Wha on earth has someone done to my starter gear hole?

1982 1100 Spectre

I’m replacing a leaking alternator gasket and I pull off the starter reduction gear and see this mess. It looks like the case broke and someone blobbed it back together. I’m pretty worried about it, I’ve dumped thousands in parts on this bike already.

Whilst not pretty that repair will easily hold up to the job.
The damage to the starter idler boss is fairly common and was due to a PO spinning the starter motor with the generator cover removed.

for a weld on a casting that looks pretty good, whoever did that knew what they were doing. I wouldn't worry about it at all.