bug#27668: 26.0.50; Crash with display-line-numbers t

[Robert Pluim <rpluim@gmail.com>]

Robert Pluim <rpluim@gmail.com> writes:

> Eli Zaretskii <eliz@gnu.org> writes:
>
>>> From: Robert Pluim <rpluim@gmail.com>
>>> Would you like me to try an unoptimised build? CFLAGS=-O0 -ggdb or
>>> similar?
>>
>> It cannot hurt, so please do.  Maybe this will give some valuable
>> hints.  (Please use "-gdwarf-4 -g3" instead of -ggdb, it should
>> provide a better debug info.)  Btw, I already did an optimized build,
>> but was unable to reproduce the problem there as well.
>>
>
> I'll try that next, I think you're on the right track.
>

Two more data points:

- building with CFLAGS='-gdwarf-4 -g3 -O0' results in an emacs that I
can't get to crash
- building with default CFLAGS='-g3 -O2', but using the previous
system compiler also results in an emacs that I can't crash. That one
reports:

$ gcc-4.9 -v
Using built-in specs.
COLLECT_GCC=gcc-4.9
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.9/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.9.3-13ubuntu2' --with-bugurl=file:///usr/share/doc/gcc-4.9/README.Bugs --enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.9 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.9 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.9-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.9.3 (Ubuntu 4.9.3-13ubuntu2) 

Regards

Robert