Changes have been made in Git for this ticket:

Don't assume the gallery will always have images.
Bug: 9200

http://git.horde.org/diff.php/ansel/lib/ImageGenerator.php?rt=horde-git&r1=c6f86a76f9ed9d8ec7f13c25c9ffff34ab5abce9&r2=0f1c2d6ba8ae5cab8ef74aa1548359db895948eb

( ! ) Fatal error: Call to a member function load() on a non-object in 
/home/jan/horde-git/ansel/lib/ImageGenerator.php on line 183
Call Stack
#        Time        Memory        Function        Location
1        0,0004        350156        {main}( )        ../view.php:0
2        2,1323        28625796        Ansel_View_List->html( )        ../view.php:50
3        2,1763        28825564        include( 
'/home/jan/horde-git/ansel/templates/view/list.inc' )        ../List.php:249
4        2,2272        28914576        Ansel_Gallery->getTile( NULL, 'ansel_polaroid', 
FALSE, array ('page' => 0, 'sort' => NULL, 'sort_dir' => 0, 'year' => 
0, 'month' => 0, 'day' => 0, 'view' => 'List', 'gallery_view' => NULL, 
'gallery_id' => NULL, 'gallery_slug' => NULL, 'force_grouping' => 
NULL, 'image_id' => NULL, '_pagerurl' => class Horde_Url { public $url 
= '/headhorde/ansel/user/jan/'; public $raw = FALSE; public 
$parameters = array (); public $pathInfo = NULL; public $anchor = ''; 
public $toStringCallback = NULL }, '_pager' => class 
Horde_Core_Ui_Pager { protected $_preserve = array ('sort_dir' => 0, 
'sort' => 'name'); protected $_name = 'page'; protected $_vars = class 
Horde_Variables { protected $_vars = array (...); protected 
$_expectedVariables = array (...); protected $_sanitized = FALSE }; 
protected $_config = array ('page_limit' => 10, 'perpage' => '9', 
'num' => '2', 'url' => class Horde_Url { ... }); protected 
$_url_callback = array (0 => 'Horde', 1 => 'applicationUrl') }) 
)        ../list.inc:46
5        2,2273        28915212        Ansel_Tile_Gallery->getTile( class Ansel_Gallery { 
protected $_modeHelper = class Ansel_GalleryMode_Date { protected 
$_date = array (); protected $_features = array (0 => 'slideshow', 1 
=> 'zipdownload', 2 => 'upload'); protected $_subGalleries = array (); 
protected $_gallery = ... }; public $data = array ('share_id' => 
'4852', 'share_owner' => 'jan', 'share_parents' => NULL, 'share_flags' 
=> '0', 'attribute_name' => 'Test', 'attribute_desc' => '', 
'attribute_default' => '139', 'attribute_default_type' => 'auto', 
'attribute_default_prettythumb' => '', 'attribute_style' => 
'ansel_sharpshadowed', 'attribute_category' => '', 
'attribute_last_modified' => '1216209754', 'attribute_date_created' => 
'1094397712', 'attribute_images' => '4', 'attribute_has_subgalleries' 
=> '0', 'attribute_slug' => '', 'attribute_age' => '0', 
'attribute_download' => 'all', 'attribute_passwd' => NULL, 
'attribute_view_mode' => 'Date', 'perm' => array ('type' => 'matrix', 
'default' => 6, 'guest' => 6, 'creator' => 0)); protected $_shareOb = 
class Horde_Share_Sql_Hierarchical { protected $_shareObject = 
'Ansel_Gallery'; protected $_db = class MDB2_Driver_mysql { public 
$string_quoting = array (...); public $identifier_quoting = array 
(...); public $sql_comments = array (...); public $start_transaction = 
TRUE; public $varchar_max_length = 65532; public $db_index = 2; public 
$dsn = array (...); public $connected_dsn = array (...); public 
$connection = resource(138) of type (mysql link); public 
$opened_persistent = FALSE; public $database_name = 'horde'; public 
$connected_database_name = 'horde'; public $connected_server_info = 
'5.0.51a'; public $supported = array (...); public $options = array 
(...); public $wildcards = array (...); public $as_keyword = ' AS '; 
public $warnings = array (...); public $debug_output = ''; public 
$in_transaction = NULL; public $nested_transaction_counter = NULL; 
public $has_transaction_error = FALSE; public $offset = 0; public 
$limit = 0; public $phptype = 'mysql'; public $dbsyntax = 'mysql'; 
public $last_query = 'SELECT DISTINCT s.* FROM ansel_shares s LEFT 
JOIN ansel_shares_users u ON u.share_id = s.share_id LEFT JOIN 
ansel_shares_groups g ON g.share_id = s.share_id WHERE (s.share_owner 
= \'jan\' OR (s.perm_creator & 2) OR (s.perm_default & 2) OR ( 
u.user_uid = \'jan\' AND (u.perm & 2)) OR (g.group_uid IN (\'8280\') 
AND (g.perm & 2))) AND (share_parents = \':4852\' OR share_parents 
LIKE \':4852:%\') ORDER BY s.share_id ASC'; public $fetchmode = 1; 
public $modules = array (...); public $destructor_registered = TRUE; 
public $_debug = FALSE; public $_default_error_mode = NULL; public 
$_default_error_options = NULL; public $_default_error_handler = ''; 
public $_error_class = 'PEAR_Error'; public $_expected_errors = array 
(...); public $datatype = class MDB2_Driver_Datatype_mysql { ... }; 
public $loaded_version_modules = array (...) }; protected $_write_db = 
class MDB2_Driver_mysql { public $string_quoting = array (...); public 
$identifier_quoting = array (...); public $sql_comments = array (...); 
public $start_transaction = TRUE; public $varchar_max_length = 65532; 
public $db_index = 2; public $dsn = array (...); public $connected_dsn 
= array (...); public $connection = resource(138) of type (mysql 
link); public $opened_persistent = FALSE; public $database_name = 
'horde'; public $connected_database_name = 'horde'; public 
$connected_server_info = '5.0.51a'; public $supported = array (...); 
public $options = array (...); public $wildcards = array (...); public 
$as_keyword = ' AS '; public $warnings = array (...); public 
$debug_output = ''; public $in_transaction = NULL; public 
$nested_transaction_counter = NULL; public $has_transaction_error = 
FALSE; public $offset = 0; public $limit = 0; public $phptype = 
'mysql'; public $dbsyntax = 'mysql'; public $last_query = 'SELECT 
DISTINCT s.* FROM ansel_shares s LEFT JOIN ansel_shares_users u ON 
u.share_id = s.share_id LEFT JOIN ansel_shares_groups g ON g.share_id 
= s.share_id WHERE (s.share_owner = \'jan\' OR (s.perm_creator & 2) OR 
(s.perm_default & 2) OR ( u.user_uid = \'jan\' AND (u.perm & 2)) OR 
(g.group_uid IN (\'8280\') AND (g.perm & 2))) AND (share_parents = 
\':4852\' OR share_parents LIKE \':4852:%\') ORDER BY s.share_id ASC'; 
public $fetchmode = 1; public $modules = array (...); public 
$destructor_registered = TRUE; public $_debug = FALSE; public 
$_default_error_mode = NULL; public $_default_error_options = NULL; 
public $_default_error_handler = ''; public $_error_class = 
'PEAR_Error'; public $_expected_errors = array (...); public $datatype 
= class MDB2_Driver_Datatype_mysql { ... }; public 
$loaded_version_modules = array (...) }; protected $_params = array 
('persistent' => FALSE, 'username' => 'horde', 'password' => 
'H20Kopf', 'socket' => '/var/lib/mysql/mysql.sock', 'protocol' => 
'unix', 'database' => 'horde', 'charset' => 'iso-8859-1', 'ssl' => 
FALSE, 'splitread' => FALSE, 'phptype' => 'mysql', 'hostspec' => ''); 
protected $_table = 'ansel_shares'; protected $_app = 'ansel'; 
protected $_root = NULL; protected $_cache = array (); protected 
$_shareMap = array (); protected $_listcache = array (); protected 
$_sortList = NULL; protected $_permsObject = class Horde_Perms_Sql { 
protected $_params = array (...); protected $_db = class 
Horde_Db_Adapter_Pdo_Mysql { ... }; private $_cacheVersion = 2; 
protected $_permsCache = array (...); protected $_cache = class 
Horde_Cache_File { ... }; protected $_logger = class 
Horde_Core_Log_Logger { ... }; protected $_appPerms = NULL } } }, 
array ('name' => 'ansel_polaroid', 'title' => 'Polaroid-Vorschau 
(Weißer Hintergrund)', 'thumbstyle' => 'PolaroidThumb', 'background' 
=> 'white', 'default_galleryimage_type' => 'PolaroidStack', 'widgets' 
=> array ('Actions' => array (), 'Tags' => array ('view' => 
'gallery'), 'OtherGalleries' => array (), 'Geotag' => array (), 
'Links' => array (), 'GalleryFaces' => array (), 'OwnerFaces' => array 
()), 'gallery_view' => 'Gallery', 'requires_png' => FALSE), FALSE, 
array ('page' => 0, 'sort' => NULL, 'sort_dir' => 0, 'year' => 0, 
'month' => 0, 'day' => 0, 'view' => 'List', 'gallery_view' => NULL, 
'gallery_id' => NULL, 'gallery_slug' => NULL, 'force_grouping' => 
NULL, 'image_id' => NULL, '_pagerurl' => class Horde_Url { public $url 
= '/headhorde/ansel/user/jan/'; public $raw = FALSE; public 
$parameters = array (); public $pathInfo = NULL; public $anchor = ''; 
public $toStringCallback = NULL }, '_pager' => class 
Horde_Core_Ui_Pager { protected $_preserve = array ('sort_dir' => 0, 
'sort' => 'name'); protected $_name = 'page'; protected $_vars = class 
Horde_Variables { protected $_vars = array (...); protected 
$_expectedVariables = array (...); protected $_sanitized = FALSE }; 
protected $_config = array ('page_limit' => 10, 'perpage' => '9', 
'num' => '2', 'url' => class Horde_Url { ... }); protected 
$_url_callback = array (0 => 'Horde', 1 => 'applicationUrl') }) 
)        ../Gallery.php:455
6        2,2274        28915364        Ansel_Gallery->getKeyImage( 'ansel_polaroid' 
)        ../Gallery.php:55
7        2,7109        29191904        Ansel_ImageGenerator->create( )        ../Gallery.php:606
8        2,7109        29191904        Ansel_ImageGenerator_PolaroidStack->_create( 
)        ../ImageGenerator.php:84
9        2,7109        29191904        Ansel_ImageGenerator->_getStackImages( 
)        ../PolaroidStack.php:18