I am not certain if this is a bug or a request to work around broken
mailers. I tried replying to a message today (with recent git) and got
an empty message. I looked at the json output for reply and it contains
the message but the content type is TEXT/PLAIN rather than
text/plain.

This seems to mean it doesn't match in notmuch-match-content-type
(notmuch-lib.el) called from notmuch-mua-get-quotable-parts (in
notmuch-mua.el); and so does not get included.

Making the match case-insensitive `fixed' the problem.

I don't know whether content-types are allowed  to be upper-case but I
seem to have several mails where they are. I am also not sure whether
the correct fix is in the emacs code, or in the cli reply format
(i.e. perhaps the reply format should lower-case the content-type).

Best wishes

Mark

PS Sorry Adam for the duplicate: I sent from a wrong address (my fault
this time)!