Slowness and error in OMEdit error when resizing

[massimo ceraolo]

In some cases resizing of a model in diagram view is very slow.
In the latest nightly build it even creates a huge error message.

I've tested the behaviour using two different versions:
v1.9.4-dev.beta1-101
v1.9.4-dev.beta2-99

Steps to reproduce (using EHPT.mo):
1) load EHPT in OMEdit
2) select FullVehicles|PSecu1
3) using the mouse slightly resize the icon of the large connector EHPT.SupportModels.Conn d
4) OMEdit hangs for a few seconds (both the above versions), then (only the above beta2 version) issues, in the message browser, the huge message (13915 lines) reported in ErrorMessage.txt.

I wonder why resizing is so slow. From my viewpoint it could be an operation carried out directly by OMEdit, without OMC interaction, so I expect it to be very fast.
Whatever the mechanism, the final user expects resizing to be fast since it appears to be just a graphical operation.

In the latest beta the additional issue of the reported error message has appeared.

For me the slowness makes the priority of this ticket "high"; the error message in the beta requires a "critical" priority. That's why I choose the latter.