=== modified file 'src/StoreIOBuffer.h'
--- src/StoreIOBuffer.h	2012-09-01 14:38:36 +0000
+++ src/StoreIOBuffer.h	2012-12-28 15:34:13 +0000
@@ -45,7 +45,11 @@
 
     StoreIOBuffer(size_t aLength, int64_t anOffset, char *someData) :
             length (aLength), offset (anOffset), data (someData) {
-        flags.error = 0;
+        flags.error = false;
+        if (length < 0) {
+            flags.error = true;
+            length = 0;
+        }
     }
 
     /* Create a StoreIOBuffer from a MemBuf and offset */
@@ -54,14 +58,14 @@
             length(aMemBuf->contentSize()),
             offset (anOffset),
             data(aMemBuf->content()) {
-        flags.error = 0;
+        flags.error = false;
     }
 
     StoreIOBuffer(MemBuf *aMemBuf, int64_t anOffset, size_t anLength) :
             length(anLength),
             offset (anOffset),
             data(aMemBuf->content()) {
-        flags.error = 0;
+        flags.error = false;
     }
 
     Range<int64_t> range() const {
@@ -74,7 +78,7 @@
     }
 
     struct {
-        unsigned error:1;
+        bool error:1;
     } flags;
     size_t length;
     int64_t offset;

=== modified file 'src/store_client.cc'
--- src/store_client.cc	2012-09-18 21:05:32 +0000
+++ src/store_client.cc	2012-12-28 15:36:02 +0000
@@ -146,14 +146,12 @@
 void
 store_client::callback(ssize_t sz, bool error)
 {
-    StoreIOBuffer result(sz, 0 ,copyInto.data);
+    // result.flags.error will be set to true if sz < 0
+    StoreIOBuffer result(sz, 0, copyInto.data);
 
-    if (sz < 0) {
-        result.flags.error = 1;
-        result.length = 0;
-    } else {
-        result.flags.error = error ? 1 : 0;
-    }
+    // but we may have received an error; in that case, override.
+    if (error)
+        result.flags.error = true;
 
     result.offset = cmp_offset;
     assert(_callback.pending());