bin/40617: [dM] mail(1) interrupt handling oddity

[der Mouse <mouse%Rodents-Montreal.ORG@localhost>]

>Number:         40617
>Category:       bin
>Synopsis:       [dM] mail(1) handles an interrupt oddly
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Feb 11 17:20:00 +0000 2009
>Originator:     der Mouse
>Release:        5.0_RC1 (also -current as of 2009-02-11)
>Organization:
        Dis-
>Environment:
        First noticed on ftp.netbsd.org, which (according to uname) was
        running 5.0_RC1 at the time; a correspondent reports, on
        2009-02-11, that -current has the same problem.
>Description:
        When sending mail, interrupting at the Subject: prompt behaves
        oddly: instead of echoing the interrupt character the way it
        usually does ("^C" in my case), it simply prints a newline (I
        think once I had it print nothing at all, but can't seem to
        reproduce that, so I may have been hallucinating).  Another
        interrupt is echoed normally and produces mail's usual
        "(Interrupt -- one more to kill letter)" message; a third
        interrupt does indeed kill the letter.

        There is historical basis for ignoring the first interrupt; on
        one of my 1.4T systems, the above description is accurate
        except that the interrupt at the Subject: prompt is echoed
        normally, same as the other two.
>How-To-Repeat:
        % mail destination
        Subject: 

        Type your interrupt character, notice it just prints a newline
        rather than echoing it normally.
>Fix:
        Unknown.  mail refers to SIGINT on 43 different lines, too many
        for me to try to trace them all; looking at the code
        surrounding the Subject: prompt didn't lead me obviously to any
        of them.  Since I currently have no machines running either
        5.0_RC1 or -current, I'm not in a position to diagnose this
        further at the moment.