diff --git a/string/public/nsReadableUtils.h b/string/public/nsReadableUtils.h
index ebc59cf9011..a9f39d0b0e9 100755
--- a/string/public/nsReadableUtils.h
+++ b/string/public/nsReadableUtils.h
@@ -17,18 +17,23 @@
  * Copyright (C) 2000 Netscape Communications Corporation. All
  * Rights Reserved.
  *
- * Original Author:
- *   Scott Collins <scc@mozilla.org>
- *
  * Contributor(s):
+ *   Scott Collins <scc@mozilla.org> (original author)
+ *   Johnny Stenbeck <jst@netscape.com>
+ *
  */
 
 #ifndef nsReadableUtils_h___
 #define nsReadableUtils_h___
 
-#include "nsAReadableString.h"
+  /**
+   * I guess all the routines in this file are all mis-named.
+   * According to our conventions, they should be |NS_xxx|.
+   */
+
+#ifndef nsAWritableString_h___
 #include "nsAWritableString.h"
-#include "nsCRT.h"
+#endif
 
 NS_COM void CopyUCS2toASCII( const nsAReadableString& aSource, nsAWritableCString& aDest );
 NS_COM void CopyASCIItoUCS2( const nsAReadableCString& aSource, nsAWritableString& aDest );
@@ -121,53 +126,14 @@ NS_COM PRUnichar* CopyUnicodeTo( const nsAReadableString& aSource,
 NS_COM PRBool IsASCII( const nsAReadableString& aString );
 
 
-  //
-  // |ToUpperCase(basic_nsAWritableString<CharT>&)|
-  //
-template <class CharT>
-void
-ToUpperCase(basic_nsAWritableString<CharT>& aString)
-  {
-    nsWritingIterator<CharT> start( aString.BeginWriting() );
-    nsWritingIterator<CharT> end( aString.EndWriting() );
 
-    while ( start != end ) {
-      PRUint32 fraglen = start.size_forward();
-      PRUint32 num_bytes = fraglen;
-      CharT *buf = start.get();
-
-      while ( num_bytes-- ) {
-        *buf = nsCRT::ToUpper(*buf);
-        ++buf;
-      }
-
-      start += fraglen;
-    }
-  }
-
-  //
-  // |ToUpperCase(basic_nsAWritableString<CharT>&)|
-  //
-template <class CharT>
-void
-ToLowerCase(basic_nsAWritableString<CharT>& aString)
-  {
-    nsWritingIterator<CharT> start( aString.BeginWriting() );
-    nsWritingIterator<CharT> end( aString.EndWriting() );
-
-    while ( start != end ) {
-      PRUint32 fraglen = start.size_forward();
-      PRUint32 num_bytes = fraglen;
-      CharT *buf = start.get();
-
-      while ( num_bytes-- ) {
-        *buf = nsCRT::ToLower(*buf);
-        ++buf;
-      }
-
-      start += fraglen;
-    }
-  }
+  /**
+   * Converts case in place in the argument string.
+   */
+NS_COM void ToUpperCase( nsAWritableString& );
+NS_COM void ToUpperCase( nsAWritableCString& );
 
+NS_COM void ToLowerCase( nsAWritableString& );
+NS_COM void ToLowerCase( nsAWritableCString& );
 
 #endif // !defined(nsReadableUtils_h___)
diff --git a/string/src/nsReadableUtils.cpp b/string/src/nsReadableUtils.cpp
index e356d39f08b..5527e1e48c8 100755
--- a/string/src/nsReadableUtils.cpp
+++ b/string/src/nsReadableUtils.cpp
@@ -24,6 +24,7 @@
 #include "nsReadableUtils.h"
 #include "nsMemory.h"
 #include "nsString.h"
+#include "nsCRT.h"
 
 
 
@@ -214,7 +215,7 @@ IsASCII( const nsAReadableString& aString )
     nsReadingIterator<PRUnichar> iter;
     for ( aString.BeginReading(iter); iter != done_reading; iter.advance( PRInt32(fragmentLength) ) )
       {
-        fragmentLength = iter.size_forward();
+        fragmentLength = PRUint32(iter.size_forward());
         const PRUnichar* c = iter.get();
         const PRUnichar* fragmentEnd = c + fragmentLength;
 
@@ -227,3 +228,77 @@ IsASCII( const nsAReadableString& aString )
     return PR_TRUE;
   }
 
+
+
+  /**
+   * A character sink for case conversion.
+   */
+template <class CharT>
+class ConvertToUpperCase
+  {
+    public:
+      typedef CharT value_type;
+
+      PRUint32
+      write( const CharT* aSource, PRUint32 aSourceLength )
+        {
+          for ( int i=0; i<aSourceLength; ++i )
+            NS_CONST_CAST(CharT*, aSource)[i] = nsCRT::ToUpper(aSource[i]);
+          return aSourceLength;
+        }
+  };
+
+NS_COM
+void
+ToUpperCase( nsAWritableString& aString )
+  {
+    nsAWritableString::iterator fromBegin, fromEnd;
+    ConvertToUpperCase<PRUnichar> converter;
+    copy_string(aString.BeginWriting(fromBegin), aString.EndWriting(fromEnd), converter);
+  }
+
+NS_COM
+void
+ToUpperCase( nsAWritableCString& aCString )
+  {
+    nsAWritableCString::iterator fromBegin, fromEnd;
+    ConvertToUpperCase<char> converter;
+    copy_string(aCString.BeginWriting(fromBegin), aCString.EndWriting(fromEnd), converter);
+  }
+
+
+  /**
+   * A character sink for case conversion.
+   */
+template <class CharT>
+class ConvertToLowerCase
+  {
+    public:
+      typedef CharT value_type;
+
+      PRUint32
+      write( const CharT* aSource, PRUint32 aSourceLength )
+        {
+          for ( int i=0; i<aSourceLength; ++i )
+            NS_CONST_CAST(CharT*, aSource)[i] = nsCRT::ToLower(aSource[i]);
+          return aSourceLength;
+        }
+  };
+
+NS_COM
+void
+ToLowerCase( nsAWritableString& aString )
+  {
+    nsAWritableString::iterator fromBegin, fromEnd;
+    ConvertToLowerCase<PRUnichar> converter;
+    copy_string(aString.BeginWriting(fromBegin), aString.EndWriting(fromEnd), converter);
+  }
+
+NS_COM
+void
+ToLowerCase( nsAWritableCString& aCString )
+  {
+    nsAWritableCString::iterator fromBegin, fromEnd;
+    ConvertToLowerCase<char> converter;
+    copy_string(aCString.BeginWriting(fromBegin), aCString.EndWriting(fromEnd), converter);
+  }
diff --git a/xpcom/ds/nsReadableUtils.cpp b/xpcom/ds/nsReadableUtils.cpp
index e356d39f08b..5527e1e48c8 100755
--- a/xpcom/ds/nsReadableUtils.cpp
+++ b/xpcom/ds/nsReadableUtils.cpp
@@ -24,6 +24,7 @@
 #include "nsReadableUtils.h"
 #include "nsMemory.h"
 #include "nsString.h"
+#include "nsCRT.h"
 
 
 
@@ -214,7 +215,7 @@ IsASCII( const nsAReadableString& aString )
     nsReadingIterator<PRUnichar> iter;
     for ( aString.BeginReading(iter); iter != done_reading; iter.advance( PRInt32(fragmentLength) ) )
       {
-        fragmentLength = iter.size_forward();
+        fragmentLength = PRUint32(iter.size_forward());
         const PRUnichar* c = iter.get();
         const PRUnichar* fragmentEnd = c + fragmentLength;
 
@@ -227,3 +228,77 @@ IsASCII( const nsAReadableString& aString )
     return PR_TRUE;
   }
 
+
+
+  /**
+   * A character sink for case conversion.
+   */
+template <class CharT>
+class ConvertToUpperCase
+  {
+    public:
+      typedef CharT value_type;
+
+      PRUint32
+      write( const CharT* aSource, PRUint32 aSourceLength )
+        {
+          for ( int i=0; i<aSourceLength; ++i )
+            NS_CONST_CAST(CharT*, aSource)[i] = nsCRT::ToUpper(aSource[i]);
+          return aSourceLength;
+        }
+  };
+
+NS_COM
+void
+ToUpperCase( nsAWritableString& aString )
+  {
+    nsAWritableString::iterator fromBegin, fromEnd;
+    ConvertToUpperCase<PRUnichar> converter;
+    copy_string(aString.BeginWriting(fromBegin), aString.EndWriting(fromEnd), converter);
+  }
+
+NS_COM
+void
+ToUpperCase( nsAWritableCString& aCString )
+  {
+    nsAWritableCString::iterator fromBegin, fromEnd;
+    ConvertToUpperCase<char> converter;
+    copy_string(aCString.BeginWriting(fromBegin), aCString.EndWriting(fromEnd), converter);
+  }
+
+
+  /**
+   * A character sink for case conversion.
+   */
+template <class CharT>
+class ConvertToLowerCase
+  {
+    public:
+      typedef CharT value_type;
+
+      PRUint32
+      write( const CharT* aSource, PRUint32 aSourceLength )
+        {
+          for ( int i=0; i<aSourceLength; ++i )
+            NS_CONST_CAST(CharT*, aSource)[i] = nsCRT::ToLower(aSource[i]);
+          return aSourceLength;
+        }
+  };
+
+NS_COM
+void
+ToLowerCase( nsAWritableString& aString )
+  {
+    nsAWritableString::iterator fromBegin, fromEnd;
+    ConvertToLowerCase<PRUnichar> converter;
+    copy_string(aString.BeginWriting(fromBegin), aString.EndWriting(fromEnd), converter);
+  }
+
+NS_COM
+void
+ToLowerCase( nsAWritableCString& aCString )
+  {
+    nsAWritableCString::iterator fromBegin, fromEnd;
+    ConvertToLowerCase<char> converter;
+    copy_string(aCString.BeginWriting(fromBegin), aCString.EndWriting(fromEnd), converter);
+  }
diff --git a/xpcom/ds/nsReadableUtils.h b/xpcom/ds/nsReadableUtils.h
index ebc59cf9011..a9f39d0b0e9 100755
--- a/xpcom/ds/nsReadableUtils.h
+++ b/xpcom/ds/nsReadableUtils.h
@@ -17,18 +17,23 @@
  * Copyright (C) 2000 Netscape Communications Corporation. All
  * Rights Reserved.
  *
- * Original Author:
- *   Scott Collins <scc@mozilla.org>
- *
  * Contributor(s):
+ *   Scott Collins <scc@mozilla.org> (original author)
+ *   Johnny Stenbeck <jst@netscape.com>
+ *
  */
 
 #ifndef nsReadableUtils_h___
 #define nsReadableUtils_h___
 
-#include "nsAReadableString.h"
+  /**
+   * I guess all the routines in this file are all mis-named.
+   * According to our conventions, they should be |NS_xxx|.
+   */
+
+#ifndef nsAWritableString_h___
 #include "nsAWritableString.h"
-#include "nsCRT.h"
+#endif
 
 NS_COM void CopyUCS2toASCII( const nsAReadableString& aSource, nsAWritableCString& aDest );
 NS_COM void CopyASCIItoUCS2( const nsAReadableCString& aSource, nsAWritableString& aDest );
@@ -121,53 +126,14 @@ NS_COM PRUnichar* CopyUnicodeTo( const nsAReadableString& aSource,
 NS_COM PRBool IsASCII( const nsAReadableString& aString );
 
 
-  //
-  // |ToUpperCase(basic_nsAWritableString<CharT>&)|
-  //
-template <class CharT>
-void
-ToUpperCase(basic_nsAWritableString<CharT>& aString)
-  {
-    nsWritingIterator<CharT> start( aString.BeginWriting() );
-    nsWritingIterator<CharT> end( aString.EndWriting() );
 
-    while ( start != end ) {
-      PRUint32 fraglen = start.size_forward();
-      PRUint32 num_bytes = fraglen;
-      CharT *buf = start.get();
-
-      while ( num_bytes-- ) {
-        *buf = nsCRT::ToUpper(*buf);
-        ++buf;
-      }
-
-      start += fraglen;
-    }
-  }
-
-  //
-  // |ToUpperCase(basic_nsAWritableString<CharT>&)|
-  //
-template <class CharT>
-void
-ToLowerCase(basic_nsAWritableString<CharT>& aString)
-  {
-    nsWritingIterator<CharT> start( aString.BeginWriting() );
-    nsWritingIterator<CharT> end( aString.EndWriting() );
-
-    while ( start != end ) {
-      PRUint32 fraglen = start.size_forward();
-      PRUint32 num_bytes = fraglen;
-      CharT *buf = start.get();
-
-      while ( num_bytes-- ) {
-        *buf = nsCRT::ToLower(*buf);
-        ++buf;
-      }
-
-      start += fraglen;
-    }
-  }
+  /**
+   * Converts case in place in the argument string.
+   */
+NS_COM void ToUpperCase( nsAWritableString& );
+NS_COM void ToUpperCase( nsAWritableCString& );
 
+NS_COM void ToLowerCase( nsAWritableString& );
+NS_COM void ToLowerCase( nsAWritableCString& );
 
 #endif // !defined(nsReadableUtils_h___)
diff --git a/xpcom/string/public/nsReadableUtils.h b/xpcom/string/public/nsReadableUtils.h
index ebc59cf9011..a9f39d0b0e9 100755
--- a/xpcom/string/public/nsReadableUtils.h
+++ b/xpcom/string/public/nsReadableUtils.h
@@ -17,18 +17,23 @@
  * Copyright (C) 2000 Netscape Communications Corporation. All
  * Rights Reserved.
  *
- * Original Author:
- *   Scott Collins <scc@mozilla.org>
- *
  * Contributor(s):
+ *   Scott Collins <scc@mozilla.org> (original author)
+ *   Johnny Stenbeck <jst@netscape.com>
+ *
  */
 
 #ifndef nsReadableUtils_h___
 #define nsReadableUtils_h___
 
-#include "nsAReadableString.h"
+  /**
+   * I guess all the routines in this file are all mis-named.
+   * According to our conventions, they should be |NS_xxx|.
+   */
+
+#ifndef nsAWritableString_h___
 #include "nsAWritableString.h"
-#include "nsCRT.h"
+#endif
 
 NS_COM void CopyUCS2toASCII( const nsAReadableString& aSource, nsAWritableCString& aDest );
 NS_COM void CopyASCIItoUCS2( const nsAReadableCString& aSource, nsAWritableString& aDest );
@@ -121,53 +126,14 @@ NS_COM PRUnichar* CopyUnicodeTo( const nsAReadableString& aSource,
 NS_COM PRBool IsASCII( const nsAReadableString& aString );
 
 
-  //
-  // |ToUpperCase(basic_nsAWritableString<CharT>&)|
-  //
-template <class CharT>
-void
-ToUpperCase(basic_nsAWritableString<CharT>& aString)
-  {
-    nsWritingIterator<CharT> start( aString.BeginWriting() );
-    nsWritingIterator<CharT> end( aString.EndWriting() );
 
-    while ( start != end ) {
-      PRUint32 fraglen = start.size_forward();
-      PRUint32 num_bytes = fraglen;
-      CharT *buf = start.get();
-
-      while ( num_bytes-- ) {
-        *buf = nsCRT::ToUpper(*buf);
-        ++buf;
-      }
-
-      start += fraglen;
-    }
-  }
-
-  //
-  // |ToUpperCase(basic_nsAWritableString<CharT>&)|
-  //
-template <class CharT>
-void
-ToLowerCase(basic_nsAWritableString<CharT>& aString)
-  {
-    nsWritingIterator<CharT> start( aString.BeginWriting() );
-    nsWritingIterator<CharT> end( aString.EndWriting() );
-
-    while ( start != end ) {
-      PRUint32 fraglen = start.size_forward();
-      PRUint32 num_bytes = fraglen;
-      CharT *buf = start.get();
-
-      while ( num_bytes-- ) {
-        *buf = nsCRT::ToLower(*buf);
-        ++buf;
-      }
-
-      start += fraglen;
-    }
-  }
+  /**
+   * Converts case in place in the argument string.
+   */
+NS_COM void ToUpperCase( nsAWritableString& );
+NS_COM void ToUpperCase( nsAWritableCString& );
 
+NS_COM void ToLowerCase( nsAWritableString& );
+NS_COM void ToLowerCase( nsAWritableCString& );
 
 #endif // !defined(nsReadableUtils_h___)
diff --git a/xpcom/string/src/nsReadableUtils.cpp b/xpcom/string/src/nsReadableUtils.cpp
index e356d39f08b..5527e1e48c8 100755
--- a/xpcom/string/src/nsReadableUtils.cpp
+++ b/xpcom/string/src/nsReadableUtils.cpp
@@ -24,6 +24,7 @@
 #include "nsReadableUtils.h"
 #include "nsMemory.h"
 #include "nsString.h"
+#include "nsCRT.h"
 
 
 
@@ -214,7 +215,7 @@ IsASCII( const nsAReadableString& aString )
     nsReadingIterator<PRUnichar> iter;
     for ( aString.BeginReading(iter); iter != done_reading; iter.advance( PRInt32(fragmentLength) ) )
       {
-        fragmentLength = iter.size_forward();
+        fragmentLength = PRUint32(iter.size_forward());
         const PRUnichar* c = iter.get();
         const PRUnichar* fragmentEnd = c + fragmentLength;
 
@@ -227,3 +228,77 @@ IsASCII( const nsAReadableString& aString )
     return PR_TRUE;
   }
 
+
+
+  /**
+   * A character sink for case conversion.
+   */
+template <class CharT>
+class ConvertToUpperCase
+  {
+    public:
+      typedef CharT value_type;
+
+      PRUint32
+      write( const CharT* aSource, PRUint32 aSourceLength )
+        {
+          for ( int i=0; i<aSourceLength; ++i )
+            NS_CONST_CAST(CharT*, aSource)[i] = nsCRT::ToUpper(aSource[i]);
+          return aSourceLength;
+        }
+  };
+
+NS_COM
+void
+ToUpperCase( nsAWritableString& aString )
+  {
+    nsAWritableString::iterator fromBegin, fromEnd;
+    ConvertToUpperCase<PRUnichar> converter;
+    copy_string(aString.BeginWriting(fromBegin), aString.EndWriting(fromEnd), converter);
+  }
+
+NS_COM
+void
+ToUpperCase( nsAWritableCString& aCString )
+  {
+    nsAWritableCString::iterator fromBegin, fromEnd;
+    ConvertToUpperCase<char> converter;
+    copy_string(aCString.BeginWriting(fromBegin), aCString.EndWriting(fromEnd), converter);
+  }
+
+
+  /**
+   * A character sink for case conversion.
+   */
+template <class CharT>
+class ConvertToLowerCase
+  {
+    public:
+      typedef CharT value_type;
+
+      PRUint32
+      write( const CharT* aSource, PRUint32 aSourceLength )
+        {
+          for ( int i=0; i<aSourceLength; ++i )
+            NS_CONST_CAST(CharT*, aSource)[i] = nsCRT::ToLower(aSource[i]);
+          return aSourceLength;
+        }
+  };
+
+NS_COM
+void
+ToLowerCase( nsAWritableString& aString )
+  {
+    nsAWritableString::iterator fromBegin, fromEnd;
+    ConvertToLowerCase<PRUnichar> converter;
+    copy_string(aString.BeginWriting(fromBegin), aString.EndWriting(fromEnd), converter);
+  }
+
+NS_COM
+void
+ToLowerCase( nsAWritableCString& aCString )
+  {
+    nsAWritableCString::iterator fromBegin, fromEnd;
+    ConvertToLowerCase<char> converter;
+    copy_string(aCString.BeginWriting(fromBegin), aCString.EndWriting(fromEnd), converter);
+  }