CG: add info about spacing from e-mail

diff --git a/Documentation/contributor/programming-work.itexi b/Documentation/contributor/programming-work.itexi
index 593e4563ba2ff13f56fabf780cef03567500cc9a..e64fa1673ae6b6242671746e8f4a1d9d0518ab87 100644 (file)
--- a/Documentation/contributor/programming-work.itexi
+++ b/Documentation/contributor/programming-work.itexi
@@ -1679,6 +1679,16 @@ We create lots of extra grobs (eg. a BarNumber at every bar line) but
 most of them are not drawn.  See the break-visibility property in
 item-interface.
 
+Here is another e-mail exchange.  Janek Warchoł asked for a starting point
+to fixing 1301 (change clef colliding with notes).  Neil Puttock replied:
+
+The clef is on a loose column (it floats before the head), so the
+first place I'd look would be lily/spacing-loose-columns.cc (and
+possibly lily/spacing-determine-loose-columns.cc).
+I'd guess the problem is the way loose columns are spaced between
+other columns: in this snippet, the columns for the quaver and tuplet
+minim are so close together that the clef's column gets dumped on top
+of the quaver (since it's loose, it doesn't influence the spacing).
 
 @node Info from Han-Wen email
 @subsection Info from Han-Wen email