Dropping time signature from master palette onto measure will crash

I was doing some more testing while fixing my other problem, and I managed to crash by dropping 4/4 from workspace palette onto first meas of score which already had a custom 3/8 timesig...I don't think my earlier PRs could be at fault...I would have to test an earlier windows 3.0 build.

1 QListData::size qlist.h 107 0xde9878
2 QList::operator[] qlist.h 535 0xdd9d25
3 Ms::System::staff system.h 114 0xdbfbaf
4 Ms::StaffLines::pagePos stafflines.cpp 53 0x8f5b68
5 Ms::StaffLines::canvasPos stafflines.cpp 62 0x8f5bf5
6 Ms::Element::canvasPos element.cpp 456 0x7ebddc
7 Ms::Element::canvasBoundingRect element.h 273 0xdc0859
8 Ms::ScoreView::dropEvent dragdrop.cpp 588 0x5bce33
9 ZN7QWidget5eventEP6QEvent 0x61e0dad1
10 ?? 0x1ebcbd8c
11 ?? 0x8ec8300

well that's funny...I downloaded windows 3.0 build fcc5123 and found that I'm not able to drag time signatures from palettes, while somehow my self compile is able to drag time signatures from palette.

very strange I'm also able to drag & drop time sigs in the 3.0 build 89bd22c which does contain my latest PRs. The crash doesn't happen every time that drop a time signature. Note can be from workspace palette or form master palette. Seem to happen more when dropping on first measure.

I can't reproduce on 2.1 286a444 try as I might. I am able able to drag and drop the time sigs from both the master palette and workspace. So I don't know quite why I'm all of the sudden am able to drag and drop time signatures from pallete but wasn't before. But It seems this crash only occurs on 3.0 at least, fortunately.

Just making a note that is still present in 1725d1f84 (I was checking because I was curious if https://github.com/musescore/MuseScore/commit/1725d1f845eb76339aa3d2e10… had somehow fixed it)

1 QListData::size qlist.h 107 0xde9878
2 QList::operator[] qlist.h 535 0xdd9d25
3 Ms::System::staff system.h 114 0xdbfbaf
4 Ms::StaffLines::pagePos stafflines.cpp 53 0x8f5b68
5 Ms::StaffLines::canvasPos stafflines.cpp 62 0x8f5bf5
6 Ms::Element::canvasPos element.cpp 456 0x7ebddc
7 Ms::Element::canvasBoundingRect element.h 273 0xdc0859
8 Ms::ScoreView::dropEvent dragdrop.cpp 588 0x5bce33
9 ZN7QWidget5eventEP6QEvent 0x61e0dad1
10 ?? 0x1ebcbd8c
11 ?? 0x8ec8300

thanks cadiz for the update. I'm looking at commit history, and this commit by werner titled "misc. fixes for time signatures" sounds like the most likely one that fixed it:

https://github.com/musescore/MuseScore/commit/2a5152a6a5708303a51936aee…

probably around here was the fix: https://github.com/musescore/MuseScore/commit/2a5152a6a5708303a51936aee…