Fix S3BinaryCacheStore

It failed with

   AWS error uploading ‘6gaxphsyhg66mz0a00qghf9nqf7majs2.ls.xz’: Unable to parse ExceptionName: MissingContentLength Message: You must provide the Content-Length HTTP header.

possibly because the istringstream_nocopy introduced in
0d2ebb4373e509521f27a6e8f16bfd39d05b2188 doesn't supply the seek
method that the AWS library expects. So bring back the old version,
but only for S3BinaryCacheStore.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libutil/hash.cc b/src/libutil/hash.cc
index 49e781980f3a..81aced0fde16 100644
--- a/src/libutil/hash.cc
+++ b/src/libutil/hash.cc
@@ -106,7 +106,7 @@ Hash parseHash(HashType ht, const string & s)
         string s2(s, i * 2, 2);
         if (!isxdigit(s2[0]) || !isxdigit(s2[1]))
             throw BadHash(format("invalid hash ‘%1%’") % s);
-        istringstream_nocopy str(s2);
+        std::istringstream str(s2);
         int n;
         str >> std::hex >> n;
         hash.hash[i] = n;