Move location of where oversized headers that don't exceed the go away limit is done

so that the check occurs after all headers have been read

codec-http2/src/main/java/io/netty/handler/codec/http2/internal/hpack/Decoder.java

@@ -295,12 +295,15 @@ public final class Decoder {
                 default:
                     throw new Error("should not reach here state: " + state);
             }
+        }
 
+        // we have read all of our headers, and not exceeded maxHeaderListSizeGoAway see if we have
+        // exceeded our actual maxHeaderListSize. This must be done here to prevent dynamic table
+        // corruption
         if (headersLength > maxHeaderListSize) {
             headerListSizeExceeded(streamId, maxHeaderListSize, true);
         }
     }
-    }
 
     /**
      * Set the maximum table size. If this is below the maximum size of the dynamic table used by

codec-http2/src/test/java/io/netty/handler/codec/http2/internal/hpack/DecoderTest.java

@@ -33,16 +33,20 @@ package io.netty.handler.codec.http2.internal.hpack;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.Unpooled;
+import io.netty.handler.codec.http2.DefaultHttp2Headers;
 import io.netty.handler.codec.http2.Http2Exception;
 import io.netty.handler.codec.http2.Http2Headers;
 import org.junit.Before;
 import org.junit.Test;
 
+import static io.netty.handler.codec.http2.Http2HeadersEncoder.NEVER_SENSITIVE;
 import static io.netty.handler.codec.http2.internal.hpack.Decoder.decodeULE128;
 import static io.netty.util.AsciiString.EMPTY_STRING;
 import static io.netty.util.AsciiString.of;
 import static java.lang.Integer.MAX_VALUE;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.reset;
 import static org.mockito.Mockito.times;
@@ -419,4 +423,38 @@ public class DecoderTest {
         }
         decode(sb.toString());
     }
+
+    @Test
+    public void testDecodeLargerThanMaxHeaderListSizeButSmallerThanMaxHeaderListSizeUpdatesDynamicTable()
+        throws Http2Exception {
+        ByteBuf in = Unpooled.buffer(200);
+        try {
+            decoder.setMaxHeaderListSize(100, 200);
+            Encoder encoder = new Encoder(true);
+
+            // encode headers that are slightly larger than maxHeaderListSize
+            // but smaller than maxHeaderListSizeGoAway
+            Http2Headers toEncode = new DefaultHttp2Headers();
+            toEncode.add("test_1", "1");
+            toEncode.add("test_2", "2");
+            toEncode.add("long", String.format("%0100d", 0).replace('0', 'A'));
+            toEncode.add("test_3", "3");
+            encoder.encodeHeaders(1, in, toEncode, NEVER_SENSITIVE);
+
+            // decode the headers, we should get an exception, but
+            // the decoded headers object should contain all of the headers
+            Http2Headers decoded = new DefaultHttp2Headers();
+            try {
+                decoder.decode(1, in, decoded);
+                fail();
+            } catch (Http2Exception e) {
+                assertTrue(e instanceof Http2Exception.HeaderListSizeException);
+            }
+
+            assertEquals(4, decoded.size());
+            assertTrue(decoded.contains("test_3"));
+        } finally {
+            in.release();
+        }
+    }
 }