Bug report: "Use of uninitialized value $_ in print"

First, background. I encountered a bug on Debian Stretch, using this git version:

$ git --version git version 2.11.0

The bug is that in the midst of running

git -c interactive.diffFilter="git diff --word-diff --color" add --patch

and after having answered "y" to some patches and "n" to others, git suddenly spewed the following output:

Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 74. Stage this hunk [y,n,q,a,d,/,K,j,J,g,e,?]? n Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75. Use of uninitialized value $_ in print at /usr/lib/git-core/git-add--interactive line 1371, <STDIN> line 75.

I hope that this bug report can help the git core maintainers to either fix the problem upstream, or to co-ordinate a fix with the Debian git maintainer(s) if the bug does not exist upstream.

Thanks for the great DVCS :)

P.S. I am not subscribed to this mailing list, so please CC me in your reply if you want me to see it.