From fbada465b441596587db58a5972e6acc516208f2 Mon Sep 17 00:00:00 2001 From: dkf Date: Sat, 27 Feb 2010 19:02:25 +0000 Subject: Only look for the needle when it fits in the haystack. [Bug 2960021] --- ChangeLog | 5 +++++ generic/tclCmdMZ.c | 16 +++++++++++++--- 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/ChangeLog b/ChangeLog index ce4e1aa..98c8360 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,10 @@ 2010-02-27 Donal K. Fellows + * generic/tclCmdMZ.c (StringFirstCmd, StringLastCmd): [Bug 2960021]: + Only search for the needle in the haystack when the needle isn't + larger than the haystack. Prevents an odd crash from sometimes + happening when things get mixed up (a common programming error). + * generic/tclMain.c (Tcl_Main): [Bug 801429]: Factor out the holding of the client-installed main loop function into thread-specific data. diff --git a/generic/tclCmdMZ.c b/generic/tclCmdMZ.c index 5ec25b3..af97570 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 1.201 2010/02/24 10:45:04 dkf Exp $ + * RCS: @(#) $Id: tclCmdMZ.c,v 1.202 2010/02/27 19:02:26 dkf Exp $ */ #include "tclInt.h" @@ -1208,7 +1208,12 @@ StringFirstCmd( } } - if (needleLen > 0) { + /* + * If the length of the needle is more than the length of the haystack, it + * cannot be contained in there so we can avoid searching. [Bug 2960021] + */ + + if (needleLen > 0 && needleLen <= haystackLen) { register Tcl_UniChar *p, *end; end = haystackStr + haystackLen - needleLen + 1; @@ -1313,7 +1318,12 @@ StringLastCmd( p = haystackStr + haystackLen - needleLen; } - if (needleLen > 0) { + /* + * If the length of the needle is more than the length of the haystack, it + * cannot be contained in there so we can avoid searching. [Bug 2960021] + */ + + if (needleLen > 0 && needleLen <= haystackLen) { for (; p >= haystackStr; p--) { /* * Scan backwards to find the first character. -- cgit v0.12