Fix reverse step bugs

Fixes google#36
jayvdb · Sep 24, 2020 · f56846a · f56846a
1 parent 1bef76e
commit f56846a
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/sre_yield/__init__.py b/sre_yield/__init__.py
@@ -90,6 +90,8 @@ def slice_indices(slice_obj, size):
             start = size - 1
     else:
         start = _adjust_index(start, size, raise_index_error=False)
+        if step < 0:
+            start = min(start, size - 1)
 
     if stop is None:
         if step > 0:
@@ -98,6 +100,8 @@ def slice_indices(slice_obj, size):
             stop = -1
     else:
         stop = _adjust_index(stop, size, raise_index_error=False)
+        if step < 0:
+            stop = max(stop, -1)
 
     return (start, stop, step)