The attempt to delete a bond by the eraser tool yields at times the erasing of the neighbor bond. The issue is relatively rare but becomes evident after some time. While the problem could occur in a very simple situation, its reliable reproduction is non trivial. A sequence of steps leading to a reproducible issue is shown in the attached figure (the numbers in the cycles in the first image represent the sequence of drawing the cycles by the cyclopentane-tool via bond sharing; if the bonds are drawn differently, the issue might not reproduce). The issue might be connected by a bug in a stack-like storage of some connectivity information; interestingly the issue is not reproducible if the deletion sequence of the four bonds is interrupted by exiting to another browser tab, for example.
