FIR IDE: do not complete after where constraint type param with qualifier

idea/idea-fir/src/org/jetbrains/kotlin/idea/completion/KotlinFirCompletionContributor.kt

@@ -111,6 +111,10 @@ private object KotlinFirCompletionProvider : CompletionProvider<CompletionParame
             is FirUnknownPositionContext -> {
                 complete(keywordContributor, positionContext)
             }
+
+            is FirIncorrectPositionContext -> {
+                // do nothing, completion is not suposed to be called here
+            }
         }
     }
 

idea/idea-fir/src/org/jetbrains/kotlin/idea/completion/context/FirPositionCompletionContext.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.idea.completion.context
 
 import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiErrorElement
 import com.intellij.psi.util.parentOfType
 import org.jetbrains.kotlin.idea.frontend.api.KtAnalysisSession
 import org.jetbrains.kotlin.idea.frontend.api.analyse
@@ -19,6 +20,10 @@ internal sealed class FirRawPositionCompletionContext {
     abstract val position: PsiElement
 }
 
+internal class FirIncorrectPositionContext(
+    override val position: PsiElement
+): FirRawPositionCompletionContext()
+
 internal class FirTypeConstraintNameInWhereClausePositionContext(
     override val position: PsiElement,
     val typeParametersOwner: KtTypeParameterListOwner
@@ -146,22 +151,26 @@ internal object FirPositionCompletionContextDetector {
         reference: KtSimpleNameReference,
         nameExpression: KtSimpleNameExpression,
         explicitReceiver: KtExpression?
-    ): FirNameReferencePositionContext {
+    ): FirRawPositionCompletionContext {
         val typeReference = (userType.parent as? KtTypeReference)?.takeIf { it.typeElement == userType }
-        return when (val typeReferenceOwner = typeReference?.parent) {
+        val typeReferenceOwner = typeReference?.parent
-            is KtConstructorCalleeExpression -> {
+        return when {
+            typeReferenceOwner is KtConstructorCalleeExpression -> {
                 val constructorCall = typeReferenceOwner.takeIf { it.typeReference == typeReference }
                 val annotationEntry = (constructorCall?.parent as? KtAnnotationEntry)?.takeIf { it.calleeExpression == constructorCall }
                 annotationEntry?.let {
                     FirAnnotationTypeNameReferencePositionContext(position, reference, nameExpression, explicitReceiver, it)
                 }
             }
-            is KtSuperExpression -> {
+            typeReferenceOwner is KtSuperExpression -> {
                 val superTypeCallEntry = typeReferenceOwner.takeIf { it.superTypeQualifier == typeReference }
                 superTypeCallEntry?.let {
                     FirSuperTypeCallNameReferencePositionContext(position, reference, nameExpression, explicitReceiver, it)
                 }
             }
+            typeReferenceOwner is KtTypeConstraint && typeReferenceOwner.children.any { it is PsiErrorElement } -> {
+                FirIncorrectPositionContext(position)
+            }
             else -> null
         } ?: FirTypeNameReferencePositionContext(position, reference, nameExpression, explicitReceiver)
     }
@@ -180,7 +189,8 @@ internal object FirPositionCompletionContextDetector {
             is FirUnknownPositionContext,
             is FirImportDirectivePositionContext,
             is FirPackageDirectivePositionContext,
-            is FirTypeConstraintNameInWhereClausePositionContext -> {
+            is FirTypeConstraintNameInWhereClausePositionContext,
+            is FirIncorrectPositionContext -> {
                 analyse(basicContext.originalKtFile, action)
             }
         }

idea/idea-fir/src/org/jetbrains/kotlin/idea/completion/contributors/FirKeywordCompletionContributor.kt

@@ -46,8 +46,8 @@ internal class FirKeywordCompletionContributor(basicContext: FirBasicCompletionC
                     else -> reference.expression
                 }
             }
-            is FirTypeConstraintNameInWhereClausePositionContext -> {
+            is FirTypeConstraintNameInWhereClausePositionContext, is FirIncorrectPositionContext -> {
-                error("keyword completion should not be called for FirTypeConstraintNameInWhereClausePositionContext")
+                error("keyword completion should not be called for ${positionContext::class.simpleName}")
             }
             is FirUnknownPositionContext -> null
         }