Re: [PATCH] http-backend: Don't infinite loop during die()

"Shawn O. Pearce" [off-list ref] writes:

If stdout has already been closed by the CGI and die() gets called,
the CGI will fail to write the "Status: 500 Internal Server Error" to
the pipe, which results in die() being called again (via safe_write).
This goes on in an infinite loop until the stack overflows and the
process is killed by SIGSEGV.

Instead set a flag on the first die() invocation and perform no
action during recursive die() calls.  This way failures to write the
error messages to the stdout pipe do not result in an infinite loop.

Hmm.  I would need something like this on top, but there must be a better
way.  Ideas?

-- >8 --
Subject: [PATCH] fixup! http-backend.c: Don't infinite loop

Now die_webcgi() actually can return during a recursive call into it,
causing

    http-backend.c:554: error: 'noreturn' function does return

Work it around with a somewhat ugly workaround.

Signed-off-by: Junio C Hamano <redacted>
---
 http-backend.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/http-backend.c b/http-backend.c
index f4d49b6..d3ec6f0 100644
--- a/http-backend.c
+++ b/http-backend.c

@@ -536,7 +536,7 @@ static void service_rpc(char *service_name)
 	strbuf_release(&buf);
 }
 
-static NORETURN void die_webcgi(const char *err, va_list params)
+static void die_webcgi(const char *err, va_list params)
 {
 	static int dead;
 

@@ -606,7 +606,7 @@ int main(int argc, char **argv)
 	int i;
 
 	git_extract_argv0_path(argv[0]);
-	set_die_routine(die_webcgi);
+	set_die_routine((void *)die_webcgi);
 
 	if (!method)
 		die("No REQUEST_METHOD from server");

-- 
1.7.0.3.435.g097f4