Index: java/org/apache/catalina/connector/CoyoteReader.java
===================================================================
--- java/org/apache/catalina/connector/CoyoteReader.java	(revision 638800)
+++ java/org/apache/catalina/connector/CoyoteReader.java	(working copy)
@@ -119,7 +119,7 @@
 
 
     public boolean markSupported() {
-        return true;
+        return ib.markSupported();
     }
 
 
Index: java/org/apache/catalina/connector/InputBuffer.java
===================================================================
--- java/org/apache/catalina/connector/InputBuffer.java	(revision 638800)
+++ java/org/apache/catalina/connector/InputBuffer.java	(working copy)
@@ -342,22 +342,29 @@
         if (!gotEnc)
             setConverter();
 
+        int nRead = 0;
         if (bb.getLength() <= 0) {
-            int nRead = realReadBytes(bb.getBytes(), 0, bb.getBytes().length);
-            if (nRead < 0) {
-                return -1;
-            }
+            nRead = realReadBytes(bb.getBytes(), 0, bb.getBytes().length);
+            // Data may be remaining in the buffer of ReadConverter('s super).
+            // So we must try to convert whether nRead is positive or not.
         }
-
         if (markPos == -1) {
             cb.setOffset(0);
             cb.setEnd(0);
         }
 
+        if((markPos >= 0) && (cb.getLimit()-cb.getEnd()) <= 0){
+            // markPos will be reset and the status of cb will be modified
+            // via cb.flushBuffer(), only if more chars exists.
+            conv.convert(bb, cb, cb.getLimit());
+        }else{
+        conv.convert(bb, cb, cb.getLimit()-cb.getEnd());
+        }
         state = CHAR_STATE;
-        conv.convert(bb, cb, len);
-        bb.setOffset(bb.getEnd());
 
+        if((nRead < 0) && (cb.getLength()==0)){
+            return -1;
+        }
         return cb.getLength();
 
     }
@@ -426,6 +433,9 @@
 
     public void mark(int readAheadLimit)
         throws IOException {
+        if (readAheadLimit < 0){ // See BufferedReader#mark(int) JavaDoc
+            throw new IllegalArgumentException("readAheadLimit value is negative");
+        }
         if (cb.getLength() <= 0) {
             cb.setOffset(0);
             cb.setEnd(0);
@@ -451,9 +461,7 @@
         throws IOException {
         if (state == CHAR_STATE) {
             if (markPos < 0) {
-                cb.recycle();
-                markPos = -1;
-                throw new IOException();
+                throw new IOException("The mark is not effective");
             } else {
                 cb.setOffset(markPos);
             }
Index: java/org/apache/tomcat/util/buf/B2CConverter.java
===================================================================
--- java/org/apache/tomcat/util/buf/B2CConverter.java	(revision 638800)
+++ java/org/apache/tomcat/util/buf/B2CConverter.java	(working copy)
@@ -73,13 +73,15 @@
     public  void convert( ByteChunk bb, CharChunk cb )
 	throws IOException
     {
-	// Set the ByteChunk as input to the Intermediate reader
-	convert(bb, cb, cb.getBuffer().length - cb.getEnd());
+        convert(bb, cb, cb.getLimit() - cb.getEnd());
     }
 
-    public void convert( ByteChunk bb, CharChunk cb, int limit) 
-        throws IOException
+    /** Convert a buffer of bytes into a chars
+     */
+    public void convert( ByteChunk bb, CharChunk cb, int limit)
+    throws IOException
     {
+        // Set the ByteChunk as input to the Intermediate reader
         iis.setByteChunk( bb );
         convert(cb, limit);
     }
@@ -89,10 +91,9 @@
     {
 	try {
 	    // read from the reader
-            int count = 0;
-	    while( limit > 0 ) { // conv.ready() ) {
-                int size = limit < BUFFER_SIZE ? limit : BUFFER_SIZE;
-		int cnt=conv.read( result, 0, size );
+        while( limit > 0 ) { 
+        int size = limit < BUFFER_SIZE ? limit : BUFFER_SIZE;
+        int cnt=conv.read( result, 0, size );
 		if( cnt <= 0 ) {
 		    // End of stream ! - we may be in a bad state
 		    if( debug>0)
@@ -105,7 +106,7 @@
 
 		// XXX go directly
 		cb.append( result, 0, cnt );
-                limit -= cnt;
+        limit -= cnt;
 	    }
 	} catch( IOException ex) {
 	    if( debug>0)
@@ -193,18 +194,16 @@
  * 
  */
 final class  ReadConvertor extends InputStreamReader {
-    // stream with flush() and close(). overriden.
+    
     private IntermediateInputStream iis;
-    
-    // Has a private, internal byte[8192]
-    
+
     /** Create a converter.
      */
     public ReadConvertor( IntermediateInputStream in, String enc )
 	throws UnsupportedEncodingException
     {
 	super( in, enc );
-	iis=in;
+    iis=in;
     }
     
     /** Overriden - will do nothing but reset internal state.
@@ -221,9 +220,18 @@
 	return super.read( cbuf, off, len );
     }
     
-    /** Reset the buffer
+    /*
+     * Reset the buffer
      */
     public  final void recycle() {
+        iis.recycle();
+        try{
+           // Must clear super's buffer.
+            while(ready()){
+                // InputStreamReader#skip(long) will allocate buffer to skip.
+                read();
+            }
+        }catch(IOException ioe){}
     }
 }
 
@@ -246,15 +254,32 @@
     }
     
     public  final  int read(byte cbuf[], int off, int len) throws IOException {
-	return bc.substract(cbuf, off, len);
+        if(bc == null){
+            return -1;
+        }
+        return bc.substract(cbuf, off, len);
     }
     
     public  final int read() throws IOException {
-	return bc.substract();
+        if(bc == null){
+            return -1;
+        }
+        return bc.substract();
     }
+    
+    public int available() throws IOException {
+        if(bc == null){
+            return 0;
+        }
+        return bc.getLength();
+    }
 
+
     // -------------------- Internal methods --------------------
 
+    void recycle(){
+        bc = null;
+    }
 
     void setByteChunk( ByteChunk mb ) {
         bc = mb;