Index: branches/5.0.x/core/units/helpers/image_helper.php
===================================================================
diff -u -r12322 -r12324
--- branches/5.0.x/core/units/helpers/image_helper.php	(.../image_helper.php)	(revision 12322)
+++ branches/5.0.x/core/units/helpers/image_helper.php	(.../image_helper.php)	(revision 12324)
@@ -1,6 +1,6 @@
 <?php
 /**
-* @version	$Id: image_helper.php 12322 2009-08-17 10:41:40Z alex $
+* @version	$Id: image_helper.php 12324 2009-08-17 21:50:09Z alex $
 * @package	In-Portal
 * @copyright	Copyright (C) 1997 - 2009 Intechnic. All rights reserved.
 * @license      GNU/GPL
@@ -164,10 +164,9 @@
 
 					$dst_image_rs = imagecreatetruecolor($params['target_width'], $params['target_height']); // resize target size
 
-					if ($file_extension == 'png') {
-						// preserve transparency of PNG images
-						$transparent_color = imagecolorallocate($dst_image_rs, 0, 0, 0);
-						imagecolortransparent($dst_image_rs, $transparent_color);
+					if (($file_extension == 'gif') || ($file_extension == 'png')) {
+						// preserve transparency of PNG and GIF images
+						$dst_image_rs = $this->_preserveTransparency($src_image_rs, $dst_image_rs, $image_info[2]);
 					}
 
 					// 1. resize
@@ -202,6 +201,53 @@
 		}
 
 		/**
+		 * Preserve transparency for GIF and PNG images
+		 *
+		 * @param resource $src_image_rs
+		 * @param resource $dst_image_rs
+		 * @param int $image_type
+		 * @return resource
+		 */
+		function _preserveTransparency($src_image_rs, $dst_image_rs, $image_type)
+		{
+			$transparent_index = imagecolortransparent($src_image_rs);
+
+			// if we have a specific transparent color
+			if ($transparent_index >= 0) {
+				// get the original image's transparent color's RGB values
+				$transparent_color = imagecolorsforindex($src_image_rs, $transparent_index);
+
+				// allocate the same color in the new image resource
+				$transparent_index = imagecolorallocate($dst_image_rs, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);
+
+				// completely fill the background of the new image with allocated color
+				imagefill($dst_image_rs, 0, 0, $transparent_index);
+
+				// set the background color for new image to transparent
+				imagecolortransparent($dst_image_rs, $transparent_index);
+
+				return $dst_image_rs;
+			}
+
+			// always make a transparent background color for PNGs that don't have one allocated already
+			if ($image_type == IMAGETYPE_PNG) {
+				// turn off transparency blending (temporarily)
+				imagealphablending($dst_image_rs, false);
+
+				// create a new transparent color for image
+				$transparent_color = imagecolorallocatealpha($dst_image_rs, 0, 0, 0, 127);
+
+				// completely fill the background of the new image with allocated color
+				imagefill($dst_image_rs, 0, 0, $transparent_color);
+
+				// restore transparency blending
+				imagesavealpha($dst_image_rs, true);
+			}
+
+			return $dst_image_rs;
+		}
+
+		/**
 		 * Fills margins (if any) of resized are with given color
 		 *
 		 * @param resource $src_image_rs resized image resource