Index: lib/TWiki/Store/RcsFile.pm
===================================================================
--- lib/TWiki/Store/RcsFile.pm	(revision 12498)
+++ lib/TWiki/Store/RcsFile.pm	(working copy)
@@ -328,43 +328,63 @@
     my( $this, $searchString, $topics, $options ) = @_;
     ASSERT(defined $options) if DEBUG;
     my $type = $options->{type} || '';
-
-    # I18N: 'grep' must use locales if needed,
-    # for case-insensitive searching.  See TWiki::setupLocale.
-    my $program = '';
-    # FIXME: For Cygwin grep, do something about -E and -F switches
-    # - best to strip off any switches after first space in
-    # EgrepCmd etc and apply those as argument 1.
-    if( $type eq 'regex' ) {
-        $program = $TWiki::cfg{RCS}{EgrepCmd};
-    } else {
-        $program = $TWiki::cfg{RCS}{FgrepCmd};
-    }
-
-    $program =~ s/%CS{(.*?)\|(.*?)}%/$options->{casesensitive}?$1:$2/ge;
-    $program =~ s/%DET{(.*?)\|(.*?)}%/$options->{files_without_match}?$2:$1/ge;
-
     my $sDir = $TWiki::cfg{DataDir}.'/'.$this->{web}.'/';
-    my $seen = {};
-    # process topics in sets, fix for Codev.ArgumentListIsTooLongForSearch
-    my $maxTopicsInSet = 512; # max number of topics for a grep call
-    my @take = @$topics;
-    my @set = splice( @take, 0, $maxTopicsInSet );
-    my $sandbox = $this->{session}->{sandbox};
-    while( @set ) {
-        @set = map { "$sDir/$_.txt" } @set;
-        my ($matches, $exit ) = $sandbox->sysCommand(
-            $program,
-            TOKEN => $searchString,
-            FILES => \@set);
-        foreach my $match ( split( /\r?\n/, $matches )) {
-            if( $match =~ m/([^\/]*)\.txt(:(.*))?$/ ) {
-                push( @{$seen->{$1}}, $3 );
+    my $matches = '';
+    my %seen;
+    if (exists $ENV{MOD_PERL}) {
+        # Use pure-perl grep if MOD_PERL, as the fork() used by TWiki::Sandbox
+        # is horribly inefficient with mod_perl
+        local $/ = "\n";
+        if ($type eq 'regex') {
+            $searchString =~ s!/!\\/!g;
+        } else {
+            $searchString =~ s/(\W)/\\$1/g;
+        }
+        my $match_code = "/$searchString/o";
+        $match_code .= 'i' unless ($options->{casesensitive});
+        my $doMatch = eval "sub { $match_code }";
+      FILE:
+        foreach my $file ( @$topics ) {
+            next unless open(FILE, "$sDir/$file.txt");
+            while (<FILE>) {
+                if (&$doMatch()) {
+                    push( @{$seen{$file}}, $_ );
+                    next FILE if $options->{files_without_match};
+                }
             }
         }
-        @set = splice( @take, 0, $maxTopicsInSet );
+    } else {
+        # I18N: 'grep' must use locales if needed,
+        # for case-insensitive searching.  See TWiki::setupLocale.
+        my $program = '';
+        # FIXME: For Cygwin grep, do something about -E and -F switches
+        # - best to strip off any switches after first space in
+        # EgrepCmd etc and apply those as argument 1.
+        if( $type eq 'regex' ) {
+            $program = $TWiki::cfg{RCS}{EgrepCmd};
+        } else {
+            $program = $TWiki::cfg{RCS}{FgrepCmd};
+        }
+
+        $program =~ s/%CS{(.*?)\|(.*?)}%/$options->{casesensitive}?$1:$2/ge;
+        $program =~ s/%DET{(.*?)\|(.*?)}%/$options->{files_without_match}?$2:$1/ge;
+        # process topics in sets, fix for Codev.ArgumentListIsTooLongForSearch
+        my $maxTopicsInSet = 512; # max number of topics for a grep call
+        my @take = @$topics;
+        my @set = splice( @take, 0, $maxTopicsInSet );
+        my $sandbox = $this->{session}->{sandbox};
+        while( @set ) {
+            @set = map { "$sDir/$_.txt" } @set;
+            my ($m, $exit ) = $sandbox->sysCommand(
+                $program,
+                TOKEN => $searchString,
+                FILES => \@set);
+            $matches .= $m;
+            @set = splice( @take, 0, $maxTopicsInSet );
+        }
+        $matches =~ s/([^\/]*)\.txt(:(.*))?$/push( @{$seen{$1}}, $3 ); ''/gem;
     }
-    return $seen;
+    return \%seen;
 }
 
 =pod