From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 26 Nov 2008 22:54:34 GMT
Subject: Re: [PATCH 1/2] Add / command in add --patch (feature request)
Message-ID: <7vod02cd3p.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <20081126223858.GB10786@coredump.intra.peff.net>

Jeff King <peff@peff.net> writes:

> On Wed, Nov 26, 2008 at 08:51:20PM +0000, William Pursell wrote:
>
>> This is naive, and it is easy for an invalid
>> search string to cause a perl error.
>> [...]
>> +			if( $text !~ $search_s ) {
>
> Yeah, a bad regex will cause the whole program to barf. Maybe wrap it in
> an eval, like this?
>
>   my $r = eval { $text !~ $search_s };
>   if ($@) {
>     print STDERR "error in search string: $@\n";
>     next;
>   }
>   if ($r) {
>     ...
>
> Or similar (I didn't look at the code closely enough to know if "next"
> is the right thing there).

Use of eval is a good way to protect against this kind of breakage, but it
should be done close to where the string is given by the user, perhaps in
here:


+			elsif ($line =~ m|^/(.*)|) {
+				$search_s = $1;
+			}

Something like...

	elsif ($line =~ m|^/(.*)|) {
        	$search_string = $1;
                eval {
                	$search_string =~ /$search_string/;
		};
                if ($@) {
                	print STDERR "Regexp error in $search_string: $@";
			next;
		}
	...