resty: more improvements.

* made ngx.exit() an alias of os.exit().
* made the exit status code right for the wrapper process.
* require at least ngx_lua 0.9.12 to prevent memory bugs in older
  versions.
* suppressed a debugging output line.

util/mirror-tarballs

@@ -335,7 +335,7 @@ mv openresty-drizzle-nginx-module-* drizzle-nginx-module-$ver || exit 1
 
 #################################
 
-ver=0.9.12rc1
+ver=0.9.12rc2
 $root/util/get-tarball "https://github.com/openresty/lua-nginx-module/tarball/v$ver" -O lua-nginx-module-$ver.tar.gz || exit 1
 tar -xzf lua-nginx-module-$ver.tar.gz || exit 1
 mv openresty-lua-nginx-module-* ngx_lua-$ver || exit 1

util/resty

@@ -76,7 +76,7 @@ if (!@nameservers) {
     push @nameservers, "8.8.8.8", "8.8.4.4";
 }
 
-warn "@nameservers\n";
+#warn "@nameservers\n";
 
 my $prefix_dir = tempdir(CLEANUP => 1);
 #warn "prefix dir: $prefix_dir\n";
@@ -187,6 +187,7 @@ $lua_package_path_config
         ngx.flush = function (...) return stdout:flush() end
         -- we cannot close stdout here due to a bug in Lua:
         ngx.eof = function (...) return true end
+        ngx.exit = os.exit
     ';
 
     init_worker_by_lua '
@@ -196,12 +197,19 @@ $lua_package_path_config
         local function handle_err(err)
             if err then
                 err = string.gsub(err, "^init_worker_by_lua:%d+: ", "")
-                stderr:write(err)
+                stderr:write(err, "\\\\n")
             end
             return exit(1)
         end
 
         local ok, err = pcall(function ()
+            if not ngx.config
+               or not ngx.config.ngx_lua_version
+               or ngx.config.ngx_lua_version < 9011
+            then
+                error("at least ngx_lua 0.9.12 is required")
+            end
+
 $loader
             -- print("calling timer.at...")
             local ok, err = ngx.timer.at(0, function ()
@@ -256,7 +264,11 @@ if ($pid == 0) {  # child process
 } else {
     $child_pid = $pid;
     waitpid($child_pid, 0);
-    exit($? || 0);
+    my $rc = 0;
+    if (defined $?) {
+        $rc = ($? >> 8);
+    }
+    exit($rc);
 }
 
 sub usage {

util/ver

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 main_ver=1.7.4
-minor_ver=1rc1.1
+minor_ver=1rc1.2
 version=$main_ver.$minor_ver
 echo $version