From 401efde7b4d67a1ca4b84373795ec67ccd785306 Mon Sep 17 00:00:00 2001
From: Kevin B Kenny <kennykb@acm.org>
Date: Mon, 23 Apr 2007 17:34:05 +0000
Subject: * generic/tclEnv.c (ReplaceString): Clear memory correctly when
 growing the cache to avoid reads of uninitialised data. * generic/tclStrToD.c
 (AccumulateDecimalDigit): Fixed a mistake where we'd run beyond the end of
 the 'pow10_wide' array if a number begins with a string of more than
 'maxpow10_wide' zeroes. Both these issues reported under [Bug 1705778] -
 detected with the existing test suite, no new regression tests required.

---
 ChangeLog           | 10 ++++++++++
 generic/tclEnv.c    |  5 +++--
 generic/tclStrToD.c | 48 +++++++++++++++++++++++++++++-------------------
 3 files changed, 42 insertions(+), 21 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 34a0c00..0830cc4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2007-04-23  Kevin B. Kenny  <kennykb@acm.org>
+
+	* generic/tclEnv.c (ReplaceString): Clear memory correctly when
+	growing the cache to avoid reads of uninitialised data.
+	* generic/tclStrToD.c (AccumulateDecimalDigit): Fixed a mistake
+	where we'd run beyond the end of the 'pow10_wide' array if
+	a number begins with a string of more than 'maxpow10_wide' zeroes.
+	Both these issues reported under [Bug 1705778] - detected with
+	the existing test suite, no new regression tests required.
+	
 2007-04-22  Miguel Sofer  <msofer@users.sf.net>
 
 	* generic/tclVar.c (TclDeleteNamespaceVars): fixed access to freed
diff --git a/generic/tclEnv.c b/generic/tclEnv.c
index 596e68b..30bce65 100644
--- a/generic/tclEnv.c
+++ b/generic/tclEnv.c
@@ -12,7 +12,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclEnv.c,v 1.32 2007/04/10 14:47:13 dkf Exp $
+ * RCS: @(#) $Id: tclEnv.c,v 1.33 2007/04/23 17:34:06 kennykb Exp $
  */
 
 #include "tclInt.h"
@@ -677,7 +677,8 @@ ReplaceString(
 	environCache = (char **) ckrealloc ((char *) environCache, 
 		(cacheSize + growth) * sizeof(char *));
 	environCache[cacheSize] = newStr;
-	(void) memset(environCache+cacheSize+1, (int) 0, (size_t) (growth - 1));
+	(void) memset(environCache+cacheSize+1, (int) 0,
+		      (size_t) ((growth-1) * sizeof(char*)));
 	cacheSize += growth;
     }
 }
diff --git a/generic/tclStrToD.c b/generic/tclStrToD.c
index afcf7eb..dc19855 100755
--- a/generic/tclStrToD.c
+++ b/generic/tclStrToD.c
@@ -14,7 +14,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclStrToD.c,v 1.29 2007/04/16 13:36:35 dkf Exp $
+ * RCS: @(#) $Id: tclStrToD.c,v 1.30 2007/04/23 17:34:07 kennykb Exp $
  *
  *----------------------------------------------------------------------
  */
@@ -1182,32 +1182,42 @@ AccumulateDecimalDigit(
 				 * to this digit. */
 {
     int i, n;
+    Tcl_WideUInt w;
 
     /*
-     * Check if the number still fits in a wide.
+     * Try wide multiplication first
      */
 
-    if (!bignumFlag && *wideRepPtr!=0 && ((numZeros >= maxpow10_wide) ||
-	    *wideRepPtr > ((~(Tcl_WideUInt)0)-digit)/pow10_wide[numZeros+1])) {
-	/*
-	 * Oops, it's overflowed, have to allocate a bignum.
-	 */
-
-	TclBNInitBignumFromWideUInt (bignumRepPtr, *wideRepPtr);
-	bignumFlag = 1;
+    if (!bignumFlag) {
+	w = *wideRepPtr;
+	if (w == 0) {
+	    /*
+	     * There's no need to multiply if the multiplicand is zero.
+	     */
+	    *wideRepPtr = digit;
+	    return 0;
+	} else if (numZeros >= maxpow10_wide
+		  || w > ((~(Tcl_WideUInt)0)-digit)/pow10_wide[numZeros+1]) {
+	    /*
+	     * Wide multiplication will overflow.  Expand the
+	     * number to a bignum and fall through into the bignum case.
+	     */
+	    
+	    TclBNInitBignumFromWideUInt (bignumRepPtr, w);
+	} else {
+	    /*
+	     * Wide multiplication.
+	     */
+	    *wideRepPtr = w * pow10_wide[numZeros+1] + digit;
+	    return 0;
+	}
     }
 
     /*
-     * Multiply the number by 10**numZeros+1 and add in the new digit.
+     * Bignum multiplication.
      */
 
-    if (!bignumFlag) {
-	/*
-	 * Wide multiplication.
-	 */
-
-	*wideRepPtr = *wideRepPtr * pow10_wide[numZeros+1] + digit;
-    } else if (numZeros < log10_DIGIT_MAX) {
+    if (numZeros < log10_DIGIT_MAX) {
 	/*
 	 * Up to about 8 zeros - single digit multiplication.
 	 */
@@ -1240,7 +1250,7 @@ AccumulateDecimalDigit(
 	mp_add_d(bignumRepPtr, (mp_digit) digit, bignumRepPtr);
     }
 
-    return bignumFlag;
+    return 1;
 }
 
 /*
-- 
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