Re: [PATCH] run-command: encode signal death as a positive integer
From: Junio C Hamano <hidden>
Date: 2016-06-15 22:55:40
Jeff King [off-list ref] writes:
On Sat, Jan 05, 2013 at 09:03:16AM -0500, Jeff King wrote: ... The downside is that callers of run_command can no longer differentiate between a signal received directly by the sub-process, and one propagated. However, no caller currently cares, and since we already optimize out some calls to the shell under the hood, that distinction is not something that should be relied upon by callers. Signed-off-by: Jeff King <redacted> ---
Very nicely explained. Thanks.
quoted hunk
Documentation/technical/api-run-command.txt | 6 ++---- editor.c | 2 +- run-command.c | 2 +- 3 files changed, 4 insertions(+), 6 deletions(-)diff --git a/Documentation/technical/api-run-command.txt b/Documentation/technical/api-run-command.txt index f18b4f4..5d7d7f2 100644 --- a/Documentation/technical/api-run-command.txt +++ b/Documentation/technical/api-run-command.txt@@ -55,10 +55,8 @@ The functions above do the following: non-zero. . If the program terminated due to a signal, then the return value is the - signal number - 128, ie. it is negative and so indicates an unusual - condition; a diagnostic is printed. This return value can be passed to - exit(2), which will report the same code to the parent process that a - POSIX shell's $? would report for a program that died from the signal. + signal number + 128, ie. the same value that a POSIX shell's $? would + report. A diagnostic is printed. `start_async`::diff --git a/editor.c b/editor.c index 065a7ab..27bdecd 100644 --- a/editor.c +++ b/editor.c@@ -51,7 +51,7 @@ int launch_editor(const char *path, struct strbuf *buffer, const char *const *en sigchain_push(SIGINT, SIG_IGN); sigchain_push(SIGQUIT, SIG_IGN); ret = finish_command(&p); - sig = ret + 128; + sig = ret - 128; sigchain_pop(SIGINT); sigchain_pop(SIGQUIT); if (sig == SIGINT || sig == SIGQUIT)diff --git a/run-command.c b/run-command.c index 757f263..cfb7274 100644 --- a/run-command.c +++ b/run-command.c@@ -249,7 +249,7 @@ static int wait_or_whine(pid_t pid, const char *argv0) * mimics the exit code that a POSIX shell would report for * a program that died from this signal. */ - code -= 128; + code += 128; } else if (WIFEXITED(status)) { code = WEXITSTATUS(status); /*