When you add a point to an existing path, the expectation is that the shape of the path is "exactly" maintained. From a geometrical point of view, I suppose this is always possible (i.e. there always exist a solution in which the additional node is added but do not change the shape of the path, rounding errors and similar excepted).
Indeed, Inkscape usually fulfills the expectations. However, I just run into an example in which this does not work. In this case, the addition substantially modifies the original path, even causing one of the other nodes to move around.
To reproduce:
- open the attached file
- you will see a short path (e nodes) resembling a wave (they are actually two identical one on top of each other, so one can serve as a reference); there is also a vertical grey line, also to serve as a reference.
- select the "edit path" tool and double click on the "wave" somewhere in the vicinity of the vertical line.
- this will add a node in the position in which you double clicked, but will also noticeably modify the shape of the wave, and cause the middle node to move from its original position
Is this a bug in the algorithm the calculates the new path with the added node?
I'm using Inkscape 0.48.5 r10040.
Sorry, I marked this as "security vulnerability" by mistake.