From aace4bbfe3d2942644014319f9ea291f512e9a73 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Standa=20Luke=C5=A1?= <exyi@outlook.cz>
Date: Tue, 22 Mar 2022 14:59:48 +0000
Subject: [PATCH] Fix VirtualPropertyGroupDictionary.Clear

It was removing properties while it was iterating through
the dictionary :|
---
 .../Binding/VirtualPropertyGroupDictionary.cs | 20 ++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/Framework/Framework/Binding/VirtualPropertyGroupDictionary.cs b/src/Framework/Framework/Binding/VirtualPropertyGroupDictionary.cs
index c4d72f73aa..ca121e8bdd 100644
--- a/src/Framework/Framework/Binding/VirtualPropertyGroupDictionary.cs
+++ b/src/Framework/Framework/Binding/VirtualPropertyGroupDictionary.cs
@@ -246,14 +246,32 @@ public void Add(KeyValuePair<string, TValue> item)
 
         public void Clear()
         {
+            // we want to avoid allocating the list if there is only one property
+            DotvvmProperty? toRemove = null;
+            List<DotvvmProperty>? toRemoveRest = null;
+
             foreach (var (p, _) in control.properties)
             {
                 var pg = p as GroupedDotvvmProperty;
                 if (pg != null && pg.PropertyGroup == group)
                 {
-                    control.Properties.Remove(p);
+                    if (toRemove is null)
+                        toRemove = p;
+                    else
+                    {
+                        if (toRemoveRest is null)
+                            toRemoveRest = new List<DotvvmProperty>();
+                        toRemoveRest.Add(p);
+                    }
                 }
             }
+
+            if (toRemove is {})
+                control.Properties.Remove(toRemove);
+
+            if (toRemoveRest is {})
+                foreach (var p in toRemoveRest)
+                    control.Properties.Remove(p);
         }
 
         public bool Contains(KeyValuePair<string, TValue> item)