport.dependency.kt

@@ -0,0 +1,7 @@
+package second
+
+fun String.extensionFun(){}
+val Int.extensionVal: Int get() = 1
+
+fun topLevelFun(p: (String, Int) -> Unit){}
+val topLevelVal: Int = 1

idea/idea-completion/testData/basic/multifile/InImport/InImport.kt

@@ -0,0 +1,8 @@
+package first
+
+import second.<caret>
+
+// EXIST: { itemText: "extensionFun", tailText: "() for String in second", attributes: "" }
+// EXIST: { itemText: "extensionVal", tailText: " for Int in second", attributes: "" }
+// EXIST: { itemText: "topLevelFun", tailText: "(p: (String, Int) -> Unit) (second)", attributes: "" }
+// EXIST: { itemText: "topLevelVal", tailText: " (second)", attributes: "" }

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/MultiFileJvmBasicCompletionTestGenerated.java

@@ -131,6 +131,12 @@ public class MultiFileJvmBasicCompletionTestGenerated extends AbstractMultiFileJ
         doTest(fileName);
     }
 
+    @TestMetadata("InImport")
+    public void testInImport() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/multifile/InImport/");
+        doTest(fileName);
+    }
+
     @TestMetadata("InImportedFunctionLiteralParameter")
     public void testInImportedFunctionLiteralParameter() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/basic/multifile/InImportedFunctionLiteralParameter/");