KT-30996: Use the last receiver to complete dsl methods

- change `detectReceiverTypes` return type to `List` instead of `Collection`
  - it reflects that receiver types are actually ordered
  - did not propagate signature changes to all possible places because it creates too much noise in git history
- ^KT-30996 Fixed

idea/ide-common/src/org/jetbrains/kotlin/idea/util/CallType.kt

@@ -249,7 +249,7 @@ fun CallTypeAndReceiver<*, *>.receiverTypes(
     moduleDescriptor: ModuleDescriptor,
     resolutionFacade: ResolutionFacade,
     stableSmartCastsOnly: Boolean
-): Collection<KotlinType>? {
+): List<KotlinType>? {
     return receiverTypesWithIndex(bindingContext, contextElement, moduleDescriptor, resolutionFacade, stableSmartCastsOnly)?.map { it.type }
 }
 
@@ -260,7 +260,7 @@ fun CallTypeAndReceiver<*, *>.receiverTypesWithIndex(
     resolutionFacade: ResolutionFacade,
     stableSmartCastsOnly: Boolean,
     withImplicitReceiversWhenExplicitPresent: Boolean = false
-): Collection<ReceiverType>? {
+): List<ReceiverType>? {
     val languageVersionSettings = resolutionFacade.frontendService<LanguageVersionSettings>()
 
     val receiverExpression: KtExpression?

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

@@ -417,7 +417,7 @@ abstract class CompletionSession(
         bindingContext: BindingContext,
         nameExpression: KtSimpleNameExpression,
         callTypeAndReceiver: CallTypeAndReceiver<*, *>
-    ): Collection<ReceiverType>? {
+    ): List<ReceiverType>? {
         var receiverTypes = callTypeAndReceiver.receiverTypesWithIndex(
             bindingContext, nameExpression, moduleDescriptor, resolutionFacade,
             stableSmartCastsOnly = true, /* we don't include smart cast receiver types for "unstable" receiver value to mark members grayed */

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

@@ -11,17 +11,23 @@ import org.jetbrains.kotlin.idea.util.CallTypeAndReceiver
 import org.jetbrains.kotlin.idea.util.ReceiverType
 import org.jetbrains.kotlin.psi.KtModifierListOwner
 import org.jetbrains.kotlin.psi.psiUtil.collectAnnotationEntriesFromStubOrPsi
-import org.jetbrains.kotlin.resolve.calls.DslMarkerUtils
 
 class DslMembersCompletion(
     private val prefixMatcher: PrefixMatcher,
     private val elementFactory: LookupElementFactory,
-    receiverTypes: Collection<ReceiverType>?,
+    receiverTypes: List<ReceiverType>?,
     private val collector: LookupElementsCollector,
     private val indicesHelper: KotlinIndicesHelper,
     private val callTypeAndReceiver: CallTypeAndReceiver<*, *>
 ) {
-    private val nearestReceiver = receiverTypes?.firstOrNull()
+    /**
+     * It is stated that `two implicit receivers of the same DSL are not accessible in the same scope`,
+     * that's why we need only the last one of the receivers to provide the completion (see [DslMarker]).
+     *
+     * When the last receiver is not a part of DSL, [nearestReceiverMarkers] will be empty, and dsl
+     * members would not be suggested in the autocompletion (see KT-30996).
+     */
+    private val nearestReceiver = receiverTypes?.lastOrNull()
     private val nearestReceiverMarkers = nearestReceiver?.takeIf { it.implicit }?.extractDslMarkers().orEmpty()
 
     fun completeDslFunctions() {

idea/idea-completion/testData/basic/common/dslMarker/noDslCompletionForNonDslReciever.kt

@@ -0,0 +1,15 @@
+@DslMarker
+annotation class MyDSL
+
+@MyDSL
+class HTML
+
+@MyDSL
+fun HTML.foo() { }
+
+fun HTML.test() {
+    val x = 1
+    x.<caret>
+}
+
+// ABSENT: foo

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

@@ -1175,6 +1175,11 @@ public class JSBasicCompletionTestGenerated extends AbstractJSBasicCompletionTes
                 runTest("idea/idea-completion/testData/basic/common/dslMarker/container.kt");
             }
 
+            @TestMetadata("noDslCompletionForNonDslReciever.kt")
+            public void testNoDslCompletionForNonDslReciever() throws Exception {
+                runTest("idea/idea-completion/testData/basic/common/dslMarker/noDslCompletionForNonDslReciever.kt");
+            }
+
             @TestMetadata("root.kt")
             public void testRoot() throws Exception {
                 runTest("idea/idea-completion/testData/basic/common/dslMarker/root.kt");

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

@@ -1175,6 +1175,11 @@ public class JvmBasicCompletionTestGenerated extends AbstractJvmBasicCompletionT
                 runTest("idea/idea-completion/testData/basic/common/dslMarker/container.kt");
             }
 
+            @TestMetadata("noDslCompletionForNonDslReciever.kt")
+            public void testNoDslCompletionForNonDslReciever() throws Exception {
+                runTest("idea/idea-completion/testData/basic/common/dslMarker/noDslCompletionForNonDslReciever.kt");
+            }
+
             @TestMetadata("root.kt")
             public void testRoot() throws Exception {
                 runTest("idea/idea-completion/testData/basic/common/dslMarker/root.kt");