* generic/tclCmdMZ.c: Revised [string to* $s $first $last]

        implementation to reduce number of allocs/copies.

2 files changed, 7 insertions, 8 deletions

diff --git a/ChangeLog b/ChangeLog
index 0208fd7..b741156 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2007-03-30  Don Porter  <dgp@users.sourceforge.net>
 
+	* generic/tclCmdMZ.c:	Revised [string to* $s $first $last]
+	implementation to reduce number of allocs/copies.
+
 	* tests/string.test:  More [string reverse] tests.
 
 2007-03-30  Miguel Sofer  <msofer@users.sf.net>
diff --git a/generic/tclCmdMZ.c b/generic/tclCmdMZ.c
index 4d82870..67659c1 100644
--- a/generic/tclCmdMZ.c
+++ b/generic/tclCmdMZ.c
@@ -15,7 +15,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclCmdMZ.c,v 1.146 2007/03/28 19:03:42 dgp Exp $
+ * RCS: @(#) $Id: tclCmdMZ.c,v 1.147 2007/03/30 15:54:17 dgp Exp $
  */
 
 #include "tclInt.h"
@@ -2303,10 +2303,8 @@ Tcl_StringObjCmd(
 
 	    start = Tcl_UtfAtIndex(string1, first);
 	    end = Tcl_UtfAtIndex(start, last - first + 1);
-	    length2 = end-start;
-	    string2 = ckalloc((size_t) length2+1);
-	    memcpy(string2, start, (size_t) length2);
-	    string2[length2] = '\0';
+	    resultPtr = Tcl_NewStringObj(string1, end - string1);
+	    string2 = Tcl_GetString(resultPtr) + (start - string1);
 
 	    if ((enum options) index == STR_TOLOWER) {
 		length2 = Tcl_UtfToLower(string2);
@@ -2315,12 +2313,10 @@ Tcl_StringObjCmd(
 	    } else {
 		length2 = Tcl_UtfToTitle(string2);
 	    }
+	    Tcl_SetObjLength(resultPtr, length2 + (start - string1));
 
-	    resultPtr = Tcl_NewStringObj(string1, start - string1);
-	    Tcl_AppendToObj(resultPtr, string2, length2);
 	    Tcl_AppendToObj(resultPtr, end, -1);
 	    Tcl_SetObjResult(interp, resultPtr);
-	    ckfree(string2);
 	}
 	break;