trunk: XML Editor restored on launch allows to add/set attribute without selection and crashes (rev >= 12682)

[su_v]

If inkscape opens the XML Editor on launch (restored from last session), the dialog shows an empty attribute list and the name/value entries below (those are normally hidden and only shown when there is a selection if the dialog is opened later in the session instead). Using the name/value entries in such a state triggers a crash on 'Set' (or 'Ctrl+Enter').

Steps to reproduce:
1) launch trunk with default (new) prefs, default doc (locale: en_US)
2) open the XML Editor
3) quit
4) relaunch
5) in the XML Editor, ignore that no object is selected and just add a new attribute:
6) type a string into the empty 'Attribute Name' entry (e.g. "foo" without the quotes)
7) press 'Set' (or use the keyboard shortcut 'Ctrl+Enter')

--> crash:
**
ERROR:../../src/ui/dialog/xml-tree.cpp:1020:void Inkscape::UI::Dialog::XmlTree::cmd_set_attr(): assertion failed: (selected_repr != NULL)

Based on tests with archived builds on OS X 10.7.5:
- not reproduced with stable 0.48.4, 0.48.5 (XML Editor is never in such a state)
- not reproduced with 0.48+devel rev <= r12679
- reproduced with 0.48+devel rev >= 12682
this regression appears to be related to the changes in revision 12682: “we don't have nondocked dialogs, so rewrite restoring dialogs on startup via DialogManager; do not grab focus when restoring”
<http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/12682>

Originally reported by agaida on #inkscape.de for trunk build .91pre revision bzr13469 on siduction;
reproduced with Inkscape 0.48+devel r13469 and r13470 on OS X 10.7.5

[su_v (suv-lp)]

After typing into the 'Attribute Name' field, the 'Set' button turns active, even though there is no object selected to which this attribute would be added.

[Liam P. White (liampwhite)]

Fixed in lp:inkscape, revision 13471.