Question about open-source

Hello,

I contributed to a fairly popular Rust crate on GitHub, but right before merging my PR, the maintainer copied my commits into a different branch (under his name and commit messages), closed my PR without merging, but merged his branch as a separate PR. Essentially, he made it look like he wrote the code himself but as far as I can tell it's verbatim what I wrote.

Is this normal? Am I wrong to be upset?

Thanks!