Re: issue 1464 (was: a plea to new contributors)

[Graham Percival]

On Sat, Jan 01, 2011 at 08:14:36PM +0100, Matthias Kilian wrote:
> On Sat, Jan 01, 2011 at 02:10:04PM +0100, Matthias Kilian wrote:
> > I don't know why gdb doesn't find paper-column.hh, but anyaway...
> > it looks like Item::get_column() returns NULL, because its parent's
> > get_column() returns NULL (I checked that the parent on the X_AXIS
> > itself is not NULL).
> 
> Bisected to this one (cc'd Neil):

Fantastic!  Bisecting is one of the most useful, yet also
time-consuming, parts of fixing regressions.

> I tried the diff below, which `fixed' the segfault, but it may be
> completely wrong (I'm currently not familiar with the LilyPond code
> at all). Unfortunately, I don't have a new enough ImageMagick on my
> system, so I can't run the regression tests.

Sorry, my fault.  You can run the regtest comparison is you revert
49dc60e9 , or just remove "-dissimilarity-threshold" from
scripts/build/output-distance.py


Anyway, this patch works fine in the regtest comparison, so I've
uploaded it to reitveld for wider review.

Cheers,
- Graham