diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index 72ec7f4099..9f8edc9385 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -1,3 +1,25 @@
+19991121-17:33 GMT+1 Victor Szel <info@szelvesz.hu>
+  * source/compiler/expropt.c
+    ! $ optimization fixed for strings containing Chr(0), now 4 more RTL_TESTs
+      pass.
+    ! "Fixed" CHR() to be bug compatible with Clipper for cases where param
+       % 256 = 0 but param != 0.
+    ! "Fixed" $ to be bug compatible with Clipper when an empty string is
+       searched in a string.
+  * tests/rtl_test.prg (not yet committed)
+    + Some failing VAL() tests added.
+    ! Corrected result for compiler optimized AT(), CHR() and $ operations.
+      They now test for bug compatibility.
+  + source/common/hbstr.c (added)
+    source/common/Makefile
+    source/rtl/strings.c
+    * hb_strAt() moved to the common library.
+      ! WARNING ! Please modify non-GNU make systems.
+  * source/vm/hvm.c
+    % Minor optimization in hb_vmInString()
+  * source/pp/*
+    ! Fixed some mistyped #undef statements related to tracing.
+
 19991121-16:10 GMT+1 Bruno Cantero <bruno@issnet.net>
   * include/rddapi.h
     source/rdd/dbcmd.c
diff --git a/harbour/source/common/Makefile b/harbour/source/common/Makefile
index a78deded89..6dadb34c7d 100644
--- a/harbour/source/common/Makefile
+++ b/harbour/source/common/Makefile
@@ -6,6 +6,7 @@ ROOT = ../../
 
 C_SOURCES=\
         hbfsapi.c \
+        hbstr.c \
         hbtrace.c \
 
 PRG_SOURCES=\
diff --git a/harbour/source/common/hbstr.c b/harbour/source/common/hbstr.c
new file mode 100644
index 0000000000..cb3fbb5206
--- /dev/null
+++ b/harbour/source/common/hbstr.c
@@ -0,0 +1,63 @@
+/*
+ * $Id$
+ */
+
+/*
+ * Harbour Project source code:
+ * Harbour common string functions (accessed from standalone utilities and the RTL)
+ *
+ * Copyright 1999 Victor Szel <info@szelvesz.hu>
+ * www - http://www.harbour-project.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version, with one exception:
+ *
+ * The exception is that if you link the Harbour Runtime Library (HRL)
+ * and/or the Harbour Virtual Machine (HVM) with other files to produce
+ * an executable, this does not by itself cause the resulting executable
+ * to be covered by the GNU General Public License. Your use of that
+ * executable is in no way restricted on account of linking the HRL
+ * and/or HVM code into it.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA (or visit
+ * their web site at http://www.gnu.org/).
+ *
+ */
+
+#include "extend.h"
+
+ULONG hb_strAt( const char * szSub, ULONG ulSubLen, const char * szText, ULONG ulLen )
+{
+   HB_TRACE(HB_TR_DEBUG, ("hb_strAt(%s, %lu, %s, %lu)", szSub, ulSubLen, szText, ulLen));
+
+   if( ulSubLen > 0 && ulLen >= ulSubLen )
+   {
+      ULONG ulPos = 0, ulSubPos = 0;
+
+      while( ulPos < ulLen && ulSubPos < ulSubLen )
+      {
+         if( *( szText + ulPos ) == *( szSub + ulSubPos ) )
+         {
+            ulSubPos++;
+            ulPos++;
+         }
+         else if( ulSubPos )
+            ulSubPos = 0;
+         else
+            ulPos++;
+      }
+      return ( ulSubPos < ulSubLen ) ? 0 : ( ulPos - ulSubLen + 1 );
+   }
+   else
+      return 0;
+}
+
diff --git a/harbour/source/compiler/expropt.c b/harbour/source/compiler/expropt.c
index a8801c6c93..4da75515ed 100644
--- a/harbour/source/compiler/expropt.c
+++ b/harbour/source/compiler/expropt.c
@@ -592,6 +592,11 @@ HB_EXPR_PTR hb_compExprNewFunCall( char *szFunName, HB_EXPR_PTR pParms )
 
    hb_compFunCallCheck( szFunName, iCount );
 
+   /* TODO: AT() (also done by Clipper, already mentioned)
+            LEN() (also done by Clipper)
+            ASC() (not done by Clipper)
+            EMPTY() (not done by Clipper) */
+
    if( ( strcmp( "CHR", szFunName ) == 0 ) && iCount )
    {
       /* try to change it into a string */
@@ -599,15 +604,36 @@ HB_EXPR_PTR hb_compExprNewFunCall( char *szFunName, HB_EXPR_PTR pParms )
 
       if( pArg->ExprType == HB_ET_NUMERIC )
       {
+         /* NOTE: CA-Cl*pper's compiler optimizer will be wrong for those
+                  CHR() cases where the passed parameter is a constant which
+                  can be divided by 256 but it's not zero, in this case it
+                  will return an empty string instead of a Chr(0). [vszel] */
+
          pExpr = hb_compExprNew( HB_ET_STRING );
-         pExpr->ulLength = 1;
-         pExpr->ValType  = HB_EV_STRING;
-         pExpr->value.asString = ( char * ) HB_XGRAB( 2 );
+         pExpr->ValType = HB_EV_STRING;
          if( pArg->value.asNum.NumType == HB_ET_LONG )
-            pExpr->value.asString[ 0 ] = ( pArg->value.asNum.lVal % 256 );
+         {
+            if( ( pArg->value.asNum.lVal % 256 ) == 0 && pArg->value.asNum.lVal != 0 )
+            {
+               pExpr->value.asString = ( char * ) HB_XGRAB( 1 );
+               pExpr->value.asString[ 0 ] = '\0';
+               pExpr->ulLength = 0;
+            }
+            else
+            {
+               pExpr->value.asString = ( char * ) HB_XGRAB( 2 );
+               pExpr->value.asString[ 0 ] = ( pArg->value.asNum.lVal % 256 );
+               pExpr->value.asString[ 1 ] = '\0';
+               pExpr->ulLength = 1;
+            }
+         }
          else
-            pExpr->value.asString[ 0 ] = ( (long) pArg->value.asNum.dVal % 256 );
-         pExpr->value.asString[ 1 ] = '\x0';
+         {
+            pExpr->value.asString = ( char * ) HB_XGRAB( 2 );
+            pExpr->value.asString[ 0 ] = ( ( long ) pArg->value.asNum.dVal % 256 );
+            pExpr->value.asString[ 1 ] = '\0';
+            pExpr->ulLength = 1;
+         }
          hb_compExprDelete( pParms );
       }
    }
@@ -4003,7 +4029,15 @@ static HB_EXPR_FUNC( hb_compExprUseIN )
                 */
                BOOL bResult;
 
-               bResult = ( strstr( pSelf->value.asOperator.pRight->value.asString, pSelf->value.asOperator.pLeft->value.asString ) != NULL );
+               /* NOTE: CA-Cl*pper has a bug where the $ operator returns .T.
+                        when an empty string is searched [vszel] */
+
+               if( pSelf->value.asOperator.pLeft->ulLength == 0 )
+                  bResult = TRUE;
+               else
+                  bResult = ( hb_strAt( pSelf->value.asOperator.pLeft->value.asString, pSelf->value.asOperator.pLeft->ulLength,
+                                        pSelf->value.asOperator.pRight->value.asString, pSelf->value.asOperator.pRight->ulLength ) != 0 );
+
                /* NOTE:
                 * "" $ "XXX" = .T.
                 * "" $ "" = .T.
diff --git a/harbour/source/pp/hbppint.c b/harbour/source/pp/hbppint.c
index 9bd8726895..dc678c3f9e 100644
--- a/harbour/source/pp/hbppint.c
+++ b/harbour/source/pp/hbppint.c
@@ -38,7 +38,7 @@
  */
 #if ! defined(HB_TRACE_UTILS)
 #if defined(HB_TRACE_LEVEL)
-#undef HB_TRACE_LEVEL)
+#undef HB_TRACE_LEVEL
 #endif
 #endif
 
diff --git a/harbour/source/pp/hbpplib.c b/harbour/source/pp/hbpplib.c
index 358a7a769c..8988e43221 100644
--- a/harbour/source/pp/hbpplib.c
+++ b/harbour/source/pp/hbpplib.c
@@ -38,7 +38,7 @@
  */
 #if ! defined(HB_TRACE_UTILS)
 #if defined(HB_TRACE_LEVEL)
-#undef HB_TRACE_LEVEL)
+#undef HB_TRACE_LEVEL
 #endif
 #endif
 
diff --git a/harbour/source/pp/stdalone/hbpp.c b/harbour/source/pp/stdalone/hbpp.c
index d9afba73a1..8a580a93e0 100644
--- a/harbour/source/pp/stdalone/hbpp.c
+++ b/harbour/source/pp/stdalone/hbpp.c
@@ -38,7 +38,7 @@
  */
 #if ! defined(HB_TRACE_UTILS)
 #if defined(HB_TRACE_LEVEL)
-#undef HB_TRACE_LEVEL)
+#undef HB_TRACE_LEVEL
 #endif
 #endif
 
diff --git a/harbour/source/pp/table.c b/harbour/source/pp/table.c
index 739debafed..3f21848485 100644
--- a/harbour/source/pp/table.c
+++ b/harbour/source/pp/table.c
@@ -38,7 +38,7 @@
  */
 #if ! defined(HB_TRACE_UTILS)
 #if defined(HB_TRACE_LEVEL)
-#undef HB_TRACE_LEVEL)
+#undef HB_TRACE_LEVEL
 #endif
 #endif
 
diff --git a/harbour/source/rtl/strings.c b/harbour/source/rtl/strings.c
index 5a05f97262..06848862e1 100644
--- a/harbour/source/rtl/strings.c
+++ b/harbour/source/rtl/strings.c
@@ -535,32 +535,6 @@ HARBOUR HB_PADC( void )
       hb_retc( "" );
 }
 
-ULONG hb_strAt( const char * szSub, ULONG ulSubLen, const char * szText, ULONG ulLen )
-{
-   HB_TRACE(HB_TR_DEBUG, ("hb_strAt(%s, %lu, %s, %lu)", szSub, ulSubLen, szText, ulLen));
-
-   if( ulSubLen > 0 && ulLen >= ulSubLen )
-   {
-      ULONG ulPos = 0, ulSubPos = 0;
-
-      while( ulPos < ulLen && ulSubPos < ulSubLen )
-      {
-         if( *( szText + ulPos ) == *( szSub + ulSubPos ) )
-         {
-            ulSubPos++;
-            ulPos++;
-         }
-         else if( ulSubPos )
-            ulSubPos = 0;
-         else
-            ulPos++;
-      }
-      return ( ulSubPos < ulSubLen ) ? 0 : ( ulPos - ulSubLen + 1 );
-   }
-   else
-      return 0;
-}
-
 /* locates a substring in a string */
 /* TEST: QOUT( "at( 'cde', 'abcdefgfedcba' ) = '" + at( 'cde', 'abcsefgfedcba' ) + "'" ) */
 HARBOUR HB_AT( void )
diff --git a/harbour/source/vm/hvm.c b/harbour/source/vm/hvm.c
index e5d19e3eaa..e80294013e 100644
--- a/harbour/source/vm/hvm.c
+++ b/harbour/source/vm/hvm.c
@@ -1794,11 +1794,11 @@ static void hb_vmInstring( void )
    pItem2 = hb_stack.pPos - 1;
    if( IS_STRING( pItem1 ) && IS_STRING( pItem2 ) )
    {
-      int iResult = hb_strAt( pItem1->item.asString.value, pItem1->item.asString.length,
-                              pItem2->item.asString.value, pItem2->item.asString.length );
+      BOOL bResult = ( hb_strAt( pItem1->item.asString.value, pItem1->item.asString.length,
+                                 pItem2->item.asString.value, pItem2->item.asString.length ) != 0 );
       hb_stackPop();
       hb_stackPop();
-      hb_vmPushLogical( iResult == 0 ? FALSE : TRUE );
+      hb_vmPushLogical( bResult );
    }
    else if( IS_OBJECT( pItem1 ) && hb_objHasMsg( pItem1, "$" ) )
       hb_vmOperatorCall( pItem1, pItem2, "$" );