#281 fix hints and warnings

src/log4net/Appender/AdoNetAppender.cs

@@ -44,8 +44,8 @@ namespace log4net.Appender;
 /// <para>
 /// Records are written into the database either using a prepared
 /// statement or a stored procedure. The <see cref="CommandType"/> property
-/// is set to <see cref="System.Data.CommandType.Text"/> (<c>System.Data.CommandType.Text</c>) to specify a prepared statement
-/// or to <see cref="System.Data.CommandType.StoredProcedure"/> (<c>System.Data.CommandType.StoredProcedure</c>) to specify a stored
+/// is set to <see cref="CommandType.Text"/> (<c>System.Data.CommandType.Text</c>) to specify a prepared statement
+/// or to <see cref="CommandType.StoredProcedure"/> (<c>System.Data.CommandType.StoredProcedure</c>) to specify a stored
 /// procedure.
 /// </para>
 /// <para>
@@ -254,14 +254,14 @@ public AdoNetAppender()
   /// </value>
   /// <remarks>
   /// <para>
-  /// This value may be either <see cref="System.Data.CommandType.Text"/> (<c>System.Data.CommandType.Text</c>) to specify
+  /// This value may be either <see cref="CommandType.Text"/> (<c>System.Data.CommandType.Text</c>) to specify
   /// that the <see cref="CommandText"/> is a prepared statement to execute, 
-  /// or <see cref="System.Data.CommandType.StoredProcedure"/> (<c>System.Data.CommandType.StoredProcedure</c>) to specify that the
+  /// or <see cref="CommandType.StoredProcedure"/> (<c>System.Data.CommandType.StoredProcedure</c>) to specify that the
   /// <see cref="CommandText"/> property is the name of a stored procedure
   /// to execute.
   /// </para>
   /// <para>
-  /// The default value is <see cref="System.Data.CommandType.Text"/> (<c>System.Data.CommandType.Text</c>).
+  /// The default value is <see cref="CommandType.Text"/> (<c>System.Data.CommandType.Text</c>).
   /// </para>
   /// </remarks>
   public CommandType CommandType { get; set; }
@@ -270,8 +270,8 @@ public AdoNetAppender()
   /// Should transactions be used to insert logging events in the database.
   /// </summary>
   /// <value>
-  /// <c>true</c> if transactions should be used to insert logging events in
-  /// the database, otherwise <c>false</c>. The default value is <c>true</c>.
+  /// <see langword="true"/> if transactions should be used to insert logging events in
+  /// the database, otherwise <see langword="false"/>. The default value is <see langword="true"/>.
   /// </value>
   /// <remarks>
   /// <para>
@@ -306,8 +306,8 @@ public AdoNetAppender()
   /// Should this appender try to reconnect to the database on error.
   /// </summary>
   /// <value>
-  /// <c>true</c> if the appender should try to reconnect to the database after an
-  /// error has occurred, otherwise <c>false</c>. The default value is <c>false</c>, 
+  /// <see langword="true"/> if the appender should try to reconnect to the database after an
+  /// error has occurred, otherwise <see langword="false"/>. The default value is <see langword="false"/>, 
   /// i.e. not to try to reconnect.
   /// </value>
   /// <remarks>
@@ -317,7 +317,7 @@ public AdoNetAppender()
   /// </para>
   /// <para>
   /// To force the appender to attempt to reconnect to the database set this
-  /// property to <c>true</c>.
+  /// property to <see langword="true"/>.
   /// </para>
   /// <note>
   /// When the appender attempts to connect to the database there may be a
@@ -458,7 +458,7 @@ protected override void SendBuffer(LoggingEvent[] events)
   /// <param name="events">The array of events to insert into the database.</param>
   /// <remarks>
   /// <para>
-  /// The transaction argument can be <c>null</c> if the appender has been
+  /// The transaction argument can be <see langword="null"/> if the appender has been
   /// configured not to use transactions. See <see cref="UseTransactions"/>
   /// property for more information.
   /// </para>
@@ -550,7 +550,7 @@ protected virtual void Prepare(IDbCommand dbCmd)
   /// more control over the format of the database statement.
   /// </remarks>
   /// <returns>
-  /// Text that can be passed to a <see cref="System.Data.IDbCommand"/>.
+  /// Text that can be passed to a <see cref="IDbCommand"/>.
   /// </returns>
   protected virtual string GetLogStatement(LoggingEvent logEvent)
   {
@@ -742,7 +742,7 @@ private void DisposeConnection()
 /// <remarks>
 /// <para>
 /// This class provides the basic database parameter properties
-/// as defined by the <see cref="System.Data.IDbDataParameter"/> interface.
+/// as defined by the <see cref="IDbDataParameter"/> interface.
 /// </para>
 /// <para>This type can be subclassed to provide database specific
 /// functionality. The two methods that are called externally are

src/log4net/Appender/AppenderSkeleton.cs

@@ -59,7 +59,7 @@ public abstract class AppenderSkeleton : IAppender, IBulkAppender, IOptionHandle
   /// </summary>
   /// <remarks>
   /// <para>
-  /// If this appender has not been closed then the <c>Finalize</c> method
+  /// If this appender has not been closed then the <see cref="Finalize"/> method
   /// will call <see cref="Close"/>.
   /// </para>
   /// </remarks>
@@ -236,7 +236,7 @@ public void Close()
   ///    <item>
   ///      <description>
   ///      Calls <see cref="PreAppendCheck()"/> and checks that 
-  ///      it returns <c>true</c>.</description>
+  ///      it returns <see langword="true"/>.</description>
   ///    </item>
   /// </list>
   /// </para>
@@ -318,7 +318,7 @@ public void DoAppend(LoggingEvent loggingEvent)
   ///    <item>
   ///      <description>
   ///      Calls <see cref="PreAppendCheck()"/> and checks that 
-  ///      it returns <c>true</c>.</description>
+  ///      it returns <see langword="true"/>.</description>
   ///    </item>
   /// </list>
   /// </para>
@@ -383,7 +383,7 @@ public void DoAppend(LoggingEvent[] loggingEvents)
   /// Test if the logging event should we output by this appender
   /// </summary>
   /// <param name="loggingEvent">the event to test</param>
-  /// <returns><c>true</c> if the event should be output, <c>false</c> if the event should be ignored</returns>
+  /// <returns><see langword="true"/> if the event should be output, <see langword="false"/> if the event should be ignored</returns>
   /// <remarks>
   /// <para>
   /// This method checks the logging event against the threshold level set
@@ -482,8 +482,8 @@ public virtual void AddFilter(IFilter filter)
   /// </summary>
   /// <param name="level"><see cref="Level"/> to test against.</param>
   /// <returns>
-  /// <c>true</c> if the <paramref name="level"/> meets the <see cref="Threshold"/> 
-  /// requirements of this appender. A null level always maps to <c>true</c>,
+  /// <see langword="true"/> if the <paramref name="level"/> meets the <see cref="Threshold"/> 
+  /// requirements of this appender. A null level always maps to <see langword="true"/>,
   /// the equivalent of <see cref="Level.All"/>.
   /// </returns>
   protected virtual bool IsAsSevereAsThreshold(Level? level) => level is null || level >= Threshold;
@@ -587,7 +587,7 @@ protected virtual void Append(IEnumerable<LoggingEvent> loggingEvents)
   /// this base class if it is overridden.
   /// </para>
   /// </remarks>
-  /// <returns><c>true</c> if the call to <see cref="Append(LoggingEvent)"/> should proceed.</returns>
+  /// <returns><see langword="true"/> if the call to <see cref="Append(LoggingEvent)"/> should proceed.</returns>
   protected virtual bool PreAppendCheck()
   {
     if ((Layout is null) && RequiresLayout)
@@ -698,14 +698,14 @@ protected void RenderLoggingEvent(TextWriter writer, LoggingEvent loggingEvent)
   /// <para>
   /// In the rather exceptional case, where the appender 
   /// implementation admits a layout but can also work without it, 
-  /// then the appender should return <c>true</c>.
+  /// then the appender should return <see langword="true"/>.
   /// </para>
   /// <para>
-  /// This default implementation always returns <c>false</c>.
+  /// This default implementation always returns <see langword="false"/>.
   /// </para>
   /// </remarks>
   /// <returns>
-  /// <c>true</c> if the appender requires a layout object, otherwise <c>false</c>.
+  /// <see langword="true"/> if the appender requires a layout object, otherwise <see langword="false"/>.
   /// </returns>
   protected virtual bool RequiresLayout => false;
 
@@ -715,7 +715,7 @@ protected void RenderLoggingEvent(TextWriter writer, LoggingEvent loggingEvent)
   /// <remarks>
   /// This implementation doesn't flush anything and always returns true
   /// </remarks>
-  /// <returns><c>True</c> if all logging events were flushed successfully, else <c>false</c>.</returns>
+  /// <returns><see langword="true"/> if all logging events were flushed successfully, else <see langword="false"/>.</returns>
   public virtual bool Flush(int millisecondsTimeout) => true;
 
   /// <summary>

src/log4net/Appender/BufferingAppenderSkeleton.cs

@@ -56,7 +56,7 @@ namespace log4net.Appender;
 /// The buffering appender can be configured in a <see cref="Lossy"/> mode. 
 /// By default the appender is NOT lossy. When the buffer is full all 
 /// the buffered events are sent with <see cref="SendBuffer(LoggingEvent[])"/>.
-/// If the <see cref="Lossy"/> property is set to <c>true</c> then the 
+/// If the <see cref="Lossy"/> property is set to <see langword="true"/> then the 
 /// buffer will not be sent when it is full, and new events arriving 
 /// in the appender will overwrite the oldest event in the buffer. 
 /// In lossy mode the buffer will only be sent when the <see cref="Evaluator"/>
@@ -87,7 +87,7 @@ protected BufferingAppenderSkeleton() : this(true)
   /// Initializes a new instance of the <see cref="BufferingAppenderSkeleton" /> class.
   /// </summary>
   /// <param name="eventMustBeFixed">the events passed through this appender must be
-  /// fixed by the time that they arrive in the derived class' <c>SendBuffer</c> method.</param>
+  /// fixed by the time that they arrive in the derived class' <see cref="SendBuffer"/> method.</param>
   /// <remarks>
   /// <para>
   /// Protected constructor to allow subclassing.
@@ -107,18 +107,18 @@ protected BufferingAppenderSkeleton(bool eventMustBeFixed)
   /// Gets or sets a value that indicates whether the appender is lossy.
   /// </summary>
   /// <value>
-  /// <c>true</c> if the appender is lossy, otherwise <c>false</c>. The default is <c>false</c>.
+  /// <see langword="true"/> if the appender is lossy, otherwise <see langword="false"/>. The default is <see langword="false"/>.
   /// </value>
   /// <remarks>
   /// <para>
   /// This appender uses a buffer to store logging events before 
   /// delivering them. A triggering event causes the whole buffer
   /// to be sent to the remote sink. If the buffer overruns before
   /// a triggering event then logging events could be lost. Set
-  /// <see cref="Lossy"/> to <c>false</c> to prevent logging events 
+  /// <see cref="Lossy"/> to <see langword="false"/> to prevent logging events 
   /// from being lost.
   /// </para>
-  /// <para>If <see cref="Lossy"/> is set to <c>true</c> then an
+  /// <para>If <see cref="Lossy"/> is set to <see langword="true"/> then an
   /// <see cref="Evaluator"/> must be specified.</para>
   /// </remarks>
   public bool Lossy { get; set; }
@@ -162,7 +162,7 @@ protected BufferingAppenderSkeleton(bool eventMustBeFixed)
   /// appender. If the evaluator triggers then the current buffer will 
   /// immediately be sent (see <see cref="SendBuffer(LoggingEvent[])"/>).
   /// </para>
-  /// <para>If <see cref="Lossy"/> is set to <c>true</c> then an
+  /// <para>If <see cref="Lossy"/> is set to <see langword="true"/> then an
   /// <see cref="Evaluator"/> must be specified.</para>
   /// </remarks>
   public ITriggeringEventEvaluator? Evaluator { get; set; }
@@ -202,7 +202,7 @@ protected BufferingAppenderSkeleton(bool eventMustBeFixed)
   /// Flushes any buffered log data.
   /// </summary>
   /// <param name="millisecondsTimeout">The maximum time to wait for logging events to be flushed.</param>
-  /// <returns><c>True</c> if all logging events were flushed successfully, else <c>false</c>.</returns>
+  /// <returns><see langword="true"/> if all logging events were flushed successfully, else <see langword="false"/>.</returns>
   public override bool Flush(int millisecondsTimeout)
   {
     Flush();
@@ -226,21 +226,21 @@ public override bool Flush(int millisecondsTimeout)
   /// <summary>
   /// Flush the currently buffered events
   /// </summary>
-  /// <param name="flushLossyBuffer">set to <c>true</c> to flush the buffer of lossy events</param>
+  /// <param name="flushLossyBuffer">set to <see langword="true"/> to flush the buffer of lossy events</param>
   /// <remarks>
   /// <para>
   /// Flushes events that have been buffered. If <paramref name="flushLossyBuffer" /> is
-  /// <c>false</c> then events will only be flushed if this buffer is non-lossy mode.
+  /// <see langword="false"/> then events will only be flushed if this buffer is non-lossy mode.
   /// </para>
   /// <para>
   /// If the appender is buffering in <see cref="Lossy"/> mode then the contents
-  /// of the buffer will only be flushed if <paramref name="flushLossyBuffer" /> is <c>true</c>.
+  /// of the buffer will only be flushed if <paramref name="flushLossyBuffer" /> is <see langword="true"/>.
   /// In this case the contents of the buffer will be tested against the 
   /// <see cref="LossyEvaluator"/> and if triggering will be output. All other buffered
   /// events will be discarded.
   /// </para>
   /// <para>
-  /// If <paramref name="flushLossyBuffer" /> is <c>true</c> then the buffer will always
+  /// If <paramref name="flushLossyBuffer" /> is <see langword="true"/> then the buffer will always
   /// be emptied by calling this method.
   /// </para>
   /// </remarks>
@@ -262,7 +262,7 @@ public virtual void Flush(bool flushLossyBuffer)
             {
               // Test the contents of the buffer against the lossy evaluator
               LoggingEvent[] bufferedEvents = _cyclicBuffer.PopAll();
-              var filteredEvents = new List<LoggingEvent>(bufferedEvents.Length);
+              List<LoggingEvent> filteredEvents = new(bufferedEvents.Length);
 
               foreach (LoggingEvent loggingEvent in bufferedEvents)
               {

src/log4net/Appender/BufferingForwardingAppender.cs

@@ -138,7 +138,7 @@ public virtual AppenderCollection Appenders
   /// </summary>
   /// <param name="name">The name of the appender to lookup.</param>
   /// <returns>
-  /// The appender with the specified name, or <c>null</c>.
+  /// The appender with the specified name, or <see langword="null"/>.
   /// </returns>
   public virtual IAppender? GetAppender(string? name)
   {

src/log4net/Appender/ColoredConsoleAppender.cs

@@ -181,7 +181,7 @@ public virtual string Target
   public void AddMapping(LevelColors mapping) => _levelMapping.Add(mapping);
 
   /// <summary>
-  /// This method is called by the <see cref="AppenderSkeleton.DoAppend(log4net.Core.LoggingEvent)"/> method.
+  /// This method is called by the <see cref="AppenderSkeleton.DoAppend(LoggingEvent)"/> method.
   /// </summary>
   /// <param name="loggingEvent">The event to log.</param>
   /// <remarks>

src/log4net/Appender/DebugAppender.cs

@@ -48,7 +48,7 @@ public class DebugAppender : AppenderSkeleton
   /// </summary>
   /// <remarks>
   /// <para>The default behavior is to flush at the end of each 
-  /// write. If the option is set to<c>false</c>, then the underlying 
+  /// write. If the option is set to<see langword="false"/>, then the underlying 
   /// stream can defer writing to physical medium to a later time. 
   /// </para>
   /// <para>
@@ -67,7 +67,7 @@ public class DebugAppender : AppenderSkeleton
   /// </summary>
   /// <remarks>
   /// <para>
-  /// Defaults to a <see cref="Layout.PatternLayout"/> with %logger as the pattern which will use the logger name of the current 
+  /// Defaults to a <see cref="PatternLayout"/> with %logger as the pattern which will use the logger name of the current 
   /// <see cref="LoggingEvent"/> as the category parameter.
   /// </para>
   /// </remarks>
@@ -77,7 +77,7 @@ public class DebugAppender : AppenderSkeleton
   /// Flushes any buffered log data.
   /// </summary>
   /// <param name="millisecondsTimeout">The maximum time to wait for logging events to be flushed.</param>
-  /// <returns><c>True</c> if all logging events were flushed successfully, else <c>false</c>.</returns>
+  /// <returns><see langword="true"/> if all logging events were flushed successfully, else <see langword="false"/>.</returns>
   public override bool Flush(int millisecondsTimeout)
   {
     // Nothing to do if ImmediateFlush is true
@@ -99,7 +99,7 @@ public override bool Flush(int millisecondsTimeout)
   /// <remarks>
   /// <para>
   /// Writes the logging event to the <see cref="System.Diagnostics.Debug"/> system.
-  /// If <see cref="ImmediateFlush"/> is <c>true</c> then the <see cref="System.Diagnostics.Debug.Flush"/>
+  /// If <see cref="ImmediateFlush"/> is <see langword="true"/> then the <see cref="System.Diagnostics.Debug.Flush"/>
   /// is called.
   /// </para>
   /// </remarks> 

src/log4net/Appender/EventLogAppender.cs

@@ -42,8 +42,8 @@ namespace log4net.Appender;
 /// on the <see cref="LoggingEvent"/>.
 /// </para>
 /// <para>
-/// The <c>Category</c> of the event log entry can be
-/// set using the <c>Category</c> property (<see cref="LoggingEvent.Properties"/>)
+/// The <see cref="Category"/> of the event log entry can be
+/// set using the <see cref="Category"/> property (<see cref="LoggingEvent.Properties"/>)
 /// on the <see cref="LoggingEvent"/>.
 /// </para>
 /// <para>
@@ -174,7 +174,7 @@ public EventLogAppender()
   public SecurityContext? SecurityContext { get; set; }
 
   /// <summary>
-  /// Gets or sets the <c>EventId</c> to use unless one is explicitly specified via the <c>LoggingEvent</c>'s properties.
+  /// Gets or sets the <see cref="EventId"/> to use unless one is explicitly specified via the <c>LoggingEvent</c>'s properties.
   /// </summary>
   /// <remarks>
   /// <para>
@@ -188,12 +188,12 @@ public EventLogAppender()
 
 
   /// <summary>
-  /// Gets or sets the <c>Category</c> to use unless one is explicitly specified via the <c>LoggingEvent</c>'s properties.
+  /// Gets or sets the <see cref="Category"/> to use unless one is explicitly specified via the <c>LoggingEvent</c>'s properties.
   /// </summary>
   /// <remarks>
   /// <para>
-  /// The <c>Category</c> of the event log entry will normally be
-  /// set using the <c>Category</c> property (<see cref="LoggingEvent.Properties"/>)
+  /// The <see cref="Category"/> of the event log entry will normally be
+  /// set using the <see cref="Category"/> property (<see cref="LoggingEvent.Properties"/>)
   /// on the <see cref="LoggingEvent"/>.
   /// This property provides the fallback value which defaults to 0.
   /// </para>
@@ -287,7 +287,7 @@ public override void ActivateOptions()
   /// </summary>
   private static void CreateEventSource(string source, string logName, string machineName)
   {
-    var eventSourceCreationData = new EventSourceCreationData(source, logName)
+    EventSourceCreationData eventSourceCreationData = new(source, logName)
     {
       MachineName = machineName
     };
@@ -402,7 +402,7 @@ protected override void Append(LoggingEvent loggingEvent)
   /// <summary>
   /// This appender requires a <see cref="Layout"/> to be set.
   /// </summary>
-  /// <value><c>true</c></value>
+  /// <value><see langword="true"/></value>
   protected override bool RequiresLayout => true;
 
   /// <summary>

src/log4net/Appender/ForwardingAppender.cs

@@ -128,7 +128,7 @@ public virtual AppenderCollection Appenders
   /// </summary>
   /// <param name="name">The name of the appender to lookup.</param>
   /// <returns>
-  /// The appender with the specified name, or <c>null</c>.
+  /// The appender with the specified name, or <see langword="null"/>.
   /// </returns>
   /// <remarks>
   /// <para>