Comment 1 for bug 1492615

Reproduced (crash including lack of emergency save) with Inkscape 0.91 r13725 and 0.91+devel r14341 on OS X 10.7.5:

(inkscape:56570): glibmm-ERROR **:
unhandled exception (type std::exception) in signal handler:
what: basic_string::_S_construct NULL not valid

Based on tests with archived builds:
- not reproduced with rev <= 13056,
- reproduced with rev >= 13058;
the crash was possibly exposed as side-effect of the changes in rev 13057:
Revision 13057: Rewrite of symbol creation code. Partial fix for 1201325.
https://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/13057