I dont think the "set a field value" tamper resolves this and it could be worth a module update -- Thinking back to #3, maybe this is different for non-CSV sources, but for a CSV source couldn't we compare the CSV columns to the mapped columns and not update the content value if the column was omitted?
If the column is present, but blank, I think that is different and feeds should update the content with empty values as it does now.
Maybe #3049832 that #7 mentioned could mitigate it in some instances, but I dont think feeds tamper's "set a field value" can set the field value to be whatever is currently stored in the content (just some arbitrary value you provide in the tamper ui). It also seems like a hack to something that should just work that way out of the box.
I can also confirm the issue. I have a feed set up to import CSV data, with an Explode tamper on a specific column.
When I import an empty or valid string it seems to work fine, but if I import a sheet that doesnt include the tampered column (I don't want to update items with an empty value), I get HTTP 500 during import and the same message as the reporter.
I agree this should be a fix put into the module instead of a custom code snippet.
mslaxmeter → created an issue.
mslaxmeter → created an issue.
I moved one of the fields outside of my fieldsets so I can confirm it is not the fieldsets/CSS affecting it.
mslaxmeter → created an issue.