* leak fix for debian #250583

apt-pkg/contrib/mmap.cc

@@ -155,9 +155,9 @@ DynamicMMap::DynamicMMap(FileFd &F,unsigned long Flags,unsigned long WorkSpace)
    unsigned long EndOfFile = Fd->Size();
    if (EndOfFile > WorkSpace)
       WorkSpace = EndOfFile;
-   else
+   else if(WorkSpace > 0)
    {
-      Fd->Seek(WorkSpace);
+      Fd->Seek(WorkSpace - 1);
       char C = 0;
       Fd->Write(&C,sizeof(C));
    }