Duplicate / corrupt lines on save/reload in file imported from MusicXML
Ubuntu 14.04, GIT commit: 79a8fc8
1) load the attached MusicXML file, which contains a few simple text "direction" elements, including a "text line" at the start of measure 2. I created this MusicXML in MuseScore but manually moved the direction element in measure 1 from the beginning to the end of the measure, which seems to be a necessary condition for the bug to appear.
2) save (as MSCZ)
3) load the MSCZ
4) drag the textline in any direction
Result: you will see a duplicate textline (of zero length) has been created. Save and load again, and you get two more duplicates - it doubles each time. See #67001: Crash on opening file with apparently invalid note anchored textline - in this case, there were ~4096 duplicates of the line.
This issue is seen in both 2.0.1 and in current builds, so it apparently affects both the DOM and pull parsers.
I believe the MSCZ saved at step 2 is corrupt - it contains two textline starts with the same id. Somehow, this error keeps compounding itself.
I don't totally understand the cause of the problem, but I think it has to do with the direction element at the end of meausre 1 - I can't reproduce see the problem without it. But I also don't see the problem without either the element in measure 3 or the one in measure 4 - somehow, it's the interaction between these that causes the issue. Still, the direction element at the end of measure 1 seems to be the real key, I think, since that is the case we normally we not create ourselves (the original MusicXML file in #67001: Crash on opening file with apparently invalid note anchored textline came from Sibelius, I believe).