on-demand branchname validity (while typing)

[extrawurst]

libgit2 exposes a helper function to check a branch name validity: https://libgit2.org/libgit2/#HEAD/group/branch/git_branch_name_is_valid

lets run this against the input before it gets confirmed.
this way we can give live feedback to the user whether the name is valid.

[extrawurst]

same for tag names: https://libgit2.org/libgit2/#HEAD/group/tag/git_tag_name_is_valid

[franciscod]

hello there! rust newcomer here. will take a shot at this :)

[extrawurst]

hello there! rust newcomer here. will take a shot at this :)

Very cool, welcome! Let me know when you need any help

[extrawurst]

requires upstream change first: rust-lang/git2-rs#714

[franciscod]

wip: rust-lang/git2-rs#715

[franciscod]

also wip: master...franciscod:wip_check_branch_name

(won't create PR until the one in git2-rs lands)

[extrawurst]

@franciscod congrats for the merge in git2-rs but it did not contain the same function for tags which we also wanted to cover in here :(

[franciscod]

Thanks! git_branch_name_is_valid is the only one that I implemented. Internally it also checks that it's a valid name for a reference. Do we need anything else?

[franciscod]

ah, for tags, missed that one! Well #759 is my work in progress for branches, I guess we could do branches first and then tags?

[extrawurst]

after rust-lang/git2-rs#734 we can at least go ahead with the branch validity check