Backport r67975: #4759: fix segfault in bytearray.translate(x, None).
diff --git a/Lib/test/test_bytes.py b/Lib/test/test_bytes.py
index 36defb8..00aee02 100644
--- a/Lib/test/test_bytes.py
+++ b/Lib/test/test_bytes.py
@@ -872,11 +872,19 @@
 
     def test_translate(self):
         b = b'hello'
+        ba = bytearray(b)
         rosetta = bytearray(range(0, 256))
         rosetta[ord('o')] = ord('e')
         c = b.translate(rosetta, b'l')
         self.assertEqual(b, b'hello')
         self.assertEqual(c, b'hee')
+        c = ba.translate(rosetta, b'l')
+        self.assertEqual(ba, b'hello')
+        self.assertEqual(c, b'hee')
+        c = b.translate(None, b'e')
+        self.assertEqual(c, b'hllo')
+        self.assertRaises(TypeError, b.translate, b'a'*256, None)
+        self.assertRaises(TypeError, ba.translate, b'a'*256, None)
 
     def test_split_bytearray(self):
         self.assertEqual(b'a b'.split(memoryview(b' ')), [b'a', b'b'])
diff --git a/Misc/NEWS b/Misc/NEWS
index b75ddf9..3bea977 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,8 @@
 Core and Builtins
 -----------------
 
+- Issue #4759: fix a segfault for bytearray.translate(x, None).
+
 - Added test case to ensure attempts to read from a file opened for writing
   fail.
 
diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index d75eb53..56071a0 100644
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -1465,6 +1465,7 @@
     if (delobj != NULL) {
         if (_getbuffer(delobj, &vdel) < 0) {
             result = NULL;
+            delobj = NULL;  /* don't try to release vdel buffer on exit */
             goto done;
         }
     }