* generic/tclStringObj.c (Tcl_AppendFormatToObj): Correct failure to

        * tests/format.test:    account for big.used == 0 corner case in the
        %ll(idox) format directives.  [Bug 1867855].

3 files changed, 15 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index 61eb727..532cd00 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-01-10  Don Porter	<dgp@users.sourceforge.net>
+
+	* generic/tclStringObj.c (Tcl_AppendFormatToObj):  Correct failure to
+	* tests/format.test:	account for big.used == 0 corner case in the
+	%ll(idox) format directives.  [Bug 1867855].
+
 2008-01-09  George Peter Staplin <georgeps@xmission.com>
 
 	* doc/vwait.n: add a missing be to fix a typo.
diff --git a/generic/tclStringObj.c b/generic/tclStringObj.c
index 1b39745..57b1669 100644
--- a/generic/tclStringObj.c
+++ b/generic/tclStringObj.c
@@ -33,7 +33,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclStringObj.c,v 1.68 2007/12/13 15:23:20 dgp Exp $ */
+ * RCS: @(#) $Id: tclStringObj.c,v 1.69 2008/01/10 16:09:23 dgp Exp $ */
 
 #include "tclInt.h"
 #include "tommath.h"
@@ -2105,7 +2105,7 @@ Tcl_AppendFormatToObj(
 			numDigits++;
 			uw /= base;
 		    }
-		} else if (useBig) {
+		} else if (useBig && big.used) {
 		    int leftover = (big.used * DIGIT_BIT) % numBits;
 		    mp_digit mask = (~(mp_digit)0) << (DIGIT_BIT-leftover);
 
@@ -2114,7 +2114,7 @@ Tcl_AppendFormatToObj(
 			numDigits--;
 			mask >>= numBits;
 		    }
-		} else {
+		} else if (!useBig) {
 		    unsigned long int ul = (unsigned long int) l;
 
 		    bits = (Tcl_WideUInt) ul;
@@ -2138,7 +2138,7 @@ Tcl_AppendFormatToObj(
 		while (numDigits--) {
 		    int digitOffset;
 
-		    if (useBig) {
+		    if (useBig && big.used) {
 			if ((size_t) shift <
 				CHAR_BIT*sizeof(Tcl_WideUInt) - DIGIT_BIT) {
 			    bits |= (((Tcl_WideUInt)big.dp[index++]) <<shift);
diff --git a/tests/format.test b/tests/format.test
index 321f52f..b050fc3 100644
--- a/tests/format.test
+++ b/tests/format.test
@@ -10,7 +10,7 @@
 # See the file "license.terms" for information on usage and redistribution
 # of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 #
-# RCS: @(#) $Id: format.test,v 1.24 2006/03/21 11:12:29 dkf Exp $
+# RCS: @(#) $Id: format.test,v 1.25 2008/01/10 16:09:23 dgp Exp $
 
 if {[lsearch [namespace children] ::tcltest] == -1} {
     package require tcltest 2
@@ -553,6 +553,10 @@ test format-19.1 {
     list [expr { ~ $x }] [format %08x [expr { ~$x }]]
 } -match regexp -result {-2414724693 f*701239ab}
 
+test format-19.2 {Bug 1867855} {
+    format %llx 0
+} 0
+
 # cleanup
 catch {unset a}
 catch {unset b}