[#5239] Allow adding handlers to pipeline with null name.

Motivation:

While doing 8fe3c83e4c I made a change which disallowed using null as name for handlers in the pipeline (this generated a new name before).

Modifications:

Revert to old behaviour and adding test case.

Result:

Allow null name again

transport/src/main/java/io/netty/channel/ChannelPipeline.java

@@ -225,7 +225,7 @@ public interface ChannelPipeline
      * @throws IllegalArgumentException
      *         if there's an entry with the same name already in the pipeline
      * @throws NullPointerException
-     *         if the specified name or handler is {@code null}
+     *         if the specified handler is {@code null}
      */
     ChannelPipeline addFirst(String name, ChannelHandler handler);
 
@@ -240,7 +240,7 @@ public interface ChannelPipeline
      * @throws IllegalArgumentException
      *         if there's an entry with the same name already in the pipeline
      * @throws NullPointerException
-     *         if the specified name or handler is {@code null}
+     *         if the specified handler is {@code null}
      */
     ChannelPipeline addFirst(EventExecutorGroup group, String name, ChannelHandler handler);
 
@@ -253,7 +253,7 @@ public interface ChannelPipeline
      * @throws IllegalArgumentException
      *         if there's an entry with the same name already in the pipeline
      * @throws NullPointerException
-     *         if the specified name or handler is {@code null}
+     *         if the specified handler is {@code null}
      */
     ChannelPipeline addLast(String name, ChannelHandler handler);
 
@@ -268,7 +268,7 @@ public interface ChannelPipeline
      * @throws IllegalArgumentException
      *         if there's an entry with the same name already in the pipeline
      * @throws NullPointerException
-     *         if the specified name or handler is {@code null}
+     *         if the specified handler is {@code null}
      */
     ChannelPipeline addLast(EventExecutorGroup group, String name, ChannelHandler handler);
 
@@ -285,7 +285,7 @@ public interface ChannelPipeline
      * @throws IllegalArgumentException
      *         if there's an entry with the same name already in the pipeline
      * @throws NullPointerException
-     *         if the specified baseName, name, or handler is {@code null}
+     *         if the specified baseName or handler is {@code null}
      */
     ChannelPipeline addBefore(String baseName, String name, ChannelHandler handler);
 
@@ -304,7 +304,7 @@ public interface ChannelPipeline
      * @throws IllegalArgumentException
      *         if there's an entry with the same name already in the pipeline
      * @throws NullPointerException
-     *         if the specified baseName, name, or handler is {@code null}
+     *         if the specified baseName or handler is {@code null}
      */
     ChannelPipeline addBefore(EventExecutorGroup group, String baseName, String name, ChannelHandler handler);
 
@@ -321,7 +321,7 @@ public interface ChannelPipeline
      * @throws IllegalArgumentException
      *         if there's an entry with the same name already in the pipeline
      * @throws NullPointerException
-     *         if the specified baseName, name, or handler is {@code null}
+     *         if the specified baseName or handler is {@code null}
      */
     ChannelPipeline addAfter(String baseName, String name, ChannelHandler handler);
 
@@ -340,7 +340,7 @@ public interface ChannelPipeline
      * @throws IllegalArgumentException
      *         if there's an entry with the same name already in the pipeline
      * @throws NullPointerException
-     *         if the specified baseName, name, or handler is {@code null}
+     *         if the specified baseName or handler is {@code null}
      */
     ChannelPipeline addAfter(EventExecutorGroup group, String baseName, String name, ChannelHandler handler);
 
@@ -456,7 +456,7 @@ public interface ChannelPipeline
      *         if a handler with the specified new name already exists in this
      *         pipeline, except for the handler to be replaced
      * @throws NullPointerException
-     *         if the specified old handler, new name, or new handler is
+     *         if the specified old handler or new handler is
      *         {@code null}
      */
     ChannelPipeline replace(ChannelHandler oldHandler, String newName, ChannelHandler newHandler);
@@ -476,7 +476,7 @@ public interface ChannelPipeline
      *         if a handler with the specified new name already exists in this
      *         pipeline, except for the handler to be replaced
      * @throws NullPointerException
-     *         if the specified old handler, new name, or new handler is
+     *         if the specified old handler or new handler is
      *         {@code null}
      */
     ChannelHandler replace(String oldName, String newName, ChannelHandler newHandler);
@@ -497,7 +497,7 @@ public interface ChannelPipeline
      *         if a handler with the specified new name already exists in this
      *         pipeline, except for the handler to be replaced
      * @throws NullPointerException
-     *         if the specified old handler, new name, or new handler is
+     *         if the specified old handler or new handler is
      *         {@code null}
      */
     <T extends ChannelHandler> T replace(Class<T> oldHandlerType, String newName,

transport/src/main/java/io/netty/channel/DefaultChannelPipeline.java

@@ -145,12 +145,8 @@ public class DefaultChannelPipeline implements ChannelPipeline {
         final AbstractChannelHandlerContext newCtx;
         final EventExecutor executor;
         synchronized (this) {
-            if (name == null) {
-                name = generateName(handler);
-            } else {
-                checkDuplicateName(name);
-            }
             checkMultiplicity(handler);
+            name = filterName(name, handler);
 
             newCtx = newContext(group, name, handler);
             executor = executorSafe(newCtx.executor);
@@ -197,14 +193,9 @@ public class DefaultChannelPipeline implements ChannelPipeline {
         final EventExecutor executor;
         final AbstractChannelHandlerContext newCtx;
         synchronized (this) {
-            if (name == null) {
-                name = generateName(handler);
-            } else {
-                checkDuplicateName(name);
-            }
             checkMultiplicity(handler);
 
-            newCtx = newContext(group, name, handler);
+            newCtx = newContext(group, filterName(name, handler), handler);
             executor = executorSafe(newCtx.executor);
 
             addLast0(newCtx);
@@ -251,12 +242,8 @@ public class DefaultChannelPipeline implements ChannelPipeline {
         final AbstractChannelHandlerContext ctx;
         synchronized (this) {
             checkMultiplicity(handler);
+            name = filterName(name, handler);
             ctx = getContextOrDie(baseName);
-            if (name == null) {
-                name = generateName(handler);
-            } else {
-                checkDuplicateName(name);
-            }
 
             newCtx = newContext(group, name, handler);
             executor = executorSafe(newCtx.executor);
@@ -292,6 +279,14 @@ public class DefaultChannelPipeline implements ChannelPipeline {
         ctx.prev = newCtx;
     }
 
+    private String filterName(String name, ChannelHandler handler) {
+        if (name == null) {
+            return generateName(handler);
+        }
+        checkDuplicateName(name);
+        return name;
+    }
+
     @Override
     public final ChannelPipeline addAfter(String baseName, String name, ChannelHandler handler) {
         return addAfter(null, baseName, name, handler);
@@ -299,15 +294,15 @@ public class DefaultChannelPipeline implements ChannelPipeline {
 
     @Override
     public final ChannelPipeline addAfter(
-            EventExecutorGroup group, String baseName, final String name, ChannelHandler handler) {
+            EventExecutorGroup group, String baseName, String name, ChannelHandler handler) {
         final EventExecutor executor;
         final AbstractChannelHandlerContext newCtx;
         final AbstractChannelHandlerContext ctx;
 
         synchronized (this) {
             checkMultiplicity(handler);
+            name = filterName(name, handler);
             ctx = getContextOrDie(baseName);
-            checkDuplicateName(name);
 
             newCtx = newContext(group, name, handler);
             executor = executorSafe(newCtx.executor);
@@ -365,7 +360,7 @@ public class DefaultChannelPipeline implements ChannelPipeline {
 
         for (int i = size - 1; i >= 0; i --) {
             ChannelHandler h = handlers[i];
-            addFirst(executor, generateName(h), h);
+            addFirst(executor, null, h);
         }
 
         return this;
@@ -386,7 +381,7 @@ public class DefaultChannelPipeline implements ChannelPipeline {
             if (h == null) {
                 break;
             }
-            addLast(executor, generateName(h), h);
+            addLast(executor, null, h);
         }
 
         return this;

transport/src/test/java/io/netty/channel/DefaultChannelPipelineTest.java

@@ -879,6 +879,20 @@ public class DefaultChannelPipelineTest {
         }
     }
 
+    @Test
+    public void testNullName() {
+        ChannelPipeline pipeline = new LocalChannel().pipeline();
+        pipeline.addLast(newHandler());
+        pipeline.addLast(null, newHandler());
+        pipeline.addFirst(newHandler());
+        pipeline.addFirst(null, newHandler());
+
+        pipeline.addLast("test", newHandler());
+        pipeline.addAfter("test", null, newHandler());
+
+        pipeline.addBefore("test", null, newHandler());
+    }
+
     private static final class TestTask implements Runnable {
 
         private final ChannelPipeline pipeline;