Ensure body is consumed only once

Fixes: #846
Signed-off-by: Mathieu Parent <math.parent@gmail.com>

vcr/util.py

@@ -89,9 +89,28 @@ def compose(*functions):
     return composed
 
 
+def _is_nonsequence_iterator(obj):
+    return hasattr(obj, "__iter__") and not isinstance(
+        obj,
+        (bytearray, bytes, dict, list, str),
+    )
+
+
 def read_body(request):
     if hasattr(request.body, "read"):
         return request.body.read()
+    if _is_nonsequence_iterator(request.body):
+        body = list(request.body)
+        if body:
+            if isinstance(body[0], str):
+                return "".join(body).encode("utf-8")
+            elif isinstance(body[0], (bytes, bytearray)):
+                return b"".join(body)
+            elif isinstance(body[0], int):
+                return bytes(body)
+            else:
+                raise ValueError(f"Body type {type(body[0])} not supported")
+        return b""
     return request.body