Crash when combining a preset filter and an empty user defined one

[jazzynico]

Reproduced on Windows XP and Ubuntu 9.04, rev. 22241.
Steps:
1. Draw an object and select it.
2. Open the filters editor.
3. Add a new blank filter (with no effect) and select it.
4. Add a preset filter in the Filters menu to the blank filter. Crash!

Everything is ok if the new filter has an effect.

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0xb5e8f770 (LWP 26993)]
0x0823cbc1 in Inkscape::Extension::Internal::Filter::Filter::effect (this=0x9f896c0, module=0x9f8b970, document=0xa2d9db0,
    docCache=0x0) at extension/internal/filter/filter.cpp:177
177 filternode->lastChild()->setAttribute("result", FILTER_SRC_GRAPHIC);

Backtrace attached.

[su_v (suv-lp)]

Confirmed with Inkscape 0.46+devel 22240 on OS X 10.5.8

[theAdib (theadib)]

attached patch solves the crash situation originated from nr-filter.cpp and should merge a choosen filter into the selected one.
pls test. Adib.

[jazzynico (jazzynico)]

Patch tested. Inkscape no longer crashes.
Thanks!

[su_v (suv-lp)]

Patch tested on OS X as well: Inkscape no longer crashes but applies the predefined filter instead of (or merged with?) the empty new one. Thanks.

[jazzynico (jazzynico)]

Tested successfully on Windows XP.

@~suv. The predefined filter and the blank one are merged, and the resulting filter get the last added filter's name (although the label is not updated in the editor...). That's also what happens when you apply two (or more) predefined filters.

[ScislaC (scislac)]

Applied in r22271. Thanks Adib!