Wt-1985. Fixes required by new packing tests:

Specifying 'u' as a format can result in a 'U' format appearing in
an index. The pack/unpack routines need to understand 'U'.

1 files changed, 10 insertions, 9 deletions

diff --git a/lang/python/wiredtiger/packing.py b/lang/python/wiredtiger/packing.py
index b6f474face8..bda5820a543 100644
--- a/lang/python/wiredtiger/packing.py
+++ b/lang/python/wiredtiger/packing.py
@@ -87,17 +87,18 @@ def unpack(fmt, s):
                 size = 1
             s = s[size:]
             # Note: no value, don't increment i
-        elif f in 'Ssu':
+        elif f in 'SsUu':
             if not havesize:
                 if f == 's':
                     size = 1
                 elif f == 'S':
                     size = s.find('\0')
-                elif f == 'u':
-                    if offset == len(fmt) - 1:
-                        size = len(s)
-                    else:
-                        size, s = unpack_int(s)
+                elif f == 'u' and offset == len(fmt) - 1:
+                    size = len(s)
+                else:
+                    # Note: 'U' is used internally, and may be exposed to us.
+                    # It indicates that the size is always stored.
+                    size, s = unpack_int(s)
             result.append(s[:size])
             if f == 'S' and not havesize:
                 size += 1
@@ -132,7 +133,7 @@ def __pack_iter_fmt(fmt, values):
     for offset, havesize, size, char in __unpack_iter_fmt(fmt):
         if char == 'x':  # padding no value
             yield offset, havesize, size, char, None
-        elif char in 'Ssut':
+        elif char in 'SsUut':
             yield offset, havesize, size, char, values[index]
             index += 1
         else:            # integral type
@@ -157,7 +158,7 @@ def pack(fmt, *values):
             else:
                 result += '\0' * size
             # Note: no value, don't increment i
-        elif f in 'Ssu':
+        elif f in 'SsUu':
             if f == 'S' and '\0' in val:
                 l = val.find('\0')
             else:
@@ -167,7 +168,7 @@ def pack(fmt, *values):
                     l = size
             elif f == 's':
                 havesize = size = 1
-            elif f == 'u' and offset != len(fmt) - 1:
+            elif (f == 'u' and offset != len(fmt) - 1) or f == 'U':
                 result += pack_int(l)
             if type(val) is unicode and f in 'Ss':
                 result += str(val[:l])