Index: catalina/src/share/org/apache/catalina/connector/CoyoteReader.java
===================================================================
--- catalina/src/share/org/apache/catalina/connector/CoyoteReader.java	(revision 638800)
+++ catalina/src/share/org/apache/catalina/connector/CoyoteReader.java	(working copy)
@@ -119,7 +119,7 @@
 
 
     public boolean markSupported() {
-        return true;
+        return ib.markSupported();
     }
 
 
Index: catalina/src/share/org/apache/catalina/connector/InputBuffer.java
===================================================================
--- catalina/src/share/org/apache/catalina/connector/InputBuffer.java	(revision 638800)
+++ catalina/src/share/org/apache/catalina/connector/InputBuffer.java	(working copy)
@@ -227,15 +227,14 @@
     }
 
 
-    public int available()
-        throws IOException {
+    public int available() {
+        int available = 0;
         if (state == BYTE_STATE) {
-            return bb.getLength();
+            available = bb.getLength();
         } else if (state == CHAR_STATE) {
-            return cb.getLength();
-        } else {
-            return 0;
+            available = cb.getLength();
         }
+        return available;
     }
 
 
@@ -308,21 +307,29 @@
         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();
 
     }
@@ -380,7 +387,7 @@
 
     public boolean ready()
         throws IOException {
-        return (cb.getLength() > 0);
+        return (available() > 0);
     }
 
 
@@ -391,6 +398,9 @@
 
     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);
@@ -416,9 +426,7 @@
         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);
             }