Avoid stomping on flags during content properties encoding.

1 files changed, 14 insertions, 9 deletions

diff --git a/librabbitmq/codegen.py b/librabbitmq/codegen.py
index 9f6cde0..0967119 100644
--- a/librabbitmq/codegen.py
+++ b/librabbitmq/codegen.py
@@ -329,15 +329,20 @@ int amqp_encode_properties(uint16_t class_id,
      similarity of structure between classes */
   amqp_flags_t flags = * (amqp_flags_t *) decoded; /* cheating! */
 
-  do {
-    amqp_flags_t remainder = flags >> 16;
-    uint16_t partial_flags = flags & 0xFFFE;
-    if (remainder != 0) { partial_flags |= 1; }
-    E_16(encoded, offset, partial_flags);
-    offset += 2;
-    flags = remainder;
-  } while (flags != 0);
-
+  {
+    /* We take a copy of flags to avoid destroying it, as it is used
+       in the autogenerated code below. */
+    amqp_flags_t remaining_flags = flags;
+    do {
+      amqp_flags_t remainder = remaining_flags >> 16;
+      uint16_t partial_flags = remaining_flags & 0xFFFE;
+      if (remainder != 0) { partial_flags |= 1; }
+      E_16(encoded, offset, partial_flags);
+      offset += 2;
+      remaining_flags = remainder;
+    } while (remaining_flags != 0);
+  }
+  
   switch (class_id) {"""
     for c in spec.allClasses(): genEncodeProperties(c)
     print """    default: return -ENOENT;