Subject: bug#38173: describe-variable: Also tell user *where* variable was changed

From: 積丹尼 Dan Jacobson <[email-masked]>
Date: Tue, 12 Nov 2019 10:45:21 +0800

OK, here is another example

    read-buffer-completion-ignore-case is a variable defined in ‘C source code’.
    Its value is t
    Original value was nil

It's like telling users "you transferred $123 from your bank account"
but not telling users who they transferred it to.