If you fail to select all columns in a table, and then sort on a column, you lose the data relationship across colums (or across rows, same thing). Writer needs either a sort warning or some sort of protection, so that the data relationship maintains integrity if only one column is selected for sorting. I rate it major because I've lost many hours work that I will need to redo, because when I sorted on a table column I failed to select all of the columns.
I think a trivial solution would be to simply place a text warning in the sort check box. Something like: ""WARNING!: ARE YOU SURE YOU WANT TO PRIOR SELECT ONE COLUMN ONLY? DOING SO WILL DESTROY DATA RELATIONSHIP ACROSS ROWS!" It's the selection of columns prior to the check box that needs to amount to more than one column.
Created attachment 154996 [details]
Sort check box
Just saying that a solution could be to extend the text string from "Sort Criteria" to "Sort Criteria ---- WARNING: ...."
Created attachment 155004 [details]
Extend sorting range in Calc
Calc asks whether the selection should be extended, which sounds like the better choice than a warning. The dialog might be standardized somewhat.
I think the issue is, will everyone realise that in most cases with Writer certainly, they need to extend the range. If that is not realised, then it does feel like the text should amount to a warning. The suggestion that I've made, by adding more text to the string "Sort Criteria" in the sort check box, is meant to be a stopgap and simply executed solution until a better one is created. If I thought I could provide the technical solution, I'd adopt the bug, but unfortunately I'm not a coder.
If we can detect that not the whole table is selected (and show a warning then), we could also provide means to extend it. So let's go with the Calc solution and show a confirmation box with Keep, Extend, and Cancel (focused).