bugfix: ngx.pipe: fixed a segfault when error_log is configured with syslog.

spacewander · thibaultcha · commit afeeb84b0840 · 2019-03-09T18:30:12.000-06:00
Fix openresty/lua-resty-shell#7.
diff --git a/src/ngx_http_lua_pipe.c b/src/ngx_http_lua_pipe.c
@@ -703,8 +703,8 @@ ngx_http_lua_ffi_pipe_spawn(ngx_http_lua_ffi_pipe_proc_t *proc,
                           "pipe fd");
         }
 
-        errlog_fd = ngx_cycle->log->file->fd;
-        if (errlog_fd == STDERR_FILENO) {
+        if (ngx_cycle->log->file && ngx_cycle->log->file->fd == STDERR_FILENO) {
+            errlog_fd = ngx_cycle->log->file->fd;
             temp_errlog_fd = dup(errlog_fd);
 
             if (temp_errlog_fd == -1) {

Original file line number	Diff line number	Diff line change
`@@ -703,8 +703,8 @@ ngx_http_lua_ffi_pipe_spawn(ngx_http_lua_ffi_pipe_proc_t *proc,`
`703`	`703`	`"pipe fd");`
`704`	`704`	`}`
`705`	`705`
`706`		`- errlog_fd = ngx_cycle->log->file->fd;`
`707`		`- if (errlog_fd == STDERR_FILENO) {`
	`706`	`+ if (ngx_cycle->log->file && ngx_cycle->log->file->fd == STDERR_FILENO) {`
	`707`	`+ errlog_fd = ngx_cycle->log->file->fd;`
`708`	`708`	`temp_errlog_fd = dup(errlog_fd);`
`709`	`709`
`710`	`710`	`if (temp_errlog_fd == -1) {`