Sorry for being a bit terse in the two messages above. The reason we use the "junior_job" tag is precisely to motivate people to start contributing in small but useful ways, and your effort is much appreciated.
There are two ways to do code review:
through Mantis: just upload a patch as you have done above, and we can comment on it and, when it feels ready for merging, integrate it.
through github: while issues (bug reports) are disabled on the github ocaml repository ( https://github.com/ocaml/ocaml/ ), pull requests are accepted and can be reviewed and merged from the usual github interface.
You are free to use whichever of those systems have your personal preference (github used to be a second-class citizen used for an experiment only, but it is now the official development repository).
Since we are now using git as the version control for the official OCaml distribution repository, the easiest way to preserve authorship information for your patch is to send it in format that "git am" understands (that is, the output of "git format-patch"). This is done automatically by github if you use it, but it is of course also possible to upload a git-friendly patch here on Mantis. Otherwise, if you just upload a plain diff, a maintainer may commit it directly, marking you in the commit message as patch author. In this latter case, it is helpful if you can indicate in the comments somewhere the name under which you would like to be credited.
There are more information on how to contribute to OCaml in the CONTRIBUTING.md document: