Item5121: Performance: Copy hash

I got this feedbakc via e-mail from Klaus Ethgen:

QUOTE

I found a little performance issue. You use sometimes sort to
copy one hash to another. For example line 493ff in TWiki/UI/Manage.pm:

        foreach my $ref (sort keys %$refs0) {
            $refs{$ref} = $refs0->{$ref};
        }
        foreach my $ref (sort keys %$refs1) {
            $refs{$ref} = $refs1->{$ref};
        }

This makes absolutely no sense as the sort order is irrelevant in both,
the target and the destination. So this only kills performance. A better
solution would be:

   %refs = (%$refs0, %$refs1);

/QUOTE

-- TWiki:Main/PeterThoeny - 12 Dec 2007

Perhaps a hangover from a time when that loop did an order-dependent operation. As far as I can see there is only one instance of this pattern in the code.

Changed in MAIN only (for Georgetown/next patch)

-- TWiki:Main.CrawfordCurrie - 13 Dec 2007

see Item5554 for merge to 4.2.x branch

-- TWiki:Main.SvenDowideit - 22 Apr 2008