shutil: copyfileobj(): Support file objects without readinto() method.

shutil/shutil.py

@@ -9,6 +9,7 @@ def rmtree(top):
         os.rmdir(path)
 
 def copyfileobj(src, dest, length=512):
+    if hasattr(src, "readinto"):
         buf = bytearray(length)
         while True:
             sz = src.readinto(buf)
@@ -19,3 +20,9 @@ def copyfileobj(src, dest, length=512):
             else:
                 b = memoryview(buf)[:sz]
                 dest.write(b)
+    else:
+        while True:
+            buf = src.read(length)
+            if not buf:
+                break
+            dest.write(buf)