From c98dba6aead64aab2ab560249e7807a252617f88 Mon Sep 17 00:00:00 2001
From: Vladimir Dolzhenko <vladimir.dolzhenko@jetbrains.com>
Date: Mon, 10 May 2021 09:59:16 +0200
Subject: [PATCH] Do not set diagnostics callback if it is already set

Relates to #KT-37702
---
 .../diagnostics/MutableDiagnosticsWithSuppression.kt       | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/diagnostics/MutableDiagnosticsWithSuppression.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/diagnostics/MutableDiagnosticsWithSuppression.kt
index c224d90d9cb..91b96df2a0f 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/diagnostics/MutableDiagnosticsWithSuppression.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/diagnostics/MutableDiagnosticsWithSuppression.kt
@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.resolve.diagnostics
 
+import com.intellij.openapi.diagnostic.Logger
 import com.intellij.openapi.util.CompositeModificationTracker
 import com.intellij.psi.PsiElement
 import com.intellij.psi.util.CachedValueProvider
@@ -48,8 +49,10 @@ class MutableDiagnosticsWithSuppression(
     override fun noSuppression() = readonlyView().noSuppression()
 
     override fun setCallback(callback: DiagnosticSink.DiagnosticsCallback) {
-        // TODO: [VD] temporary dirty patch, proper investigation is required
-        // assert(diagnosticsCallback == null) { "diagnostic callback has been already registered" }
+        diagnosticsCallback?.let {
+            Logger.getInstance(MutableDiagnosticsWithSuppression::class.java).error("diagnostic callback has been already registered")
+            return
+        }
         diagnosticsCallback = callback
         delegateDiagnostics.setCallback(callback)
     }