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  // PHP 5.5 GD bug: https://bugs.php.net/bug.php?id=65148: To prevent buggy

  // behavior on negative multiples of 90 degrees we convert any negative

  // angle to a positive one between 0 and 360 degrees.

  $degrees -= floor($degrees / 360) * 360;

  // Convert the hexadecimal background value to a RGBA array.

    $background = array(

      'red' => $background >> 16 & 0xFF,

      'green' => $background >> 8 & 0xFF,

      'blue' => $background & 0xFF,

      'alpha' => 0,

    );

    // Background color is not specified: use transparent white as background.

    $background = array(

      'red' => 255,

      'green' => 255,

      'blue' => 255,

      'alpha' => 127

    );

  // Store the color index for the background as that is what GD uses.

  $background_idx = imagecolorallocatealpha($image->resource, $background['red'], $background['green'], $background['blue'], $background['alpha']);

    // GIF does not work with a transparency channel, but can define 1 color

    // in its palette to act as transparent.

    // Get the current transparent color, if any.

    $gif_transparent_id = imagecolortransparent($image->resource);

    if ($gif_transparent_id !== -1) {

      // The gif already has a transparent color set: remember it to set it on

      // the rotated image as well.

      $transparent_gif_color = imagecolorsforindex($image->resource, $gif_transparent_id);

      if ($background['alpha'] >= 127) {

        // We want a transparent background: use the color already set to act

        // as transparent, as background.

        $background_idx = $gif_transparent_id;

      }

    }

    else {

      // The gif does not currently have a transparent color set.

      if ($background['alpha'] >= 127) {

        // But as the background is transparent, it should get one.

        $transparent_gif_color = $background;

      }

  $image->resource = imagerotate($image->resource, 360 - $degrees, $background_idx);