Fix [Bug 2130992].

2 files changed, 26 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index b45d8e5..19043f7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-09-27  Donal K. Fellows  <dkf@users.sf.net>
+
+	* generic/tclCmdIL.c (Tcl_LrepeatObjCmd): Improve the handling of the
+	case where the combination of number of elements and repeat count
+	causes the resulting list to be too large. [Bug 2130992]
+
 2008-09-26  Don Porter  <dgp@users.sourceforge.net>
 
 	TIP #323 IMPLEMENTATION (partial)
diff --git a/generic/tclCmdIL.c b/generic/tclCmdIL.c
index 99a6cb5..73144f8 100644
--- a/generic/tclCmdIL.c
+++ b/generic/tclCmdIL.c
@@ -16,7 +16,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclCmdIL.c,v 1.153 2008/09/26 21:05:57 dgp Exp $
+ * RCS: @(#) $Id: tclCmdIL.c,v 1.154 2008/09/27 14:16:42 dkf Exp $
  */
 
 #include "tclInt.h"
@@ -2443,7 +2443,7 @@ Tcl_LrepeatObjCmd(
     register Tcl_Obj *const objv[])
 				/* The argument objects. */
 {
-    int elementCount, i;
+    int elementCount, i, totalElems;
     Tcl_Obj *listPtr, **dataArray;
     List *listRepPtr;
 
@@ -2473,12 +2473,28 @@ Tcl_LrepeatObjCmd(
     objv += 2;
 
     /*
+     * Final sanity check. Total number of elements must fit in a signed
+     * integer. We also limit the number of elements to 512M-1 so allocations
+     * on 32-bit machines are guaranteed to be less than 2GB! [Bug 2130992]
+     */
+
+    totalElems = objc * elementCount;
+    if (totalElems/objc != elementCount || totalElems/elementCount != objc) {
+	Tcl_AppendResult(interp, "too many elements in result list", NULL);
+	return TCL_ERROR;
+    }
+    if (totalElems >= 0x20000000) {
+	Tcl_AppendResult(interp, "too many elements in result list", NULL);
+	return TCL_ERROR;
+    }
+
+    /*
      * Get an empty list object that is allocated large enough to hold each
      * init value elementCount times.
      */
 
-    listPtr = Tcl_NewListObj(elementCount*objc, NULL);
-    listRepPtr = (List *) listPtr->internalRep.twoPtrValue.ptr1;
+    listPtr = Tcl_NewListObj(totalElems, NULL);
+    listRepPtr = listPtr->internalRep.twoPtrValue.ptr1;
     listRepPtr->elemCount = elementCount*objc;
     dataArray = &listRepPtr->elements;