`combine_supp` throwing an error when columns exist in the supp that do not correspond to a record in core dataset

[LiamHobby]

combine_supp function throws an error when there are IDVARVAL values in the supp dataset that do not map to those in the core dataset.

The intent of the function in this case is to return the merged dataset with the message "Not all rows of the supp were merged. The following rows are missing...", however the function errors instead.

Look into the cause of this bug and rewrite test cases to capture the two paths i.e., all rows merged vs. not all rows merged.

Link to textfile containing R code demonstrating the issue:
combine_supp_bug.txt

[sadchla-codes]

It seems like the bug is coming from combine_supp_join() calling stop() instead of emitting a message when it detects non-matching IDVARVAL rows, so the function errors out instead of returning the merged dataset. @bms63 do you mind if take a stab at this one?

[bms63]

go for it!!