CouchDB _find responses could have a warning key

[fschndr]

I recently messed around with _find and indexes. I accidentally produced a query with an miss matching index.
The error returned by ScanDoc() is Iterator is closed
Err() gives me Unexpected key: warning

I popped the query into my GUI REST client and the warning looks like this:

{
	"warning": "no matching index found, create an index to optimize query time",
	"docs": [
		{
...

For now this is the only warning in mango queries:
http:https://docs.couchdb.org/en/2.0.0/api/database/find.html#creating-selector-expressions

https://github.com/apache/couchdb/blob/f4c6113808d1809469df9c8be9d2f83ef399f064/src/mango/src/mango_httpd.erl#L235

I guess it would be good to expect possible warnings and let them surface anyhow. Maybe store them in a warning type - so you could retrieve it like Err().

Kind Regards

Fabian

[flimzy]

Thank you for the bug report. I believe the problem is now solved. Please let me know if you discover otherwise!