Crash on Undo of Break apart with Fill+Stroke Dialog open (rev >= 11614)

Duplicate of (or at least related to) Bug #1417173 “Crash when undoing change to duplicated gradient”?
https://bugs.launchpad.net/inkscape/+bug/1417173

Reproduced with Inkscape 0.91+devel r14063 on OS X 10.7.5

Nevermind the reference to bug ##1417173 - the crash reported here can be reproduced with r12050 too.

Based on tests with archived builds on OS X 10.7.5:
- crash not reproduced with rev <= 11613,
- crash reproduced with rev >= 11614;
the regression seems to be a side-effect of
Revision 11614: Fix for bug #165865 : markers must take object's stroke color
http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/11614

Crash is not related to gradient (can be reproduced with attached file which uses flat fill color instead of gradient).

Triggers appear to be these properties in the path's style attribute:
       "marker-start:none;marker-mid:none;marker-end:none"

(no crash if removed, see attached version of the file)

The style properties which seem to trigger the crash also play a role e.g. in bug #1372151 (where they may break 'redo' if fill&stroke is open).

Other reports related to markers and undo: bug #1198530, bug #1357805.

Thank you very much, ~suv, for investigating the issue!

Same workaround also effective to avoid crash reported in
* Bug #1424717 “Error when undoing a “cut path” operation”
  https://bugs.launchpad.net/inkscape/+bug/1424717

I can confirm this happens on Windows 7, 64-bit, sp1 and in Inkscape 0.91, 32-bit (exe installer) and 64-bit (7z version).

I can provide a test file if needed. Just let me know :-)

Thanks,
brynn

the following patch works:

=== modified file 'src/widgets/stroke-style.cpp'
--- src/widgets/stroke-style.cpp 2016-03-08 01:23:26 +0000
+++ src/widgets/stroke-style.cpp 2016-06-16 12:54:36 +0000
@@ -1303,10 +1303,6 @@

             if (update) {
                 setMarkerColor(marker, combo->get_loc(), SP_ITEM(object));
-
- SPDocument *document = desktop->getDocument();
- DocumentUndo::done(document, SP_VERB_DIALOG_FILL_STROKE,
- _("Set marker color"));
             }

         } else {

any idea why these lines are there ? (iiuc, they sort of mean that the automatic setting of marker colors is individually undoable (?) (correct me if i'm wrong), even if it's in the middle of a larger operation).
Could people please test this patch, (this code was introduced in r11614 to fix https://bugs.launchpad.net/inkscape/+bug/165865 , so regressions would likely be related to marker colors [and/or Undo] )
If someone knows more than I do about the DocumentUndo::maybeDone stuff, maybe take a look there ?

Regarding comment #12:
The patch removes the action in the Undo history dialog, but it's still possible to undo the markers color change with Ctrl+Z. Inkscape then adds an empty line in the Undo history, and shows the following messages:
----
** (inkscape.exe:3464): WARNING **: Incomplete undo transaction:
** (inkscape.exe:3464): WARNING **: Event: Set attribute style to "fill-rule:evenodd;stroke-width:0.625;stroke-linejoin:round;stroke:#000000;stroke-opacity:1;fill:#ff0000;fill-opacity:1" on #<Element:0x09568af0>
----

Replicated in Inkscape 0.92.4, not replicated in 1.1-dev (c990a67, 2020-04-09), Windows 10. There have been a lot of changes to the code in question, see https://gitlab.com/inkscape/inkscape/-/blame/master/src/widgets/stroke-style.cpp#L1317, so I'll assume it's fixed. There is also no message indicating an incomplete undo transaction. Please reopen on http://inkscape.org/report if the problem occurs again.

Closed by: https://gitlab.com/jhofinger