Fix for issue 6768 NullRef when access Level when there are EventSource messages.

See https://github.com/dotnet/coreclr/issues/6768 for mor details on the bug.

The issue is that EventSource is firing events (to report errors) before the EventSource
is completely initialized.   We dealt with many of the issues associated with this but
not all of them.   This change makes these special eventSource events (with ID of 0
 take the same codepath as for TraceLogging events (with negative IDs) when the
EventWrittenArgs properies are accessed.

diff --git a/src/mscorlib/src/System/Diagnostics/Eventing/EventSource.cs b/src/mscorlib/src/System/Diagnostics/Eventing/EventSource.cs
index 8c2edfd..bb23323 100644 (file)
--- a/src/mscorlib/src/System/Diagnostics/Eventing/EventSource.cs
+++ b/src/mscorlib/src/System/Diagnostics/Eventing/EventSource.cs
@@ -4893,7 +4893,7 @@ namespace System.Diagnostics.Tracing
         {
             get
             {
-                if (EventId < 0)      // TraceLogging convention EventID == -1
+                if (EventId <= 0)      // TraceLogging convention EventID == -1
                     return m_opcode;
                 return (EventOpcode)m_eventSource.m_eventData[EventId].Descriptor.Opcode;
             }
@@ -4906,7 +4906,7 @@ namespace System.Diagnostics.Tracing
         {
             get
             {
-                if (EventId < 0)      // TraceLogging convention EventID == -1
+                if (EventId <= 0)      // TraceLogging convention EventID == -1
                     return EventTask.None;
 
                 return (EventTask)m_eventSource.m_eventData[EventId].Descriptor.Task;
@@ -4920,7 +4920,7 @@ namespace System.Diagnostics.Tracing
         {
             get
             {
-                if (EventId < 0)      // TraceLogging convention EventID == -1
+                if (EventId <= 0)      // TraceLogging convention EventID == -1
                     return m_tags;
                 return m_eventSource.m_eventData[EventId].Tags;
             }
@@ -4933,7 +4933,7 @@ namespace System.Diagnostics.Tracing
         {
             get
             {
-                if (EventId < 0)      // TraceLogging convention EventID == -1
+                if (EventId <= 0)      // TraceLogging convention EventID == -1
                     return m_message;
                 else
                     return m_eventSource.m_eventData[EventId].Message;
@@ -4953,7 +4953,7 @@ namespace System.Diagnostics.Tracing
         {
             get
             {
-                if (EventId < 0)      // TraceLogging convention EventID == -1
+                if (EventId <= 0)      // TraceLogging convention EventID == -1
                     return EventChannel.None;
                 return (EventChannel)m_eventSource.m_eventData[EventId].Descriptor.Channel;
             }
@@ -4967,7 +4967,7 @@ namespace System.Diagnostics.Tracing
         {
             get
             {
-                if (EventId < 0)      // TraceLogging convention EventID == -1
+                if (EventId <= 0)      // TraceLogging convention EventID == -1
                     return 0;
                 return m_eventSource.m_eventData[EventId].Descriptor.Version;
             }
@@ -4980,7 +4980,7 @@ namespace System.Diagnostics.Tracing
         {
             get
             {
-                if (EventId < 0)      // TraceLogging convention EventID == -1
+                if (EventId <= 0)      // TraceLogging convention EventID == -1
                     return m_level;
                 return (EventLevel)m_eventSource.m_eventData[EventId].Descriptor.Level;
             }