CVS commit: src/bin/sh

["Robert Elz" <kre%netbsd.org@localhost>]

Module Name:    src
Committed By:   kre
Date:           Thu Apr 25 03:54:10 UTC 2019

Modified Files:
        src/bin/sh: trap.c

Log Message:
Better interactive SIGINT handling (when a trap is set), and other
cleanups to the trap code.   No longer silently ignore attempts to
do anything other than set SIGKILL or SIGSTOP to the default ('-")
state.   Don't include those in trap or trap -p output (the former
because they cannot be other than in default state, so simply aren't
included, the latter because it is pointless) but do list them
when requested with trap -p SIG.

Interactive mode SIGINT traps are now run ASAP, rather than after
a command has been entered (so the sequence ^C \n is no longer needed
to generate one).   Further, when trapped, in interactive mode,
while waiting for a user command, a SIGINT acts (aside from the
trap being run) just like when not trapped, aborts the command being
entered (rather than leaving it, which it did when libedit was in use)
prints a new prompt, and starts again (which is what should happen.)

Traps other than SIGINT (which has always been handled special in
interactive mode) are unaffected by this change, as are SIGINT traps
in non-interactive shells.    Or that is the intent anyway.

Fix an in_dotrap ref count bug (was never being decremented... that
was inserted in a place never executed) (relatively harmless) and
add/improve some trap/signal related DEBUG mode tracing.


To generate a diff of this commit:
cvs rdiff -u -r1.51 -r1.52 src/bin/sh/trap.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.