GNU Emacs 25.2.2 (x86_64-pc-linux-gnu, GTK+ Version 3.22.16)
of 2017-07-11, modified by Debian

1] Function `delete-indentation' does not preserve point. The attached
patch fixes that for joining lines both forward and backward.

2] Also included is a wrapper function, `my-join-lines' that I'd like to
propose be included in emacs.

2.1] The wrapper function adds the ability to:

2.1.1] Act on regions;

2..1.2] Accept a numeric prefix argument for the number of lines to join
in either direction.

2.2] Lines of the wrapper function annotated on the right with the
string `; ┃' are only necessary if the proposed patch to function
`delete-indentation' is rejected.

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