Only render custom icons if they are applied

Author: madskristensen

src/toolkit/Community.VisualStudio.Toolkit.Shared/ErrorList/TableEntriesSnapshot.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using Microsoft.VisualStudio.Shell.TableManager;
 
@@ -39,6 +40,15 @@ public override bool TryGetValue(int index, string columnName, out object? conte
                 return false;
             }
 
+            if (columnName == StandardTableKeyNames.PriorityImage || columnName == StandardTableKeyNames.ErrorSeverityImage)
+            {
+                if (_errors[index].Icon.Guid == Guid.Empty)
+                {
+                    content = _errors[index].Icon;
+                    return true;
+                }
+            }
+
             switch (columnName)
             {
                 case StandardTableKeyNames.ProjectName:
@@ -85,11 +95,6 @@ public override bool TryGetValue(int index, string columnName, out object? conte
                     content = _errors[index].ErrorCodeToolTip;
                     break;
 
-                case StandardTableKeyNames.PriorityImage:
-                case StandardTableKeyNames.ErrorSeverityImage:
-                    content = _errors[index].Icon;
-                    break;
-
                 default:
                     content = null;
                     return false;