support full unwrap of RackLogger implementation

Author: kares

src/main/java/org/jruby/rack/RackLogger.java

@@ -47,4 +47,8 @@ public void setLevel(Level level) { /* noop */ }
         public boolean isFormatting() { return false; }
         public void setFormatting(boolean flag) { /* noop */ }
     }
+
+    interface DelegatingLogger extends RackLogger {
+        RackLogger unwrapLogger();
+    }
 }

src/main/java/org/jruby/rack/ext/Logger.java

@@ -123,6 +123,10 @@ public IRubyObject initialize_copy(final ThreadContext context, final IRubyObjec
 
     @JRubyMethod
     public IRubyObject real_logger(final ThreadContext context) {
+        RackLogger logger = this.logger;
+        if (logger instanceof RackLogger.DelegatingLogger) {
+            logger = ((RackLogger.DelegatingLogger) logger).unwrapLogger();
+        }
         return JavaEmbedUtils.javaToRuby(context.runtime, logger);
     }
 
@@ -357,8 +361,7 @@ public IRubyObject add(final ThreadContext context, final IRubyObject severity,
         return context.runtime.newBoolean( add(UNKNOWN, context, msg, block) );
     }
 
-    private boolean add(final int severity, final ThreadContext context,
-        IRubyObject msg, final Block block) {
+    private boolean add(final int severity, final ThreadContext context, IRubyObject msg, final Block block) {
         // severity ||= UNKNOWN
         final RackLogger.Level loggerLevel = mapLevel(severity);
 
@@ -455,7 +458,7 @@ private static int toInt(final IRubyObject level) {
     @SuppressWarnings("unchecked")
     @Override
     public <T> T toJava(Class<T> target) {
-        if ( RackLogger.class == target ) return (T) logger;
+        if ( RackLogger.class.isAssignableFrom(target) && target.isInstance(logger) ) return (T) logger;
         return super.toJava(target);
     }
 

src/main/java/org/jruby/rack/servlet/DefaultServletRackContext.java

@@ -35,7 +35,7 @@
  *
  * @author nicksieger
  */
-public class DefaultServletRackContext implements ServletRackContext {
+public class DefaultServletRackContext implements ServletRackContext, RackLogger.DelegatingLogger {
 
     private final RackConfig config;
     private final ServletContext context;
@@ -232,6 +232,11 @@ public void log(Level level, CharSequence message, Throwable e) {
         logger.log(level, message, e);
     }
 
+    @Override
+    public RackLogger unwrapLogger() {
+        return logger;
+    }
+
     @Override
     public int getEffectiveMajorVersion() throws UnsupportedOperationException {
         return context.getEffectiveMajorVersion();

src/spec/ruby/jruby/rack/logger_spec.rb

@@ -54,7 +54,7 @@
     logger = JRuby::Rack::Logger.new
     logger.debug?
     logger.debug 'hogy basza meg a zold tucsok!'
-    expect( logger.real_logger ).to be rack_context
+    expect( logger.to_java(org.jruby.rack.RackLogger) ).to be rack_context
   end
 
   it 'delegates level check (when level is not set)' do