Merge pull request #1362 from sporksmith/tpp-slice

sporksmith · web-flow · commit c41f16b81a5e · 2021-05-16T12:43:00.000-05:00
TypedPluginPtr::slice : allow empty slice at end of range
diff --git a/src/main/host/syscall_types.rs b/src/main/host/syscall_types.rs
@@ -228,8 +228,11 @@ impl<T> TypedPluginPtr<T> {
             Bound::Excluded(s) => s + 1,
             Bound::Unbounded => 0,
         };
+        assert!(included_start <= excluded_end);
         assert!(excluded_end <= self.count);
-        assert!(included_start < self.count);
+        // `<=` rather than `<`, to allow empty slice at end of ptr.
+        // e.g. `assert_eq!(&[1,2,3][3..3], &[])` passes.
+        assert!(included_start <= self.count);
         TypedPluginPtr {
             base: PluginPtr {
                 ptr: c::PluginPtr {
