Fatal error:__clone method called on non-object

My guess now is that my problem is being caused by a task handler that I added to the page that I don't seem to have finished. The task handler has no display value in its $conf settings, which ultimately ends up in drupal_clone() trying to clone a NULL value.

It's hard to say if that happened because I just started configuring a task handler and never finished configuring it all the wayl, or if it's the result of a small utility module that I had added to my project that is defining an additional selection criteria that I needed for my specific project. Either way, I'd certainly ideally prefer the system catch things like that -- even if it's Panels saying, "hey, I don't know how but this task handler is busted, so go figure out what's wrong or delete it."

Anyway, the fix for me was a simple:

... added toward the top of panels_panel_context_admin_summary().

Once that check is in, the defective handler (which somehow has no conf->display set) can be deleted, and everything is good to go.

(As a side note: since drupal_clone() curiously does not validate its parameters and assumes everything is alright, I'd think it to be a good idea to do that basic validation to avoid meaningless error messages like "clone method called on non-object" (and replace that error message with a "invalid task handler"-type message that Panels could show.)

Sorry, you probably didn't find the string because it's not literally panels_panel_context_admin_summary(), but the full function panels_panel_context_admin_summary($handler, $task, $subtask_id). The function should be in sites/all/modules/panels/plugins/task_handlers/panel_context.inc around line 220.

So I'm glad there's a temporary fix here, but I can't recommend PeteS's solution for any sort of long term. The validation that prevents this needs to happen earlier in the stack, putting it directly into the task handler plugin as a workaround for some not-so-hot logic in the core is unsustainable.

Re: drupal_clone(), it's doubtful such a change would ever go in, and imo shouldn't. Two basic reasons: drupal's general "don't babysit broken code" rule, and also because drupal_clone() works quite well right now as just a shorthand function for people who don't want to do the somewhat awkward version comparison in their own code.

On the same side as PeteS, some of us are on deadlines to complete projects, therefore, we can't just sit on our ass waiting for some update (and not knowing when one may come- I've heard April).

So to me, this is completely acceptable short term, to get things done. We can worry about updating it later, as we are competent enough to maintain codebases.

However, he is correct that this simple and obvious bug shouldn't exist in the first place.

Merlin, I don't think you need take offence -- as I read it the other guys were aware it's alpha code, happy to go with short term workarounds and were digressing into discussion of longer term software engineering principles (i.e. whether "no babysitting" is a viable usability/performance trade-off). The ref to "simple and obvious bug" isn't critical of the presence of oversights, but is just mentioning that firewalls elsewhere could reduce their impact.

Funny thing -- when people start getting passionate discussing a piece of software and forget courtesies, it's often because they like the software a lot and want to see it even better!

Automatically closed -- issue fixed for 2 weeks with no activity.

Does anyone have a thought on where this same temp fix would need to be applied to 5.x? I'm getting this error ...

... but there is no panel_context.inc or panels_panel_context_admin_summary() function. There are 20 panels files in 5.x which reference drupal_clone(). I narrowed down to panels_mini.module, panels_page.module, panels.module, and display_edit.inc as files which use the drupal_clone() function, but didn't have any handling in front of them in the case where a value might be empty.

In front of the four situations where drupal_clone is called, I added a line similar to this (obviously variable/array is changed in each unique situation):

It didn't seem to work. This is a situation where I am creating a view to be added as a separate group page under another tab. I was able to add a first page summarizing group posts, but the second page used to present a group event calendar causes the problem.

I'm getting this with Panels 3.2:
( ! ) Fatal error: __clone method called on non-object in [path]/includes/common.inc on line 1956

To see this happening, have the taxonomy/term handler enabled and try to load a taxonomy/term page that doesn't exist, e.g.:
http://example.com/taxonomy/term/9999999

For me this results in the following:

• Time - Memory - Function
• 0.0006 - 64944 - {main}( ) - ../index.php:0
• 0.7810 - 40122164 - menu_execute_active_handler( $path = ??? ) - ../index.php:18
• 0.7848 - 40187580 - call_user_func_array ( 'page_manager_term_view', array (0 => '9999999') ) - ../menu.inc:348
• 0.7848 - 40187684 - page_manager_term_view( $terms = '9999999', $depth = ???, $op = ??? ) - ../menu.inc:0
• 0.8297 - 40857064 - ctools_context_handler_render( $task = array ('task type' => 'page', 'title' => 'Taxonomy term template', 'admin title' => 'Taxonomy term template', 'admin description' => 'When enabled, this overrides the default Drupal behavior for displaying taxonomy terms at taxonomy/term/%term. If you add variants, you may use selection criteria such as vocabulary or user access to provide different displays of the taxonomy term and associated nodes. If no variant is selected, the default Drupal taxonomy term display will be used. This page only affects items actually displayed ad taxonomy/term/%term. Some taxonomy terms, such as forums, have their displays moved elsewhere. Also ...', 'admin path' => 'taxonomy/term/%term', 'admin summary' => 'page_manager_term_view_admin_summary', 'hook menu' => 'page_manager_term_view_menu', 'hook menu alter' => 'page_manager_term_view_menu_alter', 'admin settings' => 'page_manager_term_view_admin_settings', 'save subtask callback' => 'page_manager_term_view_save', 'task admin' => 'page_manager_term_view_task_admin', 'handler type' => 'context', 'get arguments' => 'page_manager_term_view_get_arguments', 'get context placeholders' => 'page_manager_term_view_get_contexts', 'operations' => array ('settings' => array (...)), 'disabled' => FALSE, 'enable callback' => 'page_manager_term_view_enable', 'module' => 'page_manager', 'name' => 'term_view', 'path' => 'sites/all/modules/platform/ctools/page_manager/plugins/tasks', 'file' => 'term_view.inc', 'plugin module' => 'page_manager', 'plugin type' => 'tasks'), $subtask = '', $contexts = array ('argument_terms_1' => class ctools_context { public $type = array (...); public $data = FALSE; public $title = NULL; public $page_title = ''; public $identifier = 'Term(s) being viewed'; public $argument = '9999999'; public $keyword = 'term'; public $original_argument = '9999999'; public $restrictions = array (...); public $empty = FALSE; public $plugin = 'terms'; public $operator = 'and'; public $tids = array (...); public $id = 'argument_terms_1' }), $args = array (0 => '9999999', 1 => 0, 2 => 'page'), $page = ??? ) - ../term_view.inc:140
• 0.9182 - 42958104 - panels_panel_context_render( $handler = class stdClass { public $did = '12'; public $name = 'term_view_panel_context_2'; public $task = 'term_view'; public $subtask = ''; public $handler = 'panel_context'; public $weight = '-3'; public $conf = array ('autogenerate_title' => TRUE, 'title' => 'Panel', 'no_blocks' => 0, 'css_id' => 'term-page', 'css' => '', 'contexts' => array (...), 'relationships' => array (...), 'access' => array (...), 'did' => '27', 'display' => class panels_display { ... }); public $table = 'page_manager_handlers'; public $type = 'Normal'; public $export_type = 1 }, $base_contexts = array ('argument_terms_1' => class ctools_context { public $type = array (...); public $data = FALSE; public $title = NULL; public $page_title = ''; public $identifier = 'Term(s) being viewed'; public $argument = '9999999'; public $keyword = 'term'; public $original_argument = '9999999'; public $restrictions = array (...); public $empty = FALSE; public $plugin = 'terms'; public $operator = 'and'; public $tids = array (...); public $id = 'argument_terms_1' }), $args = array (0 => '9999999', 1 => 0, 2 => 'page'), $test = ??? ) - ../context-task-handler.inc:46
• 0.9220 - 42965556 - panels_render_display( $display = class panels_display { public $args = array (0 => '9999999', 1 => 0, 2 => 'page'); public $content = array (291 => class stdClass { ... }, 315 => class stdClass { ... }, 312 => class stdClass { ... }, 103 => class stdClass { ... }, 104 => class stdClass { ... }); public $panels = array ('left' => array (...), 'right' => array (...)); public $incoming_content = NULL; public $css_id = 'term-page'; public $context = array ('argument_terms_1' => class ctools_context { ... }); public $did = '27'; public $layout = 'twocol'; public $layout_settings = array (); public $panel_settings = array (); public $cache = array (); public $title = ''; public $hide_title = '1'; public $title_pane = '0' } ) - ../panel_context.inc:276
• 0.9249 - 43128520 - _panels_render_display( $display = class panels_display { public $args = array (0 => '9999999', 1 => 0, 2 => 'page'); public $content = array (291 => class stdClass { ... }, 315 => class stdClass { ... }, 312 => class stdClass { ... }, 103 => class stdClass { ... }, 104 => class stdClass { ... }); public $panels = array ('left' => array (...), 'right' => array (...)); public $incoming_content = NULL; public $css_id = 'term-page'; public $context = array ('argument_terms_1' => class ctools_context { ... }); public $did = '27'; public $layout = 'twocol'; public $layout_settings = array (); public $panel_settings = array (); public $cache = array (); public $title = ''; public $hide_title = '1'; public $title_pane = '0' } ) - ../panels.module:821
• 1.0426 - 43370896 - panels_render_layout( $layout = array ('title' => 'Two column', 'icon' => 'twocol.png', 'theme' => 'panels_twocol', 'css' => 'twocol.css', 'panels' => array ('left' => 'Left side', 'right' => 'Right side'), 'module' => 'panels', 'name' => 'twocol', 'path' => 'sites/all/modules/platform/panels3/plugins/layouts/twocol', 'file' => 'twocol.inc', 'plugin module' => 'panels', 'plugin type' => 'layouts'), $content = class panels_display { public $args = array (0 => '9999999', 1 => 0, 2 => 'page'); public $content = array (291 => class stdClass { ... }, 315 => class stdClass { ... }, 312 => class stdClass { ... }, 103 => class stdClass { ... }, 104 => class stdClass { ... }); public $panels = array ('left' => array (...), 'right' => array (...)); public $incoming_content = NULL; public $css_id = 'term-page'; public $context = array ('argument_terms_1' => class ctools_context { ... }); public $did = '27'; public $layout = 'twocol'; public $layout_settings = array (); public $panel_settings = array (); public $cache = array (); public $title = ''; public $hide_title = '1'; public $title_pane = '0' }, $css_id = 'term-page', $settings = array (), $display = ??? ) - ../display-render.inc:36
• 1.0427 - 43371784 - panels_render_panes( $display = class panels_display { public $args = array (0 => '9999999', 1 => 0, 2 => 'page'); public $content = array (291 => class stdClass { ... }, 315 => class stdClass { ... }, 312 => class stdClass { ... }, 103 => class stdClass { ... }, 104 => class stdClass { ... }); public $panels = array ('left' => array (...), 'right' => array (...)); public $incoming_content = NULL; public $css_id = 'term-page'; public $context = array ('argument_terms_1' => class ctools_context { ... }); public $did = '27'; public $layout = 'twocol'; public $layout_settings = array (); public $panel_settings = array (); public $cache = array (); public $title = ''; public $hide_title = '1'; public $title_pane = '0' } ) - ../display-render.inc:84
• 1.0940 - 43645732 - panels_render_pane_content( $display = class panels_display { public $args = array (0 => '9999999', 1 => 0, 2 => 'page'); public $content = array (291 => class stdClass { ... }, 315 => class stdClass { ... }, 312 => class stdClass { ... }, 103 => class stdClass { ... }, 104 => class stdClass { ... }); public $panels = array ('left' => array (...), 'right' => array (...)); public $incoming_content = NULL; public $css_id = 'term-page'; public $context = array ('argument_terms_1' => class ctools_context { ... }); public $did = '27'; public $layout = 'twocol'; public $layout_settings = array (); public $panel_settings = array (); public $cache = array (); public $title = ''; public $hide_title = '1'; public $title_pane = '0' }, $pane = class stdClass { public $pid = '315'; public $did = '27'; public $panel = 'left'; public $type = 'term_list'; public $subtype = 'term_list'; public $shown = TRUE; public $access = array (); public $configuration = array ('title' => NULL, 'type' => 'child', 'list_type' => 'ul', 'context' => 'argument_terms_1', 'override_title' => 0, 'override_title_text' => ''); public $cache = array ('method' => 'signal_cache_panel', 'settings' => array (...)); public $style = array (); public $css = array (); public $extras = array (); public $position = '1' }, $keywords = array () ) - ../display-render.inc:157
• 1.0940 - 43646080 - panels_get_pane_content( $display = class panels_display { public $args = array (0 => '9999999', 1 => 0, 2 => 'page'); public $content = array (291 => class stdClass { ... }, 315 => class stdClass { ... }, 312 => class stdClass { ... }, 103 => class stdClass { ... }, 104 => class stdClass { ... }); public $panels = array ('left' => array (...), 'right' => array (...)); public $incoming_content = NULL; public $css_id = 'term-page'; public $context = array ('argument_terms_1' => class ctools_context { ... }); public $did = '27'; public $layout = 'twocol'; public $layout_settings = array (); public $panel_settings = array (); public $cache = array (); public $title = ''; public $hide_title = '1'; public $title_pane = '0' }, $pane = class stdClass { public $pid = '315'; public $did = '27'; public $panel = 'left'; public $type = 'term_list'; public $subtype = 'term_list'; public $shown = TRUE; public $access = array (); public $configuration = array ('title' => NULL, 'type' => 'child', 'list_type' => 'ul', 'context' => 'argument_terms_1', 'override_title' => 0, 'override_title_text' => ''); public $cache = array ('method' => 'signal_cache_panel', 'settings' => array (...)); public $style = array (); public $css = array (); public $extras = array (); public $position = '1' }, $keywords = array (), $args = array (0 => '9999999', 1 => 0, 2 => 'page'), $context = array ('argument_terms_1' => class ctools_context { public $type = array (...); public $data = FALSE; public $title = NULL; public $page_title = ''; public $identifier = 'Term(s) being viewed'; public $argument = '9999999'; public $keyword = 'term'; public $original_argument = '9999999'; public $restrictions = array (...); public $empty = FALSE; public $plugin = 'terms'; public $operator = 'and'; public $tids = array (...); public $id = 'argument_terms_1' }), $incoming_content = NULL ) - ../display-render.inc:211
• 1.0962 - 43655312 - ctools_content_render( $type = 'term_list', $subtype = 'term_list', $conf = array ('title' => NULL, 'type' => 'child', 'list_type' => 'ul', 'context' => 'argument_terms_1', 'override_title' => 0, 'override_title_text' => ''), $keywords = array (), $args = array (0 => '9999999', 1 => 0, 2 => 'page'), $context = array ('argument_terms_1' => class ctools_context { public $type = array (...); public $data = FALSE; public $title = NULL; public $page_title = ''; public $identifier = 'Term(s) being viewed'; public $argument = '9999999'; public $keyword = 'term'; public $original_argument = '9999999'; public $restrictions = array (...); public $empty = FALSE; public $plugin = 'terms'; public $operator = 'and'; public $tids = array (...); public $id = 'argument_terms_1' }), $incoming_content = NULL ) - ../plugins.inc:64
• 1.0969 - 43656460 - ctools_term_list_content_type_render( $subtype = 'term_list', $conf = array ('title' => NULL, 'type' => 'child', 'list_type' => 'ul', 'context' => 'argument_terms_1', 'override_title' => 0, 'override_title_text' => ''), $panel_args = array (0 => '9999999', 1 => 0, 2 => 'page'), $context = class ctools_context { public $type = array (0 => 'terms', 1 => 'term'); public $data = FALSE; public $title = NULL; public $page_title = ''; public $identifier = 'Term(s) being viewed'; public $argument = '9999999'; public $keyword = 'term'; public $original_argument = '9999999'; public $restrictions = array (); public $empty = FALSE; public $plugin = 'terms'; public $operator = 'and'; public $tids = array (0 => 9999999); public $id = 'argument_terms_1' }, NULL ) - ../content.inc:264
• 1.0969 - 43657628 - drupal_clone( $object = FALSE )

just wanted to tag this comment to bring attention to the comment above it I forgot to tag.

Shoudl've marked this when I said I could not reproduce it.

I did some further testing.

It also happens with user required context.

It does not happen with context that is not required.

I was checking, whether the context in the mother panel is actually there, and yes / as it is a node view, the Node being viewed is there.....

regards
Christian

I am putting it back to closed, cannot reproduce.

Works now as it should.