Check for zero-length slices in `slice.equal`

1 files changed, 11 insertions, 0 deletions

diff --git a/core/slice/slice.odin b/core/slice/slice.odin
index 989fcc696..99ad15547 100644
--- a/core/slice/slice.odin
+++ b/core/slice/slice.odin
@@ -200,6 +200,17 @@ equal :: proc(a, b: $T/[]$E) -> bool where intrinsics.type_is_comparable(E) #no_
 		return false
 	}
 	when intrinsics.type_is_simple_compare(E) {
+		if len(a) == 0 {
+			// Empty slices are always equivalent to each other.
+			//
+			// This check is here in the event that a slice with a `data` of
+			// nil is compared against a slice with a non-nil `data` but a
+			// length of zero.
+			//
+			// In that case, `memory_compare` would return -1 or +1 because one
+			// of the pointers is nil.
+			return true
+		}
 		return runtime.memory_compare(raw_data(a), raw_data(b), len(a)*size_of(E)) == 0
 	} else {
 		for i in 0..<len(a) {