Angus Leeming wrote:
> Make the addPreview call conditional on "snippet" not being empty:
Thanks, Angus.
Actually, it's not that easy, unfortunately, since snippet is never empty. For
empty insets, it's '$ $'. A check for cell(0).empty() is better, but that
fails for nested empty insets, e.g. $\mbox{}$ as well as for empty arrays,
which both trigger the bug.
I didn't found a way yet to get the contents of a mathinset without any LaTeX
cruft. Even plaintext outputs "\mbox{}" and "\begin{array}...\end{array}".
Any ideas?
Apart from that, could somebody with python knowledge have a look at the
internal reasons of the bug, the calculation of the absurd frac value?
AFAICS, this is done in legacy_lyxpreview2ppm.py.
The relevant code is
ascent = string.atof(match.group(2)) + tp_ascent
descent = string.atof(match.group(3)) - tp_descent
frac = 0.5
if abs(ascent + descent) > 0.1:
frac = ascent / (ascent + descent)
metrics.write("Snippet %s %f\n" % (match.group(1), frac))
The absurd frac value is calculated from this entry in the log file:
Snippet 1 0 0 0
i.e., if ascent and descent are 0.
Thanks,
Jürgen
