Rover: prevent log corruption during log creation

APMrover2/GCS_Mavlink.pde

@@ -1885,7 +1885,7 @@ void GCS_MAVLINK::handleMessage(mavlink_message_t* msg)
 static void mavlink_delay_cb()
 {
     static uint32_t last_1hz, last_50hz, last_5s;
-    if (!gcs[0].initialised) return;
+    if (!gcs[0].initialised || in_mavlink_delay) return;
 
     in_mavlink_delay = true;
 

APMrover2/Log.pde

@@ -568,7 +568,9 @@ static void Log_Read(uint16_t log_num, uint16_t start_page, uint16_t end_page)
 // start a new log
 static void start_logging() 
 {
+    in_mavlink_delay = true;
     DataFlash.StartNewLog();
+    in_mavlink_delay = false;
     DataFlash.Log_Write_Message_P(PSTR(FIRMWARE_STRING));
 
     // write system identifier as well if available