From fbf68c860b190c04c0e906272041c0cfc9bad560 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Thu, 30 Jan 2020 17:09:29 +1100
Subject: [PATCH] HAL_SITL: fixed bitmask error on storage erase

---
 libraries/AP_HAL_SITL/Storage.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libraries/AP_HAL_SITL/Storage.cpp b/libraries/AP_HAL_SITL/Storage.cpp
index 50131c9a97..2ce4d4af1f 100644
--- a/libraries/AP_HAL_SITL/Storage.cpp
+++ b/libraries/AP_HAL_SITL/Storage.cpp
@@ -69,7 +69,10 @@ void Storage::_storage_open(void)
 */
 void Storage::_mark_dirty(uint16_t loc, uint16_t length)
 {
-    uint16_t end = loc + length;
+    if (length == 0) {
+        return;
+    }
+    uint16_t end = loc + length - 1;
     for (uint16_t line=loc>>STORAGE_LINE_SHIFT;
          line <= end>>STORAGE_LINE_SHIFT;
          line++) {