--- rxvt-unicode/src/perl/background	2012/06/14 17:06:57	1.56
+++ rxvt-unicode/src/perl/background	2012/06/15 19:50:56	1.61
@@ -287,7 +287,7 @@
    sub solid($;$$) {
       my $colour = pop;
 
-      my $img = $self->new_img (urxvt::PictStandardARGB32, $_[0] || 1, $_[1] || 1);
+      my $img = $self->new_img (urxvt::PictStandardARGB32, 0, 0, $_[0] || 1, $_[1] || 1);
       $img->fill ($colour);
       $img
    }
@@ -305,12 +305,44 @@
 
 =item merge $img ...
 
-Takes any number of images and merges them together, creating a single image containing them all.
+Takes any number of images and merges them together, creating a single
+image containing them all.
+
+This function is called automatically when an expression returns multiple
+images.
 
 =cut
 
    sub merge(@) {
-      #TODO
+      return $_[0] unless $#_;
+
+      # rather annoyingly clumsy, but optimisation is for another time
+
+      my $x0 = +1e9;
+      my $y0 = +1e9;
+      my $x1 = -1e9;
+      my $y1 = -1e9;
+
+      for (@_) {
+         my ($x, $y, $w, $h) = $_->geometry;
+
+         $x0 = $x if $x0 > $x;
+         $y0 = $y if $y0 > $y;
+
+         $x += $w;
+         $y += $h;
+
+         $x1 = $x if $x1 < $x;
+         $y1 = $y if $y1 < $y;
+      }
+
+      my $base = $self->new_img (urxvt::PictStandardARGB32, $x0, $y0, $x1 - $x0, $y1 - $y0);
+      $base->fill ([0, 0, 0, 0]);
+
+      $base->draw ($_)
+         for @_;
+
+      $base
    }
 
 =head2 TILING MODES
@@ -672,8 +704,8 @@
    sub rotate($$$$) {
       my $img = pop;
       $img->rotate (
-         $_[0] * $img->w,
-         $_[1] * $img->h,
+         $_[0] * ($img->w + $img->x),
+         $_[1] * ($img->h + $img->y),
          $_[2] * (3.14159265 / 180),
       )
    }
@@ -880,8 +912,8 @@
 
    # evaluate user expression
 
-   my $img = eval { $self->{expr}->() };
-   warn $@ if $@;#d#
+   my $img = eval { urxvt::bgdsl::merge $self->{expr}->() };
+   die $@ if $@;
    die "background-expr did not return an image.\n" if !UNIVERSAL::isa $img, "urxvt::img";
 
    # if the expression is sensitive to external events, prepare reevaluation then