# [PATCH v2] diff-highlight: exit when a pipe is broken 3 messages from 2014-11-04 to 2014-11-04. Participants: John Szakmeister, Jeff King, Junio C Hamano. Thread: https://gitlist.dev/t/37877 ## John Szakmeister, 2014-11-04 20:01 Subject: [PATCH v2] diff-highlight: exit when a pipe is broken Message-ID: <1415131272-89441-1-git-send-email-john@szakmeister.net> URL: https://gitlist.dev/e/1415131272-89441-1-git-send-email-john%40szakmeister.net ``` While using diff-highlight with other tools, I have discovered that Python ignores SIGPIPE by default. Unfortunately, this also means that tools attempting to launch a pager under Python--and don't realize this is happening--means that the subprocess inherits this setting. In this case, it means diff-highlight will be launched with SIGPIPE being ignored. Let's work with those broken scripts by restoring the default SIGPIPE handler. Signed-off-by: John Szakmeister --- Incorporates feedback from Jeff King and now we just restore the default signal handler using the correct case of 'DEFAULT'. contrib/diff-highlight/diff-highlight | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/contrib/diff-highlight/diff-highlight b/contrib/diff-highlight/diff-highlight index c4404d4..69a652e 100755 --- a/contrib/diff-highlight/diff-highlight +++ b/contrib/diff-highlight/diff-highlight @@ -14,6 +14,10 @@ my @removed; my @added; my $in_hunk; +# Some scripts may not realize that SIGPIPE is being ignored when launching the +# pager--for instance scripts written in Python. +$SIG{PIPE} = 'DEFAULT'; + while (<>) { if (!$in_hunk) { print; -- 2.0.1 ``` ## Jeff King, 2014-11-04 20:09 Subject: Re: [PATCH v2] diff-highlight: exit when a pipe is broken Message-ID: <20141104200932.GA15149@peff.net> URL: https://gitlist.dev/e/20141104200932.GA15149%40peff.net In-Reply-To: <1415131272-89441-1-git-send-email-john@szakmeister.net> ``` On Tue, Nov 04, 2014 at 03:01:12PM -0500, John Szakmeister wrote: > While using diff-highlight with other tools, I have discovered that Python > ignores SIGPIPE by default. Unfortunately, this also means that tools > attempting to launch a pager under Python--and don't realize this is > happening--means that the subprocess inherits this setting. In this case, it > means diff-highlight will be launched with SIGPIPE being ignored. Let's work > with those broken scripts by restoring the default SIGPIPE handler. > > Signed-off-by: John Szakmeister > --- > Incorporates feedback from Jeff King and now we just restore the default signal > handler using the correct case of 'DEFAULT'. Thanks, this version looks much simpler. :) Acked-by: Jeff King -Peff ``` ## Junio C Hamano, 2014-11-04 20:52 Subject: Re: [PATCH v2] diff-highlight: exit when a pipe is broken Message-ID: URL: https://gitlist.dev/e/xmqqtx2epu1i.fsf%40gitster.dls.corp.google.com In-Reply-To: <20141104200932.GA15149@peff.net> ``` Jeff King writes: > On Tue, Nov 04, 2014 at 03:01:12PM -0500, John Szakmeister wrote: > >> While using diff-highlight with other tools, I have discovered that Python >> ignores SIGPIPE by default. Unfortunately, this also means that tools >> attempting to launch a pager under Python--and don't realize this is >> happening--means that the subprocess inherits this setting. In this case, it >> means diff-highlight will be launched with SIGPIPE being ignored. Let's work >> with those broken scripts by restoring the default SIGPIPE handler. >> >> Signed-off-by: John Szakmeister >> --- >> Incorporates feedback from Jeff King and now we just restore the default signal >> handler using the correct case of 'DEFAULT'. > > Thanks, this version looks much simpler. :) > > Acked-by: Jeff King Thanks, both. The patch looks good. Will queue. ```