Item10356: Foswiki server error when using WorkflowPlugin with a state transition form

• Foswiki 1.0.10
• WorkflowPlugin 25 Aug 2010 (8761)

Foswiki aborts with a server error when attempting to transition the workflow example Sandbox.ControlledDocument from UNDERREVISION to WAITNGFORQM using the "ready for approval" button and the Sandbox.InProcessForm

| 2011-02-15T05:50:02Z warning | Can't call method "getFieldValuesFromQuery" on an undefined value at /var/www/wiki.mot-mobility.com/lib/Foswiki/UI/Edit.pm line 376.
 at /var/www/wiki.mot-mobility.com/lib/Foswiki/UI/Edit.pm line 376
	Foswiki::UI::Edit::init_edit('Foswiki=HASH(0xba676ac)', 'edit') called at /var/www/wiki.mot-mobility.com/lib/Foswiki/UI/Edit.pm line 44
	Foswiki::UI::Edit::edit('Foswiki=HASH(0xba676ac)') called at /var/www/wiki.mot-mobility.com/lib/Foswiki/UI.pm line 304
	Foswiki::UI::__ANON__() called at /var/www/wiki.mot-mobility.com/lib/CPAN/lib/Error.pm line 379
	eval {...} called at /var/www/wiki.mot-mobility.com/lib/CPAN/lib/Error.pm line 371
	Error::subs::try('CODE(0xf0a16a8)', 'HASH(0xe123370)') called at /var/www/wiki.mot-mobility.com/lib/Foswiki/UI.pm line 391
	Foswiki::UI::_execute('Foswiki::Request=HASH(0xe108e48)', 'CODE(0xde0160c)', 'edit', 1) called at /var/www/wiki.mot-mobility.com/lib/Foswiki/UI.pm line 275
	Foswiki::UI::handleRequest('Foswiki::Request=HASH(0xe108e48)') called at /var/www/wiki.mot-mobility.com/lib/Foswiki/Engine/Apache.pm line 87
	Foswiki::Engine::Apache::run('Apache2::RequestRec=SCALAR(0xbe9f7f0)') called at /var/www/wiki.mot-mobility.com/lib/Foswiki/Form.pm line 0
	eval {...} called
 |

The problem is a META:FORM{name="InProcessForm "} setting, generated during processing of the changeState REST request, that contains a form name with a trailing space in it. That is an invalid topic name, of course, so the Foswiki::Form constructor fails leaving $formDef undefined at Foswiki::UI::Edit.pm line 376.

367	        require Foswiki::Form;
368	        my $formDef = new Foswiki::Form( $session, $templateWeb, $form );
369	        if ( !$formDef ) {
370	
371	            # Reverse-engineer a form definition from the meta-data.
372	            $formDef = new Foswiki::Form( $session, $templateWeb, $form, $meta );
373	        }
374	
375	        # Update with field values from the query
376	        $formDef->getFieldValuesFromQuery( $session->{request}, $meta );

The ultimate culprit turned out to be the regexes at Foswiki::Plugins::WorkflowPlugin::Workflow.pm line 89 and line 93.

89	        elsif ( defined($inTable) && $line =~ s/^\s*\|\s*(.*)\s*\|$/$1/ ) {
90	
91	            my %data;
92	            my $i = 0;
93	            foreach my $col (split(/\s*\|\s*/, $line)) {
94	                $data{$fields[$i++]} = $col;
95	            }
96	
97	            if ($inTable eq 'TRANSITION') {
98	                push( @{ $this->{transitions} }, \%data );
99	            } elsif ($inTable eq 'STATE') {
100	                # read row in STATE table
101	                $this->{defaultState} ||= $data{state};
102	                $this->{states}->{ $data{state} } = \%data;
103	            }
104	        }

Since the capture of the $1 term is greedy, any trailing spaces in the last cell of the table will be captured right along with the rest of the cell contents. In addition, since it is the final cell, the split regex at line 93 won't be applied to it and won't consume those trailing spaces. The fix is to make the $1 term minimal or non-greedy.

89	        elsif ( defined($inTable) && $line =~ s/^\s*\|\s*(.*?)\s*\|$/$1/ ) {

While that solves the immediate issue, it does illustrate that the Foswiki::Form constructor can fail and that situation should be caught and dealt with somehow at Foswiki::UI::Edit.pm line 376 without killing Foswiki.

-- BryanThale - 15 Feb 2011

Fixed in WorkflowPlugin:3db8c4677cca. WorkflowPlugin:ee59fe0c9f0e rolls back my no-longer-necessary fix in ControlledTopic.pm.

-- AaronFuleki - 23 Feb 2011

Released in WorkflowPlugin 1.12.1 (01 Mar 2011)

-- BryanThale - 01 Mar 2011

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