when running a select statement with an inner join where the secondary field is non-existent, we get a panic. this commit fixes that.
see [fb-766](https://molecula.atlassian.net/browse/FB-766) for more information.
If a field doesn't exist, looking up that field produces a nil,
and querying the name of a nil field fails. Don't do that. Instead,
just use the name you're looking it up by.
We could in theory return an error here, but we already handle
nonexistent fields elsewhere and checking this when we already have
checks for it seems unnecessary, I think?
Also, we add a test for this. The test is over in server/grpc_test.go
because we have infrastructure there for testing the SQL server
functionality, and you can't actually write reasonable self-contained
tests for the SQL stuff because it has no way to create a working
server.
i used this script, a little clunky but it got the job done
```bash
for file in `find . -type f -print | grep '\.go'`; do
sed '1,/^\/\/ limitations under the License.$/d' $file > $file.tmp;
result=`cat $file.tmp`
if [[ result != "" ]]; then
gofmt $file.tmp &> /dev/null;
if [[ $? == 0 ]]; then
mv $file.tmp $file && gofmt -w $file;
else
rm $file.tmp;
fi
else
rm $file.tmp;
fi
done
```
Attributes are unmaintained and unused.
They have become more of a liability than a benefit.
This change eliminates them from the codebase.
The only user-visible change (assuming that attrs are not used) is that the attrs field will no longer appear in row JSON.
We want to distinguish different *kinds* of GroupCounts, so we're
making the GroupCounts parent object track its type so we can keep that
correct.
Adding this to protobuf, etc, then creates some weird behaviors
because sometimes we expect []GroupCount, and sometimes we expect
*GroupCounts. This implies changes to test cases. Also, the
changes to test cases imply that some test cases are probably now
wrong; for instance, they're expecting a "sum" column, equal to zero,
when no sum was requested.
We try to make the encoder handle a []*GroupCount gotten from another
node without panicing, and avoid breaking the semantics of the existing
messages, renumbering messages or components, etc.
Since a previous version, the `.Groups` member has been privatized,
and the `.Get()` convenience accessor has been renamed `.Groups()`
and is now used consistently in a way that should reduce the risk
of nil pointers causing crashes. Also, NewGroupCounts is used in
a couple more places.
