Index: src/vdbe.c
==================================================================
--- src/vdbe.c
+++ src/vdbe.c
@@ -41,11 +41,11 @@
 ** documentation, headers files, or other derived files.  The formatting
 ** of the code in this file is, therefore, important.  See other comments
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 **
-** $Id: vdbe.c,v 1.622 2007/05/17 16:38:30 danielk1977 Exp $
+** $Id: vdbe.c,v 1.623 2007/05/23 06:31:39 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
 #include <ctype.h>
 #include <math.h>
@@ -1031,10 +1031,11 @@
     assert( pOp->p2==0 || (pTerm->flags&MEM_Str) );
     if( pTerm->flags&MEM_Null ){
       nByte = -1;
       break;
     }
+    ExpandBlob(pTerm);
     Stringify(pTerm, encoding);
     nByte += pTerm->n;
   }
 
   if( nByte<0 ){

Index: test/zeroblob.test
==================================================================
--- test/zeroblob.test
+++ test/zeroblob.test
@@ -11,11 +11,11 @@
 # This file implements regression tests for SQLite library.  The
 # focus of this file is testing of the zero-filled blob functionality
 # including the sqlite3_bind_zeroblob(), sqlite3_result_zeroblob(),
 # and the built-in zeroblob() SQL function.
 #
-# $Id: zeroblob.test,v 1.3 2007/05/17 06:44:29 danielk1977 Exp $
+# $Id: zeroblob.test,v 1.4 2007/05/23 06:31:39 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
 
 ifcapable !incrblob {
@@ -117,8 +117,16 @@
       UNION ALL
       SELECT zeroblob(10) AS a
     )
   }
 } {1}
+
+# Concatentation works with zeroblob
+#
+do_test zeroblob-4.1 {
+  execsql {
+    SELECT hex(zeroblob(2) || x'61')
+  }
+} {000061}
   
 
 finish_test