RE: Column line spacing changed with 2.18

[Javier Ruiz-Alma]

>>From: David Kastrup 

>>It would appear to be at least correlated to
<URL:https://code.google.com/p/lilypond/issues/detail?id=3483>,
>>version 2.17.24 (it is easy to do
>>git revert 6e8698dcb9a9b9a98d8b1a644c84fcb737f99bdc
>>in order to experiment with this).

>>It is not clear to me what the exact relation is, however.  It may be that
the problem just surfaces with different sizes.  The change results in
pango_font_description_set_size receiving numbers that are rounded rather
than truncated, so ?>>pango_font_description_set_size will receive a number
that may be larger by up to 0.5 than the exact number.  I would think that
this does not affect the overall problem but will likely change the cases
where those are most prevalent.

The problem bars are set to \abs-fontsize #12.   In trying to find a fix for
2.18.2, would it be worth testing other values close to 12 that minimize
rounding error?  What is the base value?