From 11b9ce4b9ccd6c30e1a38b8dd4867f2dcc0ecb6d Mon Sep 17 00:00:00 2001
From: mpv <mpv@opencascade.com>
Date: Mon, 8 Apr 2019 15:01:23 +0300
Subject: [PATCH] Fix for the issue #2900 : Crash or freeze when activating the
 Partset

---
 src/Model/Model_AttributeSelection.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/Model/Model_AttributeSelection.cpp b/src/Model/Model_AttributeSelection.cpp
index e540e3e66..3d325a688 100644
--- a/src/Model/Model_AttributeSelection.cpp
+++ b/src/Model/Model_AttributeSelection.cpp
@@ -1443,7 +1443,12 @@ void Model_AttributeSelection::updateInHistory(bool& theRemove)
               continue;
 
             FeaturePtr aRefFeat = std::dynamic_pointer_cast<ModelAPI_Feature>((*aRef)->owner());
+
             if (aRefFeat.get() && aRefFeat != owner() && aRefFeat->firstResult().get()) {
+              // check the reference is concealed: #2900
+              ModelAPI_ValidatorsFactory* aValidators = ModelAPI_Session::get()->validators();
+              if (!aValidators->isConcealed(aRefFeat->getKind(), (*aRef)->id()))
+                continue;
               FeaturePtr aThisFeature = std::dynamic_pointer_cast<ModelAPI_Feature>(owner());
               if (!aDoc->isLaterByDep(aRefFeat, aThisFeature)) { // found better feature
                 aFoundNewContext = true;
-- 
2.39.2