From b63e974014d2f04f2dd5dbaab6f54f5e2136182d Mon Sep 17 00:00:00 2001
From: Pat Hickey <pat@moreproductive.org>
Date: Wed, 2 Sep 2020 13:39:32 -0700
Subject: [PATCH] code review fixes

---
 crates/wiggle/src/lib.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/crates/wiggle/src/lib.rs b/crates/wiggle/src/lib.rs
index 9c36c274f3..3e4e4c97ea 100644
--- a/crates/wiggle/src/lib.rs
+++ b/crates/wiggle/src/lib.rs
@@ -449,7 +449,7 @@ impl<'a, T> GuestPtr<'a, [T]> {
         self.pointer.0
     }
 
-    /// For slices, returns the length of the slice, in units.
+    /// For slices, returns the length of the slice, in elements.
     pub fn len(&self) -> u32 {
         self.pointer.1
     }
@@ -552,6 +552,9 @@ impl<'a, T> GuestPtr<'a, [T]> {
     }
 
     pub fn get_range(&self, r: std::ops::Range<u32>) -> Option<GuestPtr<'a, [T]>> {
+        if r.end < r.start {
+            return None;
+        }
         let range_length = r.end - r.start;
         if r.start <= self.len() && r.end <= self.len() {
             Some(GuestPtr::new(