Re: [PATCH] run-command: encode signal death as a positive integer

Hi,

Jeff King wrote:

When a sub-command dies due to a signal, we encode the
signal number into the numeric exit status as "signal -
128".

[...]

So we have a negative value inside the code, but once it
passes across an exit() barrier, it looks positive (and any
code we receive from a sub-shell will have the positive
form).

[...]

Unfortunately, this means that when the "use_shell" option
is set, we need to be on the lookout for _both_ forms.

[...]

            for the callers that do care, we can make life
slightly easier by just using the consistent positive form.

Makes perfect sense.

 Documentation/technical/api-run-command.txt | 6 ++----
 editor.c                                    | 2 +-
 run-command.c                               | 2 +-
 3 files changed, 4 insertions(+), 6 deletions(-)

t/test-terminal.perl imitates the same logic.  It doesn't check for
anything other than whether the exit status is 0, but maybe it would
be worth squashing in the below as a futureproofing measure
nonetheless.

Aside from the launch_editor bugfix, the only observable effects of
the above patch I can find are some changed error messages:

	error: external filter cat failed -126
	-> error: external filter cat failed 130

	warning: svnrdump, returned -126
	-> warning: svnrdump, returned 130

Those messages are equally senseless before and after the patch, so
for what it's worth,
Reviewed-by: Jonathan Nieder <redacted>

Thanks.

diff --git i/t/test-terminal.perl w/t/test-terminal.perl
index 10172aee..1fb373f2 100755
--- i/t/test-terminal.perl
+++ w/t/test-terminal.perl

@@ -31,7 +31,7 @@ sub finish_child {
 	} elsif ($? & 127) {
 		my $code = $? & 127;
 		warn "died of signal $code";
-		return $code - 128;
+		return $code + 128;
 	} else {
 		return $? >> 8;
 	}