From 62b119e07f29fa8ca6926b1186fa3eb14cb4f481 Mon Sep 17 00:00:00 2001
From: Greg Alexander <gitgreg@galexander.org>
Date: Sun, 28 Jul 2019 22:26:55 -0400
Subject: [PATCH] Keep around a copy of the old dropbear.err so that it can be
 accessed after the server is re-started for a crash (to get easy access to
 the crash dump).

---
 jni/interface.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/jni/interface.c b/jni/interface.c
index dd1b6b1..54583d6 100644
--- a/jni/interface.c
+++ b/jni/interface.c
@@ -141,11 +141,15 @@ Java_org_galexander_sshd_SimpleSSHDService_start_1sshd(JNIEnv *env_,
 		char *argv[100] = { "sshd", NULL };
 		int argc = 1;
 		const char *logfn;
+		const char *logfn_old;
 		int logfd;
 		int retval;
 		int i;
 
 		logfn = conf_path_file("dropbear.err");
+		logfn_old = conf_path_file("dropbear.err.old");
+		unlink(logfn_old);
+		rename(logfn, logfn_old);
 		unlink(logfn);
 		logfd = open(logfn, O_CREAT|O_WRONLY, 0666);
 		if (logfd != -1) {