Handle nullable case in '==' with smart cast using safe call

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/OperatorExpressionGenerator.kt

@@ -30,7 +30,9 @@ import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.startOffset
+import org.jetbrains.kotlin.psi2ir.containsNull
 import org.jetbrains.kotlin.psi2ir.findSingleFunction
+import org.jetbrains.kotlin.psi2ir.intermediate.safeCallOnDispatchReceiver
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
 import org.jetbrains.kotlin.resolve.checkers.PrimitiveNumericComparisonInfo
@@ -277,6 +279,15 @@ class OperatorExpressionGenerator(statementGenerator: StatementGenerator) : Stat
             operandType == targetType || operandNNType == targetType ->
                 this
 
+            type.containsNull() ->
+                safeCallOnDispatchReceiver(this@OperatorExpressionGenerator, startOffset, endOffset) { dispatchReceiver ->
+                    invokeConversionFunction(
+                        startOffset, endOffset,
+                        conversionFunction ?: throw AssertionError("No conversion function for $type ~> $targetType"),
+                        dispatchReceiver
+                    )
+                }
+
             else ->
                 invokeConversionFunction(
                     startOffset, endOffset,

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/intermediate/SafeCallReceiver.kt

@@ -67,4 +67,20 @@ class SafeCallReceiver(
 
         return irBlock
     }
-}
+}
+
+
+fun IrExpression.safeCallOnDispatchReceiver(
+    generator: GeneratorWithScope,
+    startOffset: Int,
+    endOffset: Int,
+    ifNotNull: (IrExpression) -> IrExpression
+) =
+    SafeCallReceiver(
+        generator, startOffset, endOffset,
+        extensionReceiver = null,
+        dispatchReceiver = OnceExpressionValue(this),
+        isAssignmentReceiver = false
+    ).call { dispatchReceiverValue, _ ->
+        ifNotNull(dispatchReceiverValue!!.load())
+    }