This patch closes a memory leak that passes through desktop-style.cpp. It showed up in valgrind. A very little fish from a long day of fishing!
I was looking for leaks I might have introduced with the changes I have been working on. Found a couple of minor ones in my code and fixed those (it isn't in trunk yet, so no point posting them here), but it was extremely difficult since opening the program, doing not much of anything, and closing it, results in a 0.5M line valgrind log, with 49511 loss records.
There is a really nasty set of leaks associated with nr-style.cpp/h that I could not successfully repair. Apparently there are lines of execution which pass through drawing-text.cpp/drawing-shape.cpp and store things in one or more of the 5 pointer fields of an NRStyle object. In theory when the DrawingText or DrawingShape object goes away its destructor should clean these out. In practice many of them persist all the way until Inkscape exits. I tried adding an _nrstyle.clean() method, basically just what is already in the destructor, plus code to set the pointers to NULL after emptying their contents, and placed it at the end of the methods that call appply/prepareFill()/Stroke(), ie, the ones that actually draw things. That "fixed" the memory leak, but it made the drawing surface unstable. For instance, zooming in or out made things disappear. So that approach isn't going to fly. It wasn't a comprehensive fix in any case, since the objects that included the problem NRStyle objects were not removed. (This broken fix is not part of the current patch.)
Thanks for sharing this fix.
Committed in trunk revision 13013.