[LOG4NET-614] If LogicalThreadContext has a property with NULL value it causes an exception

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 2.0.8
• Fix Version/s: 2.1.0
• Assignee: Dominik Psenner
• Reporter: Ilya Badaev
• Created: 18/Oct/18 10:51
• Updated: 22/Oct/18 18:23
• Resolved: 22/Oct/18 18:23

Description

I used to have the following inside the code:

log4net.LogicalThreadContext.Properties["EventID"] = (int)idEvent;
log.WarnFormat(format, p);
log4net.LogicalThreadContext.Properties["EventID"] = null;

It causes an exception in ReadOnlyPropertiesDictionary.GetObjectData(..)

in the following code:

                    // If value is serializable then we add it to the list
#if NETSTANDARD1_3
                bool isSerializable = entryValue.GetType().GetTypeInfo().IsSerializable;
#else
                    bool isSerializable = entryValue.GetType().IsSerializable;
#endif
                    if (entryKey != null && entryValue != null && isSerializable)
                    {
                        // Store the keys as an Xml encoded local name as it may contain colons (':') 
                        // which are NOT escaped by the Xml Serialization framework.
                        // This must be a bug in the serialization framework as we cannot be expected
                        // to know the implementation details of all the possible transport layers.
                        info.AddValue(XmlConvert.EncodeLocalName(entryKey), entryValue);
                    }
                }

The source of the problem is clear : the check for entryValue != null should be done before isSerializable is initiated.

 

As a workaround I changed my original code to be the following:

log4net.LogicalThreadContext.Properties["EventID"] = (int)idEvent;
log.WarnFormat(format, p);
log4net.LogicalThreadContext.Properties.Remove("EventID");

Issue Links

• duplicates: LOG4NET-581 NullReferenceException from log4net.Util.ReadOnlyPropertiesDictionary.GetObjectData