Changing the connector pane of a subVI requires relinking to the subVI in all callers. Until we relink (right-click...), the subVI is bleached and the caller broken.
When refactoring old code, subVIs often contain odd connector panes and one might want to change to a more typical pattern (e.g. 4-2-2-4), and reassign connectors to established policies (e.g. error in/out at the bottom corners). Also, sometimes there was poor planning and we need just one more connector terminal.
Currently, relinking to a subVI clears all "subVI node setup" settings. This is unexpected and I suggest that these settings are retained instead.
I was working on some very old code (originally from LabVIEW 4.0 :o), and there was a single instance of an interactive subVI that was set to show the front panel when called and close afterwards ((in the subVI node setup of the caller, not in the VI itself). This subVI was interactive and required user interaction to complete. It had some odd connector pane (four horizontal terminals all the way across the icon, top as input and botton as output) and I wanted to change it to the standard 4-2-2-4 pattern. After changing the pattern, I did some switcheroo on the connectors, correctly rewired in the caller, rebuilt the app and deployed it to the PC controlling an instrument. (I could not test run locally because it required the presence of the instrument)
Bam! Triggering the subVI call no longer showed the front panel and since the caller required the subVI to return before continuing, everything was locked up. I had to kill the build executable via task manager. Now the guessing game started, trying to figure out why the app would lock up. Since I also did a few minor changes elsewhere, It took me a while before realizing that I should maybe look at the "subVI node setup". Sure enough, all settings were cleared. These settings were retained during 20 years of version upgrades and I did not expect them to change behind he scene and without warning :D.
Anyone can easily verify that relinking to a subVI will clear all settings in the subVI node setup. Would anyone expect that? Probably not!
Relinking to a subVI should retain the existing "subVI node setup" settings.
The existing settings are most likely also appropriate after the connector pattern has changed. This is the expected bahavior. There is no reason to clear these settings. Thanks for your votes!