Part-to-part connections in BB causes connectivity issues in other views

[failiz]

Current Behaviour

When there is a part-to-part connection in the breadboard view, it is impossible to connect the two connectors in the schematic or PCB by dragging from one connector to the other.

Build: 0.9.10 in Windows

Steps to reproduce:

• Change to BB view and remove breadboard
• Add an Arduino UNO
• Add a resistor and rotate it 90 degrees
• Connect the top leg of the resistor, by moving it, to pin A0 in the Arduino like in the figure
• Change to the schematic view
• Try to connect the two connectors by pressing on one connector and releasing the mouse on the other connector.

Expected Behaviour

The connections are made

Notes

• This does not happen if you try using pins A5 or A4. The reason is that they have a bus and there are two connectors. In BB, the connectors are in different places, but in the schematic view they are stacked. Thus, the original connector is skipped but connects to the hidden one.
• This behaviour also happens in the PCB view. To reproduce it, you need to change to place the trace on the bottom view. In the top view, I think it happens something similar to the A4 or A5 (two connectors stacked).
• This was discovered by analyzing issue #3659. I think there is no bug in #3659, but there is a bug in the linked forum post: https://forum.fritzing.org/t/request-dragino-lora-shield-for-arduino/9137/6 (The file called Incorrect-connections-by-overlay-shield-on-arduino-Sketch.fzz (52.8 KB))

Cause

This is caused by the code that avoids self-connections (a wire cannot start and end at the same connector). This is in wire.cpp, from line 600. But the underlying reason is maybe that a direct connection creates connections between connections in ALL views.

[KjellMorgenstern]

Still an issue in 1.0.3.

Just retried this. The schematic view shows a ratsnest line. A schematic wire can still not be created, as reported, by trying to press a connector, then release the mouse on the other connector.

It is however possible to drag or double click the ratsnest line.

This behavior is inconsistent: If there is a wire between the parts in BB view, or the connector has a bus (as described in the OP), then a wire also can be created by click and drag from a connector to the other.