Troubles on joining data and identifying specific fields via "joined fields" in QGIS

Question

I do have frequent crashes as soon as I try to select a subset of fields to be joined via layer properties / joins / joined fields checkboxes. joins of the same pair of tables without limiting fields according to my specific selection work well. crashes did also occur after specifying custom field name prefixes within the join dialog. both test were done with the target table opened.

My tests covered XLSX files and CSV files so far. I have been observing this problem unsing several versions (from 3.20 to 3.24) - right now I am on QGIS 3.24.0. is there anything I could do in order to avoid these crashes - any known workaround so FAR?

QGIS issues list at github doesn't show any corresponding results on the keywords 'join' 'crash' 'field' - so I am not sure whether or not I am the only one with that kind of problem.

• Matt: You can add any extra information such as your 'update' comment to your question. It will help readers to have all information in the same place.
• robert tuw: i just realized that my question was closed without providing valid reasoning. i have been providing a description of the specific circumstances of these crashes, the problem can be reproduced by following my steps - so why is it closed ???
• Matt: Good question. I have the same thought about various other posts. It is not fair to indiscriminately close questions without at least providing some feedback or advice about how to improve them, or a specfic reason for closing.
• robert tuw: totally agree - especially because this is a really annoying problem. right now I think it is related to the open attribute table wich is the join target. but the discussion is closed and tons of people will face the same thing and will be as confused as I am ...
• Matt: Can you provide some example data with which the problem can be reproduced?

Answer 1

This issue was reported in https://github.com/qgis/QGIS/issues/47921 and https://github.com/qgis/QGIS/issues/48380. This issue has been fixed in master, release-3_22 and release-3_24 branches; the fix will be available in the upcoming QGIS 3.24.3 and QGIS 3.22.7 and subsequent releases.

Answer 2

now, after several tests i am pretty sure that the problem of having crashes after trying to join data to a feature class table and additionally specifying fields as well as the field-prefixes: if you have the target table open/visible QGIS app crashes - if it is closed QGIS is not affected. i would highly appreciate comunity-comments on that - since, if I am right with my assumption that would be a serious bug.

Answer 3

You are correct; the crash only occurs if the target table is open at the time the join is created (good detective work, by the way!).

This appears to be a bug, and I have submitted a bug report at:

https://github.com/qgis/QGIS/issues/48380

• Andrea Giudiceandrea: The issue was already reported in github.com/qgis/QGIS/issues/47921 and fixed with github.com/qgis/QGIS/pull/48226
• robert tuw: thx for feedback - by the way i've got a minus one on "usefulness" for your comment. somehow surprising ;)