From 9a717a319a8bab854e1f69da652216f167c8009d Mon Sep 17 00:00:00 2001
From: carbotaniuman <41451839+carbotaniuman@users.noreply.github.com>
Date: Tue, 29 Dec 2020 22:17:15 -0600
Subject: [PATCH 1/3] use unsigned abs to avoid overflow

---
 vm/src/sliceable.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/vm/src/sliceable.rs b/vm/src/sliceable.rs
index 1af55078b..d6cf9a462 100644
--- a/vm/src/sliceable.rs
+++ b/vm/src/sliceable.rs
@@ -391,7 +391,7 @@ impl TryFromObject for SequenceIndex {
 // Use PySliceableSequence::wrap_index for implementors
 pub(crate) fn wrap_index(p: isize, len: usize) -> Option<usize> {
     let neg = p.is_negative();
-    let p = p.abs().to_usize()?;
+    let p = p.wrapping_abs() as usize;
     if neg {
         len.checked_sub(p)
     } else if p >= len {

From eecebef0e02e8cf3bbf8be6441d4307c024bc0cf Mon Sep 17 00:00:00 2001
From: carbotaniuman <41451839+carbotaniuman@users.noreply.github.com>
Date: Wed, 30 Dec 2020 10:56:00 -0600
Subject: [PATCH 2/3] Add test

---
 extra_tests/snippets/builtin_slice.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/extra_tests/snippets/builtin_slice.py b/extra_tests/snippets/builtin_slice.py
index 6c2dd847b..89ef5dba9 100644
--- a/extra_tests/snippets/builtin_slice.py
+++ b/extra_tests/snippets/builtin_slice.py
@@ -1,4 +1,5 @@
 from testutils import assert_raises
+import sys
 
 a = []
 assert a[:] == []
@@ -129,3 +130,5 @@ def test_all_slices():
 
 
 test_all_slices()
+
+assert_raises(IndexError, lambda: b[::0], _msg='bytearray index out of range')
\ No newline at end of file

From 3ca003a94d64ff1a97a3af368fff3bc18b9d8948 Mon Sep 17 00:00:00 2001
From: carbotaniuman <41451839+carbotaniuman@users.noreply.github.com>
Date: Wed, 30 Dec 2020 11:53:49 -0600
Subject: [PATCH 3/3] Fix test

---
 extra_tests/snippets/builtin_slice.py | 3 ---
 extra_tests/snippets/bytearray.py     | 7 ++++++-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/extra_tests/snippets/builtin_slice.py b/extra_tests/snippets/builtin_slice.py
index 89ef5dba9..6c2dd847b 100644
--- a/extra_tests/snippets/builtin_slice.py
+++ b/extra_tests/snippets/builtin_slice.py
@@ -1,5 +1,4 @@
 from testutils import assert_raises
-import sys
 
 a = []
 assert a[:] == []
@@ -130,5 +129,3 @@ def test_all_slices():
 
 
 test_all_slices()
-
-assert_raises(IndexError, lambda: b[::0], _msg='bytearray index out of range')
\ No newline at end of file
diff --git a/extra_tests/snippets/bytearray.py b/extra_tests/snippets/bytearray.py
index 0abfc0127..3550149a3 100644
--- a/extra_tests/snippets/bytearray.py
+++ b/extra_tests/snippets/bytearray.py
@@ -1,5 +1,6 @@
 from testutils import assert_raises
 import pickle
+import sys
 
 # new
 assert bytearray([1, 2, 3])
@@ -753,4 +754,8 @@ b = pickle.loads(pickle.dumps(a, 4))
 assert type(a) == type(b)
 assert a.x == b.x
 assert a.y == b.y
-assert a == b
\ No newline at end of file
+assert a == b
+
+a = bytearray()
+for i in range(-1, 2, 1):
+    assert_raises(IndexError, lambda: a[-sys.maxsize - i], _msg='bytearray index out of range')
\ No newline at end of file