Checking for conflicting substitutors in completion after "by"

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

@@ -184,3 +184,18 @@ class FuzzyType(
         return TypeSubstitutor.create(TypeConstructorSubstitution.createByConstructorsMap(substitution))
     }
 }
+
+
+fun TypeSubstitution.hasConflictWith(other: TypeSubstitution, freeParameters: Collection<TypeParameterDescriptor>): Boolean {
+    return freeParameters.any { parameter ->
+        val type = parameter.defaultType
+        val substituted1 = this[type] ?: return@any false
+        val substituted2 = other[type] ?: return@any false
+        !KotlinTypeChecker.FLEXIBLE_UNEQUAL_TO_INFLEXIBLE.equalTypes(substituted1.type, substituted2.type) || substituted1.projectionKind != substituted2.projectionKind
+    }
+}
+
+fun TypeSubstitutor.combineIfNoConflicts(other: TypeSubstitutor, freeParameters: Collection<TypeParameterDescriptor>): TypeSubstitutor? {
+    if (this.substitution.hasConflictWith(other.substitution, freeParameters)) return null
+    return TypeSubstitutor.createChainedSubstitutor(this.substitution, other.substitution)
+}

idea/idea-completion/testData/smart/propertyDelegate/ConflictingSubstitutors.kt

@@ -0,0 +1,11 @@
+import kotlin.reflect.KProperty
+
+class X<T> {
+    operator fun getValue(thisRef: T, property: KProperty<*>): T = throw Exception()
+}
+
+class C<T> {
+    val property: Int by <caret>
+}
+
+// ABSENT: X

idea/idea-completion/testData/smart/propertyDelegate/NonConflictingSubstitutors.kt

@@ -0,0 +1,11 @@
+import kotlin.reflect.KProperty
+
+class X<T>(t: T) {
+    operator fun getValue(thisRef: T, property: KProperty<*>): T = throw Exception()
+}
+
+class C<T> {
+    val property: C<T> by <caret>
+}
+
+// EXIST: { itemText: "X", tailText: "(t: C<T>) (<root>)" }

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

@@ -1450,6 +1450,12 @@ public class JvmSmartCompletionTestGenerated extends AbstractJvmSmartCompletionT
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/idea-completion/testData/smart/propertyDelegate"), Pattern.compile("^(.+)\\.kt$"), true);
         }
 
+        @TestMetadata("ConflictingSubstitutors.kt")
+        public void testConflictingSubstitutors() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/smart/propertyDelegate/ConflictingSubstitutors.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("DelegatesDot.kt")
         public void testDelegatesDot() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/smart/propertyDelegate/DelegatesDot.kt");
@@ -1522,6 +1528,12 @@ public class JvmSmartCompletionTestGenerated extends AbstractJvmSmartCompletionT
             doTest(fileName);
         }
 
+        @TestMetadata("NonConflictingSubstitutors.kt")
+        public void testNonConflictingSubstitutors() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/smart/propertyDelegate/NonConflictingSubstitutors.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("Order.kt")
         public void testOrder() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/idea-completion/testData/smart/propertyDelegate/Order.kt");

idea/idea-core/src/org/jetbrains/kotlin/idea/core/ExpectedInfos.kt

@@ -22,10 +22,7 @@ import org.jetbrains.kotlin.builtins.isFunctionType
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.idea.resolve.ResolutionFacade
 import org.jetbrains.kotlin.idea.resolve.ideService
-import org.jetbrains.kotlin.idea.util.FuzzyType
-import org.jetbrains.kotlin.idea.util.fuzzyExtensionReceiverType
-import org.jetbrains.kotlin.idea.util.fuzzyReturnType
-import org.jetbrains.kotlin.idea.util.getResolutionScope
+import org.jetbrains.kotlin.idea.util.*
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
@@ -632,9 +629,9 @@ class ExpectedInfos(
                 val propertyType = explicitPropertyType ?: getValueOperator.fuzzyReturnType()!!
                 val setParamType = FuzzyType(setValueOperator.valueParameters.last().type, setValueOperator.typeParameters)
                 val setParamTypeSubstitutor = setParamType.checkIsSuperTypeOf(propertyType) ?: return null
-                return TypeSubstitutor.createChainedSubstitutor(getOperatorSubstitutor.substitution,
-                                                                TypeSubstitutor.createChainedSubstitutor(setOperatorSubstitutor.substitution,
-                                                                                                         setParamTypeSubstitutor.substitution).substitution)
+                return getOperatorSubstitutor
+                        .combineIfNoConflicts(setOperatorSubstitutor, descriptorType.freeParameters)
+                        ?.combineIfNoConflicts(setParamTypeSubstitutor, descriptorType.freeParameters)
             }
 
             override val multipleFuzzyTypes: Collection<FuzzyType> by lazy {

idea/idea-core/src/org/jetbrains/kotlin/idea/core/TypesWithOperatorDetector.kt

@@ -20,6 +20,7 @@ import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
 import org.jetbrains.kotlin.idea.util.FuzzyType
+import org.jetbrains.kotlin.idea.util.combineIfNoConflicts
 import org.jetbrains.kotlin.idea.util.fuzzyExtensionReceiverType
 import org.jetbrains.kotlin.idea.util.nullability
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
@@ -138,7 +139,7 @@ class TypesWithGetValueDetector(
 
         val fuzzyReturnType = FuzzyType(operator.returnType ?: return null, freeTypeParams)
         val substitutorFromPropertyType = fuzzyReturnType.checkIsSubtypeOf(propertyType) ?: return null
-        return TypeSubstitutor.createChainedSubstitutor(substitutor.substitution, substitutorFromPropertyType.substitution)
+        return substitutor.combineIfNoConflicts(substitutorFromPropertyType, freeTypeParams)
     }
 }