When using the natural layout algorithm with the fill-gaps option, a small
error (less than one) is introduced in windows' aspect ratio each time they are
enlarged due to floating-point roundoff.
Currently, the algorithm computes the width and height enlargement factors and
then attempts to enlarge in each of the four possible directions, repeating
until it can't enlarge any windows any further. Hence, this aspect ratio error
can be multiplied by up to four. Especially for small, long, and narrow
windows, this can result in a total error of greater than one by the end of
that loop iteration. If this occurs, on subsequent iterations the height
enlargement factor might then be computed as negative violating some of the
core assumptions of the algorithm and resulting in the loop iterating endlessly
until one of the window dimensions overflows, freezing the program for up to
To fix this, the height enlargement factor should be re-computed based on the
new width each time the window is enlarged, ensuring the error introduced in
the aspect ratio never exceeds one.