immutable: fix detection of truncated shares to take into account the fieldsize ...

diff --git a/src/allmydata/immutable/layout.py b/src/allmydata/immutable/layout.py
index 16b91c5926c6fd676cc598e0c283b60f5e37f485..1f5de5ab0db3d360570892d0f192595f2e1f54fd 100644 (file)
--- a/src/allmydata/immutable/layout.py
+++ b/src/allmydata/immutable/layout.py
@@ -371,8 +371,8 @@ class ReadBucketProxy:
         offset = self._offsets['uri_extension']
         d = self._read(offset, self._fieldsize)
         def _got_length(data):
-            if len(data) != 4:
-                raise LayoutInvalid("not enough bytes to encode URI length -- %d" % (len(data),))
+            if len(data) != self._fieldsize:
+                raise LayoutInvalid("not enough bytes to encode URI length -- should be %d bytes long, not %d " % (self._fieldsize, len(data),))
             length = struct.unpack(self._fieldstruct, data)[0]
             if length >= 2**31:
                 # URI extension blocks are around 419 bytes long, so this must be corrupted.