No need to specially handle extensions from current file anymore (since searchScope for KotlinIndicesHelper includes current file)

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

@@ -149,7 +149,7 @@ class BasicCompletionSession(
             }
 
             if (callTypeAndReceiver.shouldCompleteCallableExtensions()) {
-                filter = filter.exclude(topLevelExtensionsExclude) // completed via indices
+                filter = filter.exclude(TopLevelExtensionsExclude) // completed via indices
             }
 
             filter

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

@@ -27,7 +27,10 @@ import com.intellij.patterns.StandardPatterns
 import com.intellij.psi.search.GlobalSearchScope
 import com.intellij.util.ProcessingContext
 import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.idea.caches.resolve.*
+import org.jetbrains.kotlin.idea.caches.resolve.ModuleOrigin
+import org.jetbrains.kotlin.idea.caches.resolve.OriginCapability
+import org.jetbrains.kotlin.idea.caches.resolve.getResolutionFacade
+import org.jetbrains.kotlin.idea.caches.resolve.getResolveScope
 import org.jetbrains.kotlin.idea.codeInsight.ReferenceVariantsHelper
 import org.jetbrains.kotlin.idea.core.*
 import org.jetbrains.kotlin.idea.imports.importableFqName
@@ -36,7 +39,6 @@ import org.jetbrains.kotlin.idea.references.mainReference
 import org.jetbrains.kotlin.idea.util.*
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
-import org.jetbrains.kotlin.psi.psiUtil.isExtensionDeclaration
 import org.jetbrains.kotlin.psi.psiUtil.parentsWithSelf
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
@@ -160,18 +162,11 @@ abstract class CompletionSession(
                                    declarationTranslator = { toFromOriginalFileMapper.toSyntheticFile(it) })
     }
 
-    // excludes top-level extensions except for ones declared in the current file - those that are fetched from indices
-    protected val topLevelExtensionsExclude = object : DescriptorKindExclude() {
-        val extensionsFromThisFile = file.declarations
-                .filter { it.isExtensionDeclaration() }
-                .map { it.resolveToDescriptor() }
-                .toSet()
-
+    protected object TopLevelExtensionsExclude : DescriptorKindExclude() {
         override fun excludes(descriptor: DeclarationDescriptor): Boolean {
             if (descriptor !is CallableMemberDescriptor) return false
             if (descriptor.extensionReceiverParameter == null) return false
-            if (descriptor in extensionsFromThisFile) return false
-            if (descriptor.kind != CallableMemberDescriptor.Kind.DECLARATION) return false /* do not filter out synthetic extensions from packages */
+            if (descriptor.kind != CallableMemberDescriptor.Kind.DECLARATION) return false /* do not filter out synthetic extensions */
             val containingPackage = descriptor.containingDeclaration as? PackageFragmentDescriptor ?: return false
             if (containingPackage.fqName.asString().startsWith("kotlinx.android.synthetic.")) return false // TODO: temporary solution for Android synthetic extensions
             return true

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/smart/SmartCompletionSession.kt

@@ -47,7 +47,7 @@ class SmartCompletionSession(
         // we do not include SAM-constructors because they are handled separately and adding them requires iterating of java classes
         var filter = DescriptorKindFilter.VALUES exclude SamConstructorDescriptorKindExclude
 
-        filter = filter exclude topLevelExtensionsExclude // handled via indices
+        filter = filter exclude TopLevelExtensionsExclude // handled via indices
 
         if (smartCompletion?.expectedInfos?.filterFunctionExpected()?.isNotEmpty() ?: false) {
             // if function type is expected we need classes to obtain their constructors