From 595bfd1484ecc8212d6c3c028210b4d1ae78baba Mon Sep 17 00:00:00 2001
From: Derek Jones <derek.jones@ellislab.com>
Date: Fri, 20 Aug 2010 10:28:22 -0500
Subject: Added ability in the Image Library to handle PNG transparency for
 resize operations when using the GD lib.

---
 system/libraries/Image_lib.php | 7 +++++++
 user_guide/changelog.html      | 1 +
 2 files changed, 8 insertions(+)

diff --git a/system/libraries/Image_lib.php b/system/libraries/Image_lib.php
index 21e0a709b..806d942ba 100644
--- a/system/libraries/Image_lib.php
+++ b/system/libraries/Image_lib.php
@@ -513,6 +513,13 @@ class CI_Image_lib {
 		}
 
 		$dst_img = $create($this->width, $this->height);
+
+		if ($this->image_type == 3) // png we can actually preserve transparency
+		{
+			imagealphablending($dst_img, FALSE);
+			imagesavealpha($dst_img, TRUE);
+		}
+		
 		$copy($dst_img, $src_img, 0, 0, $this->x_axis, $this->y_axis, $this->width, $this->height, $this->orig_width, $this->orig_height);
 
 		//  Show the image
diff --git a/user_guide/changelog.html b/user_guide/changelog.html
index 171392f46..48d4309a5 100644
--- a/user_guide/changelog.html
+++ b/user_guide/changelog.html
@@ -98,6 +98,7 @@ Hg Tag: </p>
 			<li>Changed <kbd>do_xss_clean()</kbd> to return FALSE if the uploaded file fails XSS checks.</li> 
 			<li>Added stripslashes() and trim()ing of double quotes from $_FILES type value to standardize input in Upload library.</li>
 			<li>Added a second parameter (boolean) to <kbd>$this->zip->read_dir('/path/to/directory', FALSE)</kbd> to remove the preceding trail of empty folders when creating a Zip archive. This example would contain a zip with "directory" and all of its contents.</li>
+			<li>Added ability in the Image Library to handle PNG transparency for resize operations when using the GD lib.</p>
 		</ul>
 	</li>
 	<li>Database
-- 
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