Ticket #6827: restrict_impl2.patch

M:\boost-dev\boost\iostreams\detail\

@@ -141 +141 @@
     template<typename Source>
     std::streamsize read(Source& src, char_type* s, std::streamsize n)
     {
         using namespace std;
         if (!open_)
             open(src, BOOST_IOS::in);
-        std::streamsize amt =
-            end_ != -1 ?
-                (std::min) (n, static_cast<std::streamsize>(end_ - pos_)) :
-                n;
+
+        std::streamsize amt(n);
+
+        if (end_ != -1)
+        {
+            boost::iostreams::stream_offset remaining(end_ - pos_);
+
+            if (remaining <= std::numeric_limits<std::streamsize>::max())
+                amt = (std::min)(n, static_cast<std::streamsize>(remaining));
+        }
+
         std::streamsize result = 
             iostreams::read(this->component(), src, s, amt);
         if (result != -1)
             pos_ += result;
         return result;
     }