bug in bashbug script shipped with bash 5.2.15

[Ti Strga]

The bug likely got checked in earlier than 5.2.15, that's just what I
happened to be running when I ran into this.

$ declare -p BASH_VERSINFO
declare -ar BASH_VERSINFO=([0]="5" [1]="2" [2]="15" [3]="3"
[4]="release" [5]="x86_64-pc-cygwin")

$ bashbug
/usr/bin/bashbug: line 135: [: missing `]'
/usr/bin/bashbug: line 137: [: missing `]'

{at this point I'm inside my $EDITOR, and exited without making changes}

/usr/bin/bashbug: You have not changed the subject from the default.
/usr/bin/bashbug: Please use a more descriptive subject header.
/usr/bin/bashbug: Type `y' to give up, and lose your bug report;
/usr/bin/bashbug: type `n' to re-enter the editor.
/usr/bin/bashbug: Do you want to give up? y
$


The relevant lines are in a series of tests trying to find the correct
editor executable:

    .....
    elif [ -x /usr/bin/xemacs ]; then
        DEFEDITOR=xemacs
    elif [ -x /usr/bin/vim; then         <----
        DEFEDITOR=vim
    elif [ -x /usr/bin/gvim; then         <----
        DEFEDITOR=gvim
    elif [ -x /usr/bin/nano ]; then
    .....