Inference for some kind of self types

compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/KotlinConstraintSystemCompleter.kt

@@ -293,17 +293,51 @@ class KotlinConstraintSystemCompleter(
 
             val variableWithConstraints = notFixedTypeVariables.getValue(variableForFixation.variable)
 
-            if (variableForFixation.hasProperConstraint) {
-                fixVariable(this, variableWithConstraints, topLevelAtoms)
-                return true
-            } else {
-                processVariableWhenNotEnoughInformation(this, variableWithConstraints, topLevelAtoms, diagnosticsHolder)
+            when {
+                variableForFixation.hasProperConstraint -> {
+                    fixVariable(this, variableWithConstraints, topLevelAtoms)
+                    return true
+                }
+
+                hasDeclaredUpperBoundSelfTypes(variableWithConstraints) -> {
+                    fixVariable(this, variableWithConstraints, topLevelAtoms)
+                    return true
+                }
+
+                else -> processVariableWhenNotEnoughInformation(this, variableWithConstraints, topLevelAtoms, diagnosticsHolder)
             }
         }
 
         return false
     }
 
+    private fun ConstraintSystemCompletionContext.hasDeclaredUpperBoundSelfTypes(variable: VariableWithConstraints): Boolean {
+        val constraints = variable.constraints
+        return constraints.isNotEmpty() && constraints.all {
+            it.position.from is DeclaredUpperBoundConstraintPosition<*> && isSelfType(it.type.typeConstructor())
+        }
+    }
+
+    private fun ConstraintSystemCompletionContext.isSelfType(typeConstructor: TypeConstructorMarker): Boolean {
+        if (typeConstructor.isTypeParameterTypeConstructor()) {
+            val supertype = typeConstructor.supertypes().firstOrNull() ?: return false
+            return isSelfType(supertype.typeConstructor())
+        }
+
+        val parametersCount = typeConstructor.parametersCount()
+        if (parametersCount == 0) return false
+
+        for (parameterId in 0 until parametersCount) {
+            val parameter = typeConstructor.getParameter(parameterId)
+            if (parameter.upperBoundCount() != 1) return false
+
+            val upperBound = parameter.getUpperBound(0)
+            if (upperBound.typeConstructor() == typeConstructor) return true
+        }
+
+        return false
+    }
+
     private fun processVariableWhenNotEnoughInformation(
         c: ConstraintSystemCompletionContext,
         variableWithConstraints: VariableWithConstraints,