How can I send a patch to libstdc++-v3 about a small mistake

[=?gb18030?B?0P3XqruqtvvXyA==?= <i@shuaitq.com>]

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Hello all

I found a small mistake while looking at the code of libstdc++-v3 on GitHub. link: gcc/libstdc++-v3 at master ¡¤ gcc-mirror/gcc (github.com). And the wiki of GitHub repo shows that pull requests sent to this repository will be ignored and should be contributed upstream instead.

So, I want to send a patch to upstream. But I have not contributed code before. I have no idea what I should do, and I have some questions below.

Should I subscribe to mailing lists like gcc-help, gcc-patches and libstdc++ before sending a patch?
Should I just send the patch to mailing list gcc-patches and libstdc++?
After I send the patch to mailing list, if there anyone will send email to me about the result or all I should do is wait a commit in git://gcc.gnu.org/git/gcc.git?
What else should I do? like testing, documentation changes. I think this is a small mistake fix, this is not needed.
Should I send patch email using git send-email rather than email website like Gmail?

If there is anything you think I should know, you can just write it in email or give me a link. I'm happy to know.

Thanks
Tianqiang Shuai