From c229a55ad9acd6d78a9a624ab3fccb666264dbf3 Mon Sep 17 00:00:00 2001
From: Greg Wilkins <gregw@webtide.com>
Date: Mon, 28 Nov 2011 14:00:35 +1100
Subject: [PATCH] 362742 improved UTF8 exception reason

---
 .../eclipse/jetty/util/Utf8Appendable.java    | 53 +++++++++++--------
 1 file changed, 30 insertions(+), 23 deletions(-)

diff --git a/jetty-util/src/main/java/org/eclipse/jetty/util/Utf8Appendable.java b/jetty-util/src/main/java/org/eclipse/jetty/util/Utf8Appendable.java
index 306b6bff125..8fe840c1b88 100644
--- a/jetty-util/src/main/java/org/eclipse/jetty/util/Utf8Appendable.java
+++ b/jetty-util/src/main/java/org/eclipse/jetty/util/Utf8Appendable.java
@@ -134,7 +134,7 @@ public abstract class Utf8Appendable
     protected void appendByte(byte b) throws IOException
     {
 
-        if (b > 0 && isUtf8SequenceComplete())
+        if (b > 0 && _state == UTF8_ACCEPT)
         {
             _appendable.append((char)(b & 0xFF));
         }
@@ -142,41 +142,48 @@ public abstract class Utf8Appendable
         {
             int i = b & 0xFF;
             int type = BYTE_TABLE[i];
-            _codep = isUtf8SequenceComplete() ? (0xFF >> type) & i : (i & 0x3F) | (_codep << 6);
-            _state = TRANS_TABLE[_state + type];
+            _codep = _state == UTF8_ACCEPT ? (0xFF >> type) & i : (i & 0x3F) | (_codep << 6);
+            int next = TRANS_TABLE[_state + type];
 
-            if (isUtf8SequenceComplete())
+            switch(next)
             {
-                if (_codep < Character.MIN_HIGH_SURROGATE)
-                {
-                    _appendable.append((char)_codep);
-                }
-                else
-                {
-                    for (char c : Character.toChars(_codep))
-                        _appendable.append(c);
-                }
-            }
-            else if (_state == UTF8_REJECT)
-            {
-                _codep=0;
-                _state = UTF8_ACCEPT;
-                _appendable.append(REPLACEMENT);
-                throw new NotUtf8Exception();
+                case UTF8_ACCEPT:
+                    _state=next;
+                    if (_codep < Character.MIN_HIGH_SURROGATE)
+                    {
+                        _appendable.append((char)_codep);
+                    }
+                    else
+                    {
+                        for (char c : Character.toChars(_codep))
+                            _appendable.append(c);
+                    }
+                    break;
+                    
+                case UTF8_REJECT:
+                    String reason = "byte "+TypeUtil.toHexString(b)+" in state "+(_state/12);
+                    _codep=0;
+                    _state = UTF8_ACCEPT;
+                    _appendable.append(REPLACEMENT);
+                    throw new NotUtf8Exception(reason);
+                    
+                default:
+                    _state=next;
+                    
             }
         }
     }
 
-    protected boolean isUtf8SequenceComplete()
+    public boolean isUtf8SequenceComplete()
     {
         return _state == UTF8_ACCEPT;
     }
 
     public static class NotUtf8Exception extends IllegalArgumentException
     {
-        public NotUtf8Exception()
+        public NotUtf8Exception(String reason)
         {
-            super("Not valid UTF8!");
+            super("Not valid UTF8! "+reason);
         }
     }
 }