Staff/Part properties >> Advanced Style Properties >> Stemless crashes MuseScore

Crashes are critical.
Regression vs what?

I can't reproduce. You say you created a new score, but how exactly? Does fail with other scores too? Can you attach a specific score where it fails for you?

Indeed. I can reproduce with the last nightly: OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit): 3.5.0.10755, revision: 1163513

This issue occurs on last February 10 or February 11.
- This nightly works: 32812a2
- This one crashes: 8079351
There is eight commits between them. Must be check where it's happening.

Stack trace:
1 Ms::Stem::lineWidthMag stem.h 66 0xf97a34
2 Ms::Beam::layout2 beam.cpp 1789 0x877ced
3 Ms::Beam::layout beam.cpp 542 0x86d910
4 Ms::Score::layoutSystemElements layout.cpp 3633 0x940386
5 Ms::LayoutContext::layoutLinear layoutlinear.cpp 206 0xb1f1f1
6 Ms::Score::layoutLinear layoutlinear.cpp 195 0xb1f184
7 Ms::Score::doLayoutRange layout.cpp 4436 0x945e9a
8 Ms::Score::doLayout layout.cpp 4347 0x945739
9 Ms::EditStaffType::updatePreview editstafftype.cpp 549 0x7d1ce4
10 Ms::EditStaffType::qt_static_metacall moc_editstafftype.cpp 114 0x62598b
11 QMetaObject::activate(QObject *, int, int, void * *) 0x68a947c8
12 QAbstractButton::toggled(bool) 0x2a16e4cb
13 QAbstractButton::setChecked(bool) 0x2a16f9d1
14 QCheckBox::nextCheckState() 0x2a17d0b8
15 QAbstractButton::setIconSize(QSize const&) 0x2a16f53d
16 QAbstractButton::mouseReleaseEvent(QMouseEvent *) 0x2a16f775
17 QWidget::event(QEvent *) 0x2a0d5f18
18 QApplicationPrivate::notify_helper(QObject *, QEvent *) 0x2a097bdc
19 QApplication::notify(QObject *, QEvent *) 0x2a09fc1a
20 QCoreApplication::sendSpontaneousEvent(QObject *, QEvent *) 0x68a694a8
...

Possible fix:

diff --git a/libmscore/beam.cpp b/libmscore/beam.cpp
index d1e6144ef..244d42711 100644
--- a/libmscore/beam.cpp
+++ b/libmscore/beam.cpp
@@ -1786,7 +1786,7 @@ void Beam::layout2(std::vector<ChordRest*>crl, SpannerSegmentType, int frag)
                               crBase[i1] = bl;
                         }
 
-                  qreal stemWidth  = cr1->isChord() ? toChord(cr1)->stem()->lineWidthMag() : 0.0;
+                  qreal stemWidth  = cr1->isChord() && toChord(cr1)->stem() ? toChord(cr1)->stem()->lineWidthMag() : 0.0;
                   qreal x2         = cr1->stemPosX() + cr1->pageX() - _pagePos.x();
                   qreal x3;
 
@@ -1803,7 +1803,7 @@ void Beam::layout2(std::vector<ChordRest*>crl, SpannerSegmentType, int frag)
                               if (cr1->up())
                                     x2 -= stemWidth;
                               if (!chordRest2->up())
-                                    x3 += chordRest2->isChord() ? toChord(chordRest2)->stem()->lineWidthMag() : 0.0;
+                                    x3 += chordRest2->isChord() && toChord(chordRest2)->stem() ? toChord(chordRest2)->stem()->lineWidthMag() : 0.0;
                               }
                         }
                   else {

See https://github.com/musescore/MuseScore/pull/5893

Culprit as per git blame seems 314f8ac62, although I don't understand why, the wrong access to the withd of a non-existing stem should have happend before too

Hmm, no, seems 57d8a1841 introduced this (as per git log the previous change to that file and those lines)
So the fix for #291699: Stems and beams for small chords don't align correctly, PR https://github.com/musescore/MuseScore/pull/5669.

I'm not mentioning this here for finger-pointing of a blame game, but to make sure I caught the right spots to fix this issue

I build just before and after the merge of PR5669 and this indeed causes this issue. Also applied PR5863 straight on PR5669 and this indeed solves the issue.

Thanks for verifying

Thanks for solving!

Fixed in branch master, commit 263d5d91d7

_fix #303189: Staff/Part properties > Advanced Style Properties > Stemless crashes MuseScore

The problem is that a stem's lineWidthMag() was asked for even if
there is no stem (anymore).

Apparently caused by the changes in #5669 / 57d8a1841 for fixing
#291699_

Fixed in branch master, commit 409aa87dad

_Merge pull request #5893 from Jojo-Schmitz/stemles-crash

fix #303189: Staff/Part properties > Advanced Style Properties > Stemless crashes MuseScore_

Automatically closed -- issue fixed for 2 weeks with no activity.