Bug in feedback node copy and paste

[Thoric]

I've not seen this posted anywhere, a bug in the copy paste behaviour of feedback nodes between block diagrams can cause a LabVIEW crash.

To replicate:

1. Create two New VIs.
2. Create a while loop with a boolean constant to the conditional terminal in each block diagram.
3. In one while loop, place a feedback terminal and move the initialiser out one loop (so that it sits on the left hand edge of the while loop)
4. (This step may be unnecessary) Wire an increment primitive to the terminals of the feedback node
5. Select the feedback node and the increment primitive, and drag and drop the code into the while loop of the second VI (see below)

6. Note that the feedback node in the second VI has no initialiser terminal. If you attempt to run, or recompile, this second VI, LabVIEW (2009 SP1) crashes.

I have tested this is in 2009 SP1 only.

[FraggerFox]

I checked this out in LV2010.

Seems this issue is fixed in the 2010 version, I get the initialize terminal after copying it on other BD.

I also checked the Bug Fixes link, it seems there were many changes related to the feedback node, but this particular issue fix is not listed.

[Thoric]

I've just tried this in the LV 2011 SP1 and it crashed, so they must have broken it again!

[Thoric]

I also just tried it in 2010 SP1 on a colleague's PC and it crashed there too. You seem to have the only stable version FraggerFox!

[Thoric]

Fragger, were you using Drag and Drop to copy the feedback node? Don't use copy and paste, the bug only occurs when dragging from one block diagram to the other with the mouse.

[FraggerFox]

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@Thoric wrote:

Fragger, were you using Drag and Drop to copy the feedback node? Don't use copy and paste, the bug only occurs when dragging from one block diagram to the other with the mouse.

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I dragged and dropped, didnt copy paste. I am using 2010 without SP1.

[Thoric]

In 2010 (with SP1), the drag and drop creates a feedback node without an initialiser terminal, and then crashes LabVIEW if you try to recompile or run that VI. Does your VI show no signs of an issue? What happens when you CTRL+Run (recompile) it?

[FraggerFox]

I checked with another PC having LV2009, it caused LabVIEW to crash.

I checked with yet another PC having just LV2010 (without SP1) installed, it worked.

Is anyone with LV2010 able to reproduce this?

[Thoric]

So, so far it crashes 2009 SP1, 2010 SP1, 2011 SP1, and it works on 2010 (no service pack).

It also crashes on another version of LabVIEW which can't be discussed in the public forums

[Wart]

Crashes in 2011 with no service pack when I click run.

When I dragged and dropped to the second VI the initilization terminal had the marching ants where it should be, but no actual terminal showed up.