Crash by changing time signature in a measure in Continuous view when a glissando extends from the previous measure

You can observe:

. First point:
With the same initial attached file: test file.mscz, you can get a crash at step #5 (before Save) by toggle in "Page View"

. Second point:
With this file: test file Page View.mscz and with steps:
1) Load the file above
2) Add a glissando between the two notes
3) Change time signature in measure2
4) Toggle in "Continuous View"

Result: the glissando extends to the end of the file

So, from what I see by going back in time, this issue is a two-stages rocket.

Chronologically, the first issue/stage occurs on February 18, 2015, and leads to the two results described in comment #2 , ie:
- the first one: crash when switching from Continuous View to Page View
- the second one: glissando extending to the end of the file when switching from Page View to Continuous View. Knowing we can see the same behavior, to a lesser extent, in Page View under certain conditions of layout.

- This nightly works: e7591d1
- Not this one: 802fa8a

There are three commits between these two nigthlies. So, I presume this one might be a good candidate? https://github.com/musescore/MuseScore/pull/1536/files

The second issue/ stage appears on July 8, 2015, and leads to the result reported initially, ie crash by saving the score, with deletion of all data.

- With this nightly, there is no crash: e5f3119
- With this one, there is: ef4429a

Except an oblivion, I see only two commits between these two nightlies, which seem - the first or second ? - to be the triggers of this fatal outcome.
Ie: - https://github.com/musescore/MuseScore/commit/ef4429accf37fc3d6abfd1c1d…, and
- https://github.com/musescore/MuseScore/commit/858ddb25e8d3da6cc59bbc4c9…

EDIT: in another way, I see this also (but probably not related at all?) : https://github.com/musescore/MuseScore/commit/a9cec566a40704a425f649fcd…