2.19.81 aborts on many .ly files when compiled with gcc8 -Wp,-D_GLIBCXX_ASSERTIONS

[Mamoru TASAKA]

Hello:

As previously reported on this mailing list:
http://lists.gnu.org/archive/html/bug-lilypond/2018-04/msg00038.html

There was a downstream bug report on Fedora (rawhide) as
https://bugzilla.redhat.com/show_bug.cgi?id=1568274 that

lilypond 2.19.81 , when compiled with gcc8 -Wp,-D_GLIBCXX_ASSERTIONS , abort()s 
on many .ly files.
-Wp,-D_GLIBCXX_ASSERTIONS adds some brief range checks for std::vector and 
Fedora 28 and above uses
this compilation flags by default:
https://fedoraproject.org/wiki/Changes/HardeningFlags28#Detailed_Description

For example, $ lilypond lilypond-2.19.81/input/regression/rest-pitched-beam.ly 
abort()s like the attached.
And the attached proposal patch should fix this issue. Please review this.

Regards,
Mamoru TASAKA <address@hidden>

gdb-lilypond.log.txt
Description: Text document

rest-pitched-beam.ly
Description: Text Data

0001-Fix-out-of-bounds-access-detected-by-D_GLIBCXX_ASSER.patch
Description: Text Data