PHP - Setgid Bit Always Unset When Changing File Permissions - A Strange Bug

<?php
include("config.inc.php");

if ($_SERVER['REQUEST_METHOD'] == "POST") 
{

 include("config.inc.php");
    if(!$_POST) {
    header("Location: preexport.php");
    exit();
} 

 
    // initialization
    $result_final = "";
    $counter = 0;

// List of our known photo types
    $known_photo_types = array(
                        'image/pjpeg' => 'jpg',
                        'image/jpeg' => 'jpg',
                        'image/gif' => 'gif',
                        'image/bmp' => 'bmp',
                        'image/x-png' => 'png'
                    );
   
// GD Function List
    $gd_function_suffix = array(
                        'image/pjpeg' => 'JPEG',
                        'image/jpeg' => 'JPEG',
                        'image/gif' => 'GIF',
                        'image/bmp' => 'WBMP',
                        'image/x-png' => 'PNG'
                    );
 
// Fetch the photo array sent by preexport.php
    $photos_uploaded = $_FILES['photo_filename'];
    $filename[]= $photos_uploaded['name'][$counter];
	//print_r($photos_uploaded);
  $photo_caption = $_POST['photo_caption'];

// Fetch the photo caption array
    $photo_description = $_POST['photo_description'];

// Fetch the photo caption array
    $photo_keyword = $_POST['photo_keyword'];
     
    while( $counter <count($_FILES['photo_filename']['tmp_name']) ) 
{
        if($photos_uploaded['size'][$counter] > 0)
        {
            if(!array_key_exists($photos_uploaded['type'][$counter], $known_photo_types))
            {
                $result_final .= "File ".($counter+1)." is not a photo<br />";
            }
            else
            {
			
			/*print "HHHHHH\n";
			print "Counter is $counter : ";
			print $photos_uploaded['name'][0];
			print $photos_uploaded['name'][1];
			print "Photo caption is $photo_caption[$counter]"; */
                mysqli_query(
                    $mysqli,"INSERT INTO
                        gallery_photos (
                    `photo_filename`,
		    `photo_caption`,
                    `photo_description`,
		    `photo_keywords`,
                    `category_name`
                    ) VALUES(
		        '".addslashes($photos_uploaded['name'][$counter])."',
                        '".addslashes($photo_caption[$counter])."',
                        '".addslashes($photo_description[$counter])."',
                        '".addslashes($photo_keyword[$counter])."',
                        '".addslashes($_POST['category'])."')"
                    ) or die(mysqli_error() . 'Photo not uploaded');
                   
               // $new_id = mysqli_insert_id();
                $filetype = $photos_uploaded['type'][$counter];
				
                $extention = $known_photo_types[$filetype];
                //$filename = $photo_filename[$counter].".".$extention;
		//$filename = $new_id.".".$extention;
 
              //  mysqli_query( "UPDATE gallery_photos SET photo_filename='".addslashes($filename)."' WHERE photo_id='".addslashes($new_id)."'" );
 
                // Store the orignal file
				
                copy($photos_uploaded['tmp_name'][$counter], $images_dir."/".$photos_uploaded['name'][$counter]);
 
                // Let's get the Thumbnail size
                $size = GetImageSize( $images_dir."/".$photos_uploaded['name'][$counter] );
                if($size[0] > $size[1])
                {
                    $thumbnail_width = 200;
                    $thumbnail_height = (int)(200 * $size[1] / $size[0]);
                }
                else
                {
                    $thumbnail_width = (int)(200 * $size[0] / $size[1]);
                    $thumbnail_height = 200;
                }
           
                // Build Thumbnail with GD 1.x.x, you can use the other described methods too
                $function_suffix = $gd_function_suffix[$filetype];
                $function_to_read = "ImageCreateFrom".$function_suffix;
                $function_to_write = "Image".$function_suffix;
 
                // Read the source file
                $source_handle = $function_to_read ( $images_dir."/".$photos_uploaded['name'][$counter] );
				
				$sharpenMatrix = array
                (
                    array(-1.2, -1, -1.2),
                    array(-1, 8, -1),
                    array(-1.2, -1, -1.2)
                );
 
                // calculate the sharpen divisor
                $divisor = array_sum(array_map('array_sum', $sharpenMatrix));          
 
                $offset = 0;
               
                if($source_handle)
                {
                    // Let's create an blank image for the thumbnail
                        $destination_handle = ImageCreateTrueColor ( $thumbnail_width, $thumbnail_height );
               
                    // Now we resize it
                    ImageCopyResized( $destination_handle, $source_handle, 0, 0, 0, 0, $thumbnail_width, $thumbnail_height, $size[0], $size[1] );
                }
 
                // Let's save the thumbnail
                $function_to_write( $destination_handle, $images_dir."/tb_".$photos_uploaded['name'][$counter], 100 );
                ImageDestroy($destination_handle );
                //

           
               
 
                $result_final .= "<img src='".$images_dir. "/tb_".$photos_uploaded['name'][$counter]."' /> File ".($counter+1)." Added<br />";
            }
        }
    $counter++;
    }
 
    // Print Result
echo <<<__HTML_END
 
<html>
<head>
    <title>Photos uploaded</title>
</head>
<body>
    $result_final
</body>
</html>
 
__HTML_END;

}
?>

<?php
 include 'config.inc.php';
 
  $photo_category_list = '';
 $photo_upload_fields = '';
 $counter = 1;
 
 // If we want more fields, then use, preexport.php?number_of_fields=9
 $number_of_fields = (isset($_GET['number_of_fields'])) ?
   (int)($_GET['number_of_fields']) : 9;
 
 // Firstly Lets build the Category List
 $result = mysqli_query($mysqli,'SELECT category_name FROM gallery_category');
 /*if($result === FALSE) {
    die(mysqli_error()); // TODO: better error handling
}*/
 while($row = mysqli_fetch_array($result)) {
   $photo_category_list .= <<<__HTML_END
<option value="$row[0]">$row[0]</option>\n
__HTML_END;
 }
 mysqli_free_result( $result ); 
 
 // Lets build the Image Uploading fields
 while($counter <= $number_of_fields) {
   $photo_upload_fields .= <<<__HTML_END
<tr><td>
 Photo {$counter}:
 <input name="photo_filename[]"
type="file" />
</td></tr>
<tr><td>
 Caption:
 <textarea name="photo_caption[]" cols="50"
   rows="1"></textarea>
</td></tr>
<tr><td>
 Description:
 <textarea name="photo_description[]" cols="50"
   rows="4"></textarea>
</td></tr>
<tr><td>
 Keyword:
 <textarea name="photo_keyword[]" cols="50"
   rows="4"></textarea>
</td></tr>
__HTML_END;
   $counter++;
 }
 
 // Final Output
 echo <<<__HTML_END
<html>
<head>
<title> Rajeev lets upload photos!! </title>
</head>
<body>
<form enctype="multipart/form-data"
 action="export.php" method="post"
 name="export_form">
 <table width="90%" border="0"
   align="center" style="width: 90%;">
   <tr><td>
     Select Category
     <select name="category">
     $photo_category_list
     </select>
   </td></tr>
   <!&#8212;Insert the image fields here -->
   $photo_upload_fields
   <tr><td>
     <input type="submit" name="submit"
       value="Add Photos" />
   </td></tr>
 </table>
</form>
</body>
</html>
__HTML_END;
?>

- uniperms_nodes

- key (Int, Not Null, Primary Key, Auto Increment)
- type (Enum('USER', 'GROUP'), Not Null)
- id (Int, Not Null)
- permission (Varchar(255), Not Null)
- description (Text)

INSERT INTO `uniperms_nodes` (`type`, `id`, `permission`, `description`) 
VALUES ('GROUP', '1', 'my.test.node', 'A simple permission');

SELECT `permission` FROM `uniperms_nodes`
WHERE type='GROUP' AND id=1;