Re: [PATCH] completion: fix incorrect bash/zsh string equality check

"Robert Estelle via GitGitGadget" [off-list ref] writes:

    This fixes an error in contrib/completion/git-completion.bash caused by
    the incorrect use of == (vs. single =) inside a basic [/test command.
    Double-equals == should only be used with the extended [[ comparison.

Curious.  

Would it be equally a valid fix to use "=" instead of "==", or would
that change the meaning?  This is a bash-only piece of code, so use
of [[ ... ]] is not technically incorrect, but if the basic [] works
well enough with "=", we should prefer that.

Thanks.