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

[Matthias Kilian]

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):


commit 6d28aebbaaab1be9961a00bf15a1ef93acb91e30
Author: Neil Puttock <address@hidden>
Date:   Mon Sep 6 22:49:28 2010 +0100

    Fix metronome alignment.
    
    Don't align on KeySignature unless explicitly requested via
    'break-align-symbols and make order of 'break-align-symbols
    significant.
    
    * remove `key-signature' from 'break-align-symbols
    
    * acknowledge break_alignment, and set this as X-parent
      instead of break_aligned, but only if found break_aligned
      is visible
    
    * add regression test to test ordering
    
    * tweak existing test to reflect change in default for
      'break-align-symbols

[...]


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.

diff --git a/lily/metronome-engraver.cc b/lily/metronome-engraver.cc
index 0a41fc9..e34c0ad 100644
--- a/lily/metronome-engraver.cc
+++ b/lily/metronome-engraver.cc
@@ -95,7 +95,10 @@ Metronome_mark_engraver::acknowledge_break_aligned 
(Grob_info info)
           && safe_is_member (g->get_property ("break-align-symbol"),
                              text_->get_property ("break-align-symbols"))
           && Item::break_visible (g))
-    support_ = g;
+    {
+      support_ = g;
+      text_->set_parent (g, X_AXIS);
+    }
 }
 
 void

Ciao,
        Kili