Adding upstream version 1.8.2.3.upstream/1.8.2.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3443 insertions, 0 deletions

diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
new file mode 100644
index 0000000..4f12349
--- /dev/null
+++ b/apt-pkg/contrib/fileutl.cc
@@ -0,0 +1,3443 @@
+// -*- mode: cpp; mode: fold -*-
+// Description								/*{{{*/
+/* ######################################################################
+   
+   File Utilities
+   
+   CopyFile - Buffered copy of a single file
+   GetLock - dpkg compatible lock file manipulation (fcntl)
+   
+   Most of this source is placed in the Public Domain, do with it what 
+   you will
+   It was originally written by Jason Gunthorpe <jgg@debian.org>.
+   FileFd gzip support added by Martin Pitt <martin.pitt@canonical.com>
+   
+   The exception is RunScripts() it is under the GPLv2
+
+   ##################################################################### */
+									/*}}}*/
+// Include Files							/*{{{*/
+#include <config.h>
+
+#include <apt-pkg/aptconfiguration.h>
+#include <apt-pkg/configuration.h>
+#include <apt-pkg/error.h>
+#include <apt-pkg/fileutl.h>
+#include <apt-pkg/macros.h>
+#include <apt-pkg/pkgsystem.h>
+#include <apt-pkg/sptr.h>
+#include <apt-pkg/strutl.h>
+
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <iostream>
+#include <string>
+#include <vector>
+#include <ctype.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <glob.h>
+#include <grp.h>
+#include <pwd.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <sys/select.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <memory>
+#include <set>
+
+#ifdef HAVE_ZLIB
+#include <zlib.h>
+#endif
+#ifdef HAVE_BZ2
+#include <bzlib.h>
+#endif
+#ifdef HAVE_LZMA
+#include <lzma.h>
+#endif
+#ifdef HAVE_LZ4
+#include <lz4frame.h>
+#endif
+#ifdef HAVE_ZSTD
+#include <zstd.h>
+#endif
+#ifdef HAVE_SYSTEMD
+#include <systemd/sd-bus.h>
+#endif
+#include <endian.h>
+#include <stdint.h>
+
+#if __gnu_linux__
+#include <sys/prctl.h>
+#endif
+
+#include <apti18n.h>
+									/*}}}*/
+
+using namespace std;
+
+/* Should be a multiple of the common page size (4096) */
+static constexpr unsigned long long APT_BUFFER_SIZE = 64 * 1024;
+
+// RunScripts - Run a set of scripts from a configuration subtree	/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool RunScripts(const char *Cnf)
+{
+   Configuration::Item const *Opts = _config->Tree(Cnf);
+   if (Opts == 0 || Opts->Child == 0)
+      return true;
+   Opts = Opts->Child;
+
+   // Fork for running the system calls
+   pid_t Child = ExecFork();
+   
+   // This is the child
+   if (Child == 0)
+   {
+      if (_system != nullptr && _system->IsLocked() == true && (stringcasecmp(Cnf, "dpkg::post-invoke") == 0 || stringcasecmp(Cnf, "dpkg::pre-invoke") == 0))
+	 setenv("DPKG_FRONTEND_LOCKED", "true", 1);
+      if (_config->FindDir("DPkg::Chroot-Directory","/") != "/") 
+      {
+         std::cerr << "Chrooting into " 
+                   << _config->FindDir("DPkg::Chroot-Directory") 
+                   << std::endl;
+         if (chroot(_config->FindDir("DPkg::Chroot-Directory","/").c_str()) != 0)
+            _exit(100);
+      }
+
+      if (chdir("/tmp/") != 0)
+	 _exit(100);
+	 
+      unsigned int Count = 1;
+      for (; Opts != 0; Opts = Opts->Next, Count++)
+      {
+	 if (Opts->Value.empty() == true)
+	    continue;
+
+         if(_config->FindB("Debug::RunScripts", false) == true)
+            std::clog << "Running external script: '"
+                      << Opts->Value << "'" << std::endl;
+
+	 if (system(Opts->Value.c_str()) != 0)
+	    _exit(100+Count);
+      }
+      _exit(0);
+   }      
+
+   // Wait for the child
+   int Status = 0;
+   while (waitpid(Child,&Status,0) != Child)
+   {
+      if (errno == EINTR)
+	 continue;
+      return _error->Errno("waitpid","Couldn't wait for subprocess");
+   }
+
+   // Restore sig int/quit
+   signal(SIGQUIT,SIG_DFL);
+   signal(SIGINT,SIG_DFL);   
+
+   // Check for an error code.
+   if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
+   {
+      unsigned int Count = WEXITSTATUS(Status);
+      if (Count > 100)
+      {
+	 Count -= 100;
+	 for (; Opts != 0 && Count != 1; Opts = Opts->Next, Count--);
+	 _error->Error("Problem executing scripts %s '%s'",Cnf,Opts->Value.c_str());
+      }
+      
+      return _error->Error("Sub-process returned an error code");
+   }
+   
+   return true;
+}
+									/*}}}*/
+
+// CopyFile - Buffered copy of a file					/*{{{*/
+// ---------------------------------------------------------------------
+/* The caller is expected to set things so that failure causes erasure */
+bool CopyFile(FileFd &From,FileFd &To)
+{
+   if (From.IsOpen() == false || To.IsOpen() == false ||
+	 From.Failed() == true || To.Failed() == true)
+      return false;
+
+   // Buffered copy between fds
+   constexpr size_t BufSize = APT_BUFFER_SIZE;
+   std::unique_ptr<unsigned char[]> Buf(new unsigned char[BufSize]);
+   unsigned long long ToRead = 0;
+   do {
+      if (From.Read(Buf.get(),BufSize, &ToRead) == false ||
+	  To.Write(Buf.get(),ToRead) == false)
+	 return false;
+   } while (ToRead != 0);
+
+   return true;
+}
+									/*}}}*/
+bool RemoveFileAt(char const * const Function, int const dirfd, std::string const &FileName)/*{{{*/
+{
+   if (FileName == "/dev/null")
+      return true;
+   errno = 0;
+   if (unlinkat(dirfd, FileName.c_str(), 0) != 0)
+   {
+      if (errno == ENOENT)
+	 return true;
+
+      return _error->WarningE(Function,_("Problem unlinking the file %s"), FileName.c_str());
+   }
+   return true;
+}
+									/*}}}*/
+bool RemoveFile(char const * const Function, std::string const &FileName)/*{{{*/
+{
+   if (FileName == "/dev/null")
+      return true;
+   errno = 0;
+   if (unlink(FileName.c_str()) != 0)
+   {
+      if (errno == ENOENT)
+	 return true;
+
+      return _error->WarningE(Function,_("Problem unlinking the file %s"), FileName.c_str());
+   }
+   return true;
+}
+									/*}}}*/
+// GetLock - Gets a lock file						/*{{{*/
+// ---------------------------------------------------------------------
+/* This will create an empty file of the given name and lock it. Once this
+   is done all other calls to GetLock in any other process will fail with
+   -1. The return result is the fd of the file, the call should call
+   close at some time. */
+int GetLock(string File,bool Errors)
+{
+   // GetLock() is used in aptitude on directories with public-write access
+   // Use O_NOFOLLOW here to prevent symlink traversal attacks
+   int FD = open(File.c_str(),O_RDWR | O_CREAT | O_NOFOLLOW,0640);
+   if (FD < 0)
+   {
+      // Read only .. can't have locking problems there.
+      if (errno == EROFS)
+      {
+	 _error->Warning(_("Not using locking for read only lock file %s"),File.c_str());
+	 return dup(0);       // Need something for the caller to close
+      }
+      
+      if (Errors == true)
+	 _error->Errno("open",_("Could not open lock file %s"),File.c_str());
+
+      // Feh.. We do this to distinguish the lock vs open case..
+      errno = EPERM;
+      return -1;
+   }
+   SetCloseExec(FD,true);
+      
+   // Acquire a write lock
+   struct flock fl;
+   fl.l_type = F_WRLCK;
+   fl.l_whence = SEEK_SET;
+   fl.l_start = 0;
+   fl.l_len = 0;
+   if (fcntl(FD,F_SETLK,&fl) == -1)
+   {
+      // always close to not leak resources
+      int Tmp = errno;
+      close(FD);
+      errno = Tmp;
+
+      if (errno == ENOLCK)
+      {
+	 _error->Warning(_("Not using locking for nfs mounted lock file %s"),File.c_str());
+	 return dup(0);       // Need something for the caller to close	 
+      }
+  
+      if (Errors == true)
+	 _error->Errno("open",_("Could not get lock %s"),File.c_str());
+      
+      return -1;
+   }
+
+   return FD;
+}
+									/*}}}*/
+// FileExists - Check if a file exists					/*{{{*/
+// ---------------------------------------------------------------------
+/* Beware: Directories are also files! */
+bool FileExists(string File)
+{
+   struct stat Buf;
+   if (stat(File.c_str(),&Buf) != 0)
+      return false;
+   return true;
+}
+									/*}}}*/
+// RealFileExists - Check if a file exists and if it is really a file	/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool RealFileExists(string File)
+{
+   struct stat Buf;
+   if (stat(File.c_str(),&Buf) != 0)
+      return false;
+   return ((Buf.st_mode & S_IFREG) != 0);
+}
+									/*}}}*/
+// DirectoryExists - Check if a directory exists and is really one	/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool DirectoryExists(string const &Path)
+{
+   struct stat Buf;
+   if (stat(Path.c_str(),&Buf) != 0)
+      return false;
+   return ((Buf.st_mode & S_IFDIR) != 0);
+}
+									/*}}}*/
+// CreateDirectory - poor man's mkdir -p guarded by a parent directory	/*{{{*/
+// ---------------------------------------------------------------------
+/* This method will create all directories needed for path in good old
+   mkdir -p style but refuses to do this if Parent is not a prefix of
+   this Path. Example: /var/cache/ and /var/cache/apt/archives are given,
+   so it will create apt/archives if /var/cache exists - on the other
+   hand if the parent is /var/lib the creation will fail as this path
+   is not a parent of the path to be generated. */
+bool CreateDirectory(string const &Parent, string const &Path)
+{
+   if (Parent.empty() == true || Path.empty() == true)
+      return false;
+
+   if (DirectoryExists(Path) == true)
+      return true;
+
+   if (DirectoryExists(Parent) == false)
+      return false;
+
+   // we are not going to create directories "into the blue"
+   if (Path.compare(0, Parent.length(), Parent) != 0)
+      return false;
+
+   vector<string> const dirs = VectorizeString(Path.substr(Parent.size()), '/');
+   string progress = Parent;
+   for (vector<string>::const_iterator d = dirs.begin(); d != dirs.end(); ++d)
+   {
+      if (d->empty() == true)
+	 continue;
+
+      progress.append("/").append(*d);
+      if (DirectoryExists(progress) == true)
+	 continue;
+
+      if (mkdir(progress.c_str(), 0755) != 0)
+	 return false;
+   }
+   return true;
+}
+									/*}}}*/
+// CreateAPTDirectoryIfNeeded - ensure that the given directory exists		/*{{{*/
+// ---------------------------------------------------------------------
+/* a small wrapper around CreateDirectory to check if it exists and to
+   remove the trailing "/apt/" from the parent directory if needed */
+bool CreateAPTDirectoryIfNeeded(string const &Parent, string const &Path)
+{
+   if (DirectoryExists(Path) == true)
+      return true;
+
+   size_t const len = Parent.size();
+   if (len > 5 && Parent.find("/apt/", len - 6, 5) == len - 5)
+   {
+      if (CreateDirectory(Parent.substr(0,len-5), Path) == true)
+	 return true;
+   }
+   else if (CreateDirectory(Parent, Path) == true)
+      return true;
+
+   return false;
+}
+									/*}}}*/
+// GetListOfFilesInDir - returns a vector of files in the given dir	/*{{{*/
+// ---------------------------------------------------------------------
+/* If an extension is given only files with this extension are included
+   in the returned vector, otherwise every "normal" file is included. */
+std::vector<string> GetListOfFilesInDir(string const &Dir, string const &Ext,
+					bool const &SortList, bool const &AllowNoExt)
+{
+   std::vector<string> ext;
+   ext.reserve(2);
+   if (Ext.empty() == false)
+      ext.push_back(Ext);
+   if (AllowNoExt == true && ext.empty() == false)
+      ext.push_back("");
+   return GetListOfFilesInDir(Dir, ext, SortList);
+}
+std::vector<string> GetListOfFilesInDir(string const &Dir, std::vector<string> const &Ext,
+					bool const &SortList)
+{
+   // Attention debuggers: need to be set with the environment config file!
+   bool const Debug = _config->FindB("Debug::GetListOfFilesInDir", false);
+   if (Debug == true)
+   {
+      std::clog << "Accept in " << Dir << " only files with the following " << Ext.size() << " extensions:" << std::endl;
+      if (Ext.empty() == true)
+	 std::clog << "\tNO extension" << std::endl;
+      else
+	 for (std::vector<string>::const_iterator e = Ext.begin();
+	      e != Ext.end(); ++e)
+	    std::clog << '\t' << (e->empty() == true ? "NO" : *e) << " extension" << std::endl;
+   }
+
+   std::vector<string> List;
+
+   if (DirectoryExists(Dir) == false)
+   {
+      _error->Error(_("List of files can't be created as '%s' is not a directory"), Dir.c_str());
+      return List;
+   }
+
+   Configuration::MatchAgainstConfig SilentIgnore("Dir::Ignore-Files-Silently");
+   DIR *D = opendir(Dir.c_str());
+   if (D == 0) 
+   {
+      if (errno == EACCES)
+	 _error->WarningE("opendir", _("Unable to read %s"), Dir.c_str());
+      else
+	 _error->Errno("opendir", _("Unable to read %s"), Dir.c_str());
+      return List;
+   }
+
+   for (struct dirent *Ent = readdir(D); Ent != 0; Ent = readdir(D)) 
+   {
+      // skip "hidden" files
+      if (Ent->d_name[0] == '.')
+	 continue;
+
+      // Make sure it is a file and not something else
+      string const File = flCombine(Dir,Ent->d_name);
+#ifdef _DIRENT_HAVE_D_TYPE
+      if (Ent->d_type != DT_REG)
+#endif
+      {
+	 if (RealFileExists(File) == false)
+	 {
+	    // do not show ignoration warnings for directories
+	    if (
+#ifdef _DIRENT_HAVE_D_TYPE
+		Ent->d_type == DT_DIR ||
+#endif
+		DirectoryExists(File) == true)
+	       continue;
+	    if (SilentIgnore.Match(Ent->d_name) == false)
+	       _error->Notice(_("Ignoring '%s' in directory '%s' as it is not a regular file"), Ent->d_name, Dir.c_str());
+	    continue;
+	 }
+      }
+
+      // check for accepted extension:
+      // no extension given -> periods are bad as hell!
+      // extensions given -> "" extension allows no extension
+      if (Ext.empty() == false)
+      {
+	 string d_ext = flExtension(Ent->d_name);
+	 if (d_ext == Ent->d_name) // no extension
+	 {
+	    if (std::find(Ext.begin(), Ext.end(), "") == Ext.end())
+	    {
+	       if (Debug == true)
+		  std::clog << "Bad file: " << Ent->d_name << " → no extension" << std::endl;
+	       if (SilentIgnore.Match(Ent->d_name) == false)
+		  _error->Notice(_("Ignoring file '%s' in directory '%s' as it has no filename extension"), Ent->d_name, Dir.c_str());
+	       continue;
+	    }
+	 }
+	 else if (std::find(Ext.begin(), Ext.end(), d_ext) == Ext.end())
+	 {
+	    if (Debug == true)
+	       std::clog << "Bad file: " << Ent->d_name << " → bad extension »" << flExtension(Ent->d_name) << "«" << std::endl;
+	    if (SilentIgnore.Match(Ent->d_name) == false)
+	       _error->Notice(_("Ignoring file '%s' in directory '%s' as it has an invalid filename extension"), Ent->d_name, Dir.c_str());
+	    continue;
+	 }
+      }
+
+      // Skip bad filenames ala run-parts
+      const char *C = Ent->d_name;
+      for (; *C != 0; ++C)
+	 if (isalpha(*C) == 0 && isdigit(*C) == 0
+	     && *C != '_' && *C != '-' && *C != ':') {
+	    // no required extension -> dot is a bad character
+	    if (*C == '.' && Ext.empty() == false)
+	       continue;
+	    break;
+	 }
+
+      // we don't reach the end of the name -> bad character included
+      if (*C != 0)
+      {
+	 if (Debug == true)
+	    std::clog << "Bad file: " << Ent->d_name << " → bad character »"
+	       << *C << "« in filename (period allowed: " << (Ext.empty() ? "no" : "yes") << ")" << std::endl;
+	 continue;
+      }
+
+      // skip filenames which end with a period. These are never valid
+      if (*(C - 1) == '.')
+      {
+	 if (Debug == true)
+	    std::clog << "Bad file: " << Ent->d_name << " → Period as last character" << std::endl;
+	 continue;
+      }
+
+      if (Debug == true)
+	 std::clog << "Accept file: " << Ent->d_name << " in " << Dir << std::endl;
+      List.push_back(File);
+   }
+   closedir(D);
+
+   if (SortList == true)
+      std::sort(List.begin(),List.end());
+   return List;
+}
+std::vector<string> GetListOfFilesInDir(string const &Dir, bool SortList)
+{
+   bool const Debug = _config->FindB("Debug::GetListOfFilesInDir", false);
+   if (Debug == true)
+      std::clog << "Accept in " << Dir << " all regular files" << std::endl;
+
+   std::vector<string> List;
+
+   if (DirectoryExists(Dir) == false)
+   {
+      _error->Error(_("List of files can't be created as '%s' is not a directory"), Dir.c_str());
+      return List;
+   }
+
+   DIR *D = opendir(Dir.c_str());
+   if (D == 0)
+   {
+      _error->Errno("opendir",_("Unable to read %s"),Dir.c_str());
+      return List;
+   }
+
+   for (struct dirent *Ent = readdir(D); Ent != 0; Ent = readdir(D)) 
+   {
+      // skip "hidden" files
+      if (Ent->d_name[0] == '.')
+	 continue;
+
+      // Make sure it is a file and not something else
+      string const File = flCombine(Dir,Ent->d_name);
+#ifdef _DIRENT_HAVE_D_TYPE
+      if (Ent->d_type != DT_REG)
+#endif
+      {
+	 if (RealFileExists(File) == false)
+	 {
+	    if (Debug == true)
+	       std::clog << "Bad file: " << Ent->d_name << " → it is not a real file" << std::endl;
+	    continue;
+	 }
+      }
+
+      // Skip bad filenames ala run-parts
+      const char *C = Ent->d_name;
+      for (; *C != 0; ++C)
+	 if (isalpha(*C) == 0 && isdigit(*C) == 0
+	     && *C != '_' && *C != '-' && *C != '.')
+	    break;
+
+      // we don't reach the end of the name -> bad character included
+      if (*C != 0)
+      {
+	 if (Debug == true)
+	    std::clog << "Bad file: " << Ent->d_name << " → bad character »" << *C << "« in filename" << std::endl;
+	 continue;
+      }
+
+      // skip filenames which end with a period. These are never valid
+      if (*(C - 1) == '.')
+      {
+	 if (Debug == true)
+	    std::clog << "Bad file: " << Ent->d_name << " → Period as last character" << std::endl;
+	 continue;
+      }
+
+      if (Debug == true)
+	 std::clog << "Accept file: " << Ent->d_name << " in " << Dir << std::endl;
+      List.push_back(File);
+   }
+   closedir(D);
+
+   if (SortList == true)
+      std::sort(List.begin(),List.end());
+   return List;
+}
+									/*}}}*/
+// SafeGetCWD - This is a safer getcwd that returns a dynamic string	/*{{{*/
+// ---------------------------------------------------------------------
+/* We return / on failure. */
+string SafeGetCWD()
+{
+   // Stash the current dir.
+   char S[300];
+   S[0] = 0;
+   if (getcwd(S,sizeof(S)-2) == 0)
+      return "/";
+   unsigned int Len = strlen(S);
+   S[Len] = '/';
+   S[Len+1] = 0;
+   return S;
+}
+									/*}}}*/
+// GetModificationTime - Get the mtime of the given file or -1 on error /*{{{*/
+// ---------------------------------------------------------------------
+/* We return / on failure. */
+time_t GetModificationTime(string const &Path)
+{
+   struct stat St;
+   if (stat(Path.c_str(), &St) < 0)
+      return -1;
+   return  St.st_mtime;
+}
+									/*}}}*/
+// flNotDir - Strip the directory from the filename			/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+string flNotDir(string File)
+{
+   string::size_type Res = File.rfind('/');
+   if (Res == string::npos)
+      return File;
+   Res++;
+   return string(File,Res,Res - File.length());
+}
+									/*}}}*/
+// flNotFile - Strip the file from the directory name			/*{{{*/
+// ---------------------------------------------------------------------
+/* Result ends in a / */
+string flNotFile(string File)
+{
+   string::size_type Res = File.rfind('/');
+   if (Res == string::npos)
+      return "./";
+   Res++;
+   return string(File,0,Res);
+}
+									/*}}}*/
+// flExtension - Return the extension for the file			/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+string flExtension(string File)
+{
+   string::size_type Res = File.rfind('.');
+   if (Res == string::npos)
+      return File;
+   Res++;
+   return string(File,Res,Res - File.length());
+}
+									/*}}}*/
+// flNoLink - If file is a symlink then deref it			/*{{{*/
+// ---------------------------------------------------------------------
+/* If the name is not a link then the returned path is the input. */
+string flNoLink(string File)
+{
+   struct stat St;
+   if (lstat(File.c_str(),&St) != 0 || S_ISLNK(St.st_mode) == 0)
+      return File;
+   if (stat(File.c_str(),&St) != 0)
+      return File;
+   
+   /* Loop resolving the link. There is no need to limit the number of 
+      loops because the stat call above ensures that the symlink is not 
+      circular */
+   char Buffer[1024];
+   string NFile = File;
+   while (1)
+   {
+      // Read the link
+      ssize_t Res;
+      if ((Res = readlink(NFile.c_str(),Buffer,sizeof(Buffer))) <= 0 || 
+	  (size_t)Res >= sizeof(Buffer))
+	  return File;
+      
+      // Append or replace the previous path
+      Buffer[Res] = 0;
+      if (Buffer[0] == '/')
+	 NFile = Buffer;
+      else
+	 NFile = flNotFile(NFile) + Buffer;
+      
+      // See if we are done
+      if (lstat(NFile.c_str(),&St) != 0)
+	 return File;
+      if (S_ISLNK(St.st_mode) == 0)
+	 return NFile;      
+   }   
+}
+									/*}}}*/
+// flCombine - Combine a file and a directory				/*{{{*/
+// ---------------------------------------------------------------------
+/* If the file is an absolute path then it is just returned, otherwise
+   the directory is pre-pended to it. */
+string flCombine(string Dir,string File)
+{
+   if (File.empty() == true)
+      return string();
+   
+   if (File[0] == '/' || Dir.empty() == true)
+      return File;
+   if (File.length() >= 2 && File[0] == '.' && File[1] == '/')
+      return File;
+   if (Dir[Dir.length()-1] == '/')
+      return Dir + File;
+   return Dir + '/' + File;
+}
+									/*}}}*/
+// flAbsPath - Return the absolute path of the filename			/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+string flAbsPath(string File)
+{
+   char *p = realpath(File.c_str(), NULL);
+   if (p == NULL)
+   {
+      _error->Errno("realpath", "flAbsPath on %s failed", File.c_str());
+      return "";
+   }
+   std::string AbsPath(p);
+   free(p);
+   return AbsPath;
+}
+									/*}}}*/
+std::string flNormalize(std::string file)				/*{{{*/
+{
+   if (file.empty())
+      return file;
+   // do some normalisation by removing // and /./ from the path
+   size_t found = string::npos;
+   while ((found = file.find("/./")) != string::npos)
+      file.replace(found, 3, "/");
+   while ((found = file.find("//")) != string::npos)
+      file.replace(found, 2, "/");
+
+   if (APT::String::Startswith(file, "/dev/null"))
+   {
+      file.erase(strlen("/dev/null"));
+      return file;
+   }
+   return file;
+}
+									/*}}}*/
+// SetCloseExec - Set the close on exec flag				/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+void SetCloseExec(int Fd,bool Close)
+{   
+   if (fcntl(Fd,F_SETFD,(Close == false)?0:FD_CLOEXEC) != 0)
+   {
+      cerr << "FATAL -> Could not set close on exec " << strerror(errno) << endl;
+      exit(100);
+   }
+}
+									/*}}}*/
+// SetNonBlock - Set the nonblocking flag				/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+void SetNonBlock(int Fd,bool Block)
+{   
+   int Flags = fcntl(Fd,F_GETFL) & (~O_NONBLOCK);
+   if (fcntl(Fd,F_SETFL,Flags | ((Block == false)?0:O_NONBLOCK)) != 0)
+   {
+      cerr << "FATAL -> Could not set non-blocking flag " << strerror(errno) << endl;
+      exit(100);
+   }
+}
+									/*}}}*/
+// WaitFd - Wait for a FD to become readable				/*{{{*/
+// ---------------------------------------------------------------------
+/* This waits for a FD to become readable using select. It is useful for
+   applications making use of non-blocking sockets. The timeout is 
+   in seconds. */
+bool WaitFd(int Fd,bool write,unsigned long timeout)
+{
+   fd_set Set;
+   struct timeval tv;
+   FD_ZERO(&Set);
+   FD_SET(Fd,&Set);
+   tv.tv_sec = timeout;
+   tv.tv_usec = 0;
+   if (write == true) 
+   {      
+      int Res;
+      do
+      {
+	 Res = select(Fd+1,0,&Set,0,(timeout != 0?&tv:0));
+      }
+      while (Res < 0 && errno == EINTR);
+      
+      if (Res <= 0)
+	 return false;
+   } 
+   else 
+   {
+      int Res;
+      do
+      {
+	 Res = select(Fd+1,&Set,0,0,(timeout != 0?&tv:0));
+      }
+      while (Res < 0 && errno == EINTR);
+      
+      if (Res <= 0)
+	 return false;
+   }
+   
+   return true;
+}
+									/*}}}*/
+// MergeKeepFdsFromConfiguration - Merge APT::Keep-Fds configuration	/*{{{*/
+// ---------------------------------------------------------------------
+/* This is used to merge the APT::Keep-Fds with the provided KeepFDs
+ * set.
+ */
+void MergeKeepFdsFromConfiguration(std::set<int> &KeepFDs)
+{
+      Configuration::Item const *Opts = _config->Tree("APT::Keep-Fds");
+      if (Opts != 0 && Opts->Child != 0)
+      {
+	 Opts = Opts->Child;
+	 for (; Opts != 0; Opts = Opts->Next)
+	 {
+	    if (Opts->Value.empty() == true)
+	       continue;
+	    int fd = atoi(Opts->Value.c_str());
+	    KeepFDs.insert(fd);
+	 }
+      }
+}
+									/*}}}*/
+// ExecFork - Magical fork that sanitizes the context before execing	/*{{{*/
+// ---------------------------------------------------------------------
+/* This is used if you want to cleanse the environment for the forked 
+   child, it fixes up the important signals and nukes all of the fds,
+   otherwise acts like normal fork. */
+pid_t ExecFork()
+{
+      set<int> KeepFDs;
+      // we need to merge the Keep-Fds as external tools like 
+      // debconf-apt-progress use it
+      MergeKeepFdsFromConfiguration(KeepFDs);
+      return ExecFork(KeepFDs);
+}
+
+pid_t ExecFork(std::set<int> KeepFDs)
+{
+   // Fork off the process
+   pid_t Process = fork();
+   if (Process < 0)
+   {
+      cerr << "FATAL -> Failed to fork." << endl;
+      exit(100);
+   }
+
+   // Spawn the subprocess
+   if (Process == 0)
+   {
+      // Setup the signals
+      signal(SIGPIPE,SIG_DFL);
+      signal(SIGQUIT,SIG_DFL);
+      signal(SIGINT,SIG_DFL);
+      signal(SIGWINCH,SIG_DFL);
+      signal(SIGCONT,SIG_DFL);
+      signal(SIGTSTP,SIG_DFL);
+
+      DIR *dir = opendir("/proc/self/fd");
+      if (dir != NULL)
+      {
+	 struct dirent *ent;
+	 while ((ent = readdir(dir)))
+	 {
+	    int fd = atoi(ent->d_name);
+	    // If fd > 0, it was a fd number and not . or ..
+	    if (fd >= 3 && KeepFDs.find(fd) == KeepFDs.end())
+	       fcntl(fd,F_SETFD,FD_CLOEXEC);
+	 }
+	 closedir(dir);
+      } else {
+	 long ScOpenMax = sysconf(_SC_OPEN_MAX);
+	 // Close all of our FDs - just in case
+	 for (int K = 3; K != ScOpenMax; K++)
+	 {
+	    if(KeepFDs.find(K) == KeepFDs.end())
+	       fcntl(K,F_SETFD,FD_CLOEXEC);
+	 }
+      }
+   }
+   
+   return Process;
+}
+									/*}}}*/
+// ExecWait - Fancy waitpid						/*{{{*/
+// ---------------------------------------------------------------------
+/* Waits for the given sub process. If Reap is set then no errors are 
+   generated. Otherwise a failed subprocess will generate a proper descriptive
+   message */
+bool ExecWait(pid_t Pid,const char *Name,bool Reap)
+{
+   if (Pid <= 1)
+      return true;
+   
+   // Wait and collect the error code
+   int Status;
+   while (waitpid(Pid,&Status,0) != Pid)
+   {
+      if (errno == EINTR)
+	 continue;
+
+      if (Reap == true)
+	 return false;
+      
+      return _error->Error(_("Waited for %s but it wasn't there"),Name);
+   }
+
+   
+   // Check for an error code.
+   if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
+   {
+      if (Reap == true)
+	 return false;
+      if (WIFSIGNALED(Status) != 0)
+      {
+	 if( WTERMSIG(Status) == SIGSEGV)
+	    return _error->Error(_("Sub-process %s received a segmentation fault."),Name);
+	 else 
+	    return _error->Error(_("Sub-process %s received signal %u."),Name, WTERMSIG(Status));
+      }
+
+      if (WIFEXITED(Status) != 0)
+	 return _error->Error(_("Sub-process %s returned an error code (%u)"),Name,WEXITSTATUS(Status));
+      
+      return _error->Error(_("Sub-process %s exited unexpectedly"),Name);
+   }      
+   
+   return true;
+}
+									/*}}}*/
+// StartsWithGPGClearTextSignature - Check if a file is Pgp/GPG clearsigned	/*{{{*/
+bool StartsWithGPGClearTextSignature(string const &FileName)
+{
+   FILE* gpg = fopen(FileName.c_str(), "r");
+   if (gpg == nullptr)
+      return false;
+
+   char * lineptr = nullptr;
+   size_t n = 0;
+   errno = 0;
+   ssize_t const result = getline(&lineptr, &n, gpg);
+   if (errno != 0)
+   {
+      _error->Errno("getline", "Could not read from %s", FileName.c_str());
+      fclose(gpg);
+      free(lineptr);
+      return false;
+   }
+   fclose(gpg);
+
+   _strrstrip(lineptr);
+   static const char* SIGMSG = "-----BEGIN PGP SIGNED MESSAGE-----";
+   if (result == -1 || strcmp(lineptr, SIGMSG) != 0)
+   {
+      free(lineptr);
+      return false;
+   }
+   free(lineptr);
+   return true;
+}
+									/*}}}*/
+// ChangeOwnerAndPermissionOfFile - set file attributes to requested values /*{{{*/
+bool ChangeOwnerAndPermissionOfFile(char const * const requester, char const * const file, char const * const user, char const * const group, mode_t const mode)
+{
+   if (strcmp(file, "/dev/null") == 0)
+      return true;
+   bool Res = true;
+   if (getuid() == 0 && strlen(user) != 0 && strlen(group) != 0) // if we aren't root, we can't chown, so don't try it
+   {
+      // ensure the file is owned by root and has good permissions
+      struct passwd const * const pw = getpwnam(user);
+      struct group const * const gr = getgrnam(group);
+      if (pw != NULL && gr != NULL && lchown(file, pw->pw_uid, gr->gr_gid) != 0)
+	 Res &= _error->WarningE(requester, "chown to %s:%s of file %s failed", user, group, file);
+   }
+   struct stat Buf;
+   if (lstat(file, &Buf) != 0 || S_ISLNK(Buf.st_mode))
+      return Res;
+   if (chmod(file, mode) != 0)
+      Res &= _error->WarningE(requester, "chmod 0%o of file %s failed", mode, file);
+   return Res;
+}
+									/*}}}*/
+
+struct APT_HIDDEN simple_buffer {							/*{{{*/
+   size_t buffersize_max = 0;
+   unsigned long long bufferstart = 0;
+   unsigned long long bufferend = 0;
+   char *buffer = nullptr;
+
+   simple_buffer() {
+      reset(4096);
+   }
+   ~simple_buffer() {
+      delete[] buffer;
+   }
+
+   const char *get() const { return buffer + bufferstart; }
+   char *get() { return buffer + bufferstart; }
+   const char *getend() const { return buffer + bufferend; }
+   char *getend() { return buffer + bufferend; }
+   bool empty() const { return bufferend <= bufferstart; }
+   bool full() const { return bufferend == buffersize_max; }
+   unsigned long long free() const { return buffersize_max - bufferend; }
+   unsigned long long size() const { return bufferend-bufferstart; }
+   void reset(size_t size)
+   {
+      if (size > buffersize_max) {
+	 delete[] buffer;
+	 buffersize_max = size;
+	 buffer = new char[size];
+      }
+      reset();
+   }
+   void reset() { bufferend = bufferstart = 0; }
+   ssize_t read(void *to, unsigned long long requested_size) APT_MUSTCHECK
+   {
+      if (size() < requested_size)
+	 requested_size = size();
+      memcpy(to, buffer + bufferstart, requested_size);
+      bufferstart += requested_size;
+      if (bufferstart == bufferend)
+	 bufferstart = bufferend = 0;
+      return requested_size;
+   }
+   ssize_t write(const void *from, unsigned long long requested_size) APT_MUSTCHECK
+   {
+      if (free() < requested_size)
+	 requested_size = free();
+      memcpy(getend(), from, requested_size);
+      bufferend += requested_size;
+      if (bufferstart == bufferend)
+	 bufferstart = bufferend = 0;
+      return requested_size;
+   }
+};
+									/*}}}*/
+
+class APT_HIDDEN FileFdPrivate {							/*{{{*/
+   friend class BufferedWriteFileFdPrivate;
+protected:
+   FileFd * const filefd;
+   simple_buffer buffer;
+   int compressed_fd;
+   pid_t compressor_pid;
+   bool is_pipe;
+   APT::Configuration::Compressor compressor;
+   unsigned int openmode;
+   unsigned long long seekpos;
+public:
+
+   explicit FileFdPrivate(FileFd * const pfilefd) : filefd(pfilefd),
+      compressed_fd(-1), compressor_pid(-1), is_pipe(false),
+      openmode(0), seekpos(0) {};
+   virtual APT::Configuration::Compressor get_compressor() const
+   {
+      return compressor;
+   }
+   virtual void set_compressor(APT::Configuration::Compressor const &compressor)
+   {
+      this->compressor = compressor;
+   }
+   virtual unsigned int get_openmode() const
+   {
+      return openmode;
+   }
+   virtual void set_openmode(unsigned int openmode)
+   {
+      this->openmode = openmode;
+   }
+   virtual bool get_is_pipe() const
+   {
+      return is_pipe;
+   }
+   virtual void set_is_pipe(bool is_pipe)
+   {
+      this->is_pipe = is_pipe;
+   }
+   virtual unsigned long long get_seekpos() const
+   {
+      return seekpos;
+   }
+   virtual void set_seekpos(unsigned long long seekpos)
+   {
+      this->seekpos = seekpos;
+   }
+
+   virtual bool InternalOpen(int const iFd, unsigned int const Mode) = 0;
+   ssize_t InternalRead(void * To, unsigned long long Size)
+   {
+      // Drain the buffer if needed.
+      if (buffer.empty() == false)
+      {
+	 return buffer.read(To, Size);
+      }
+      return InternalUnbufferedRead(To, Size);
+   }
+   virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) = 0;
+   virtual bool InternalReadError() { return filefd->FileFdErrno("read",_("Read error")); }
+   virtual char * InternalReadLine(char * To, unsigned long long Size)
+   {
+      if (unlikely(Size == 0))
+	 return nullptr;
+      // Read one byte less than buffer size to have space for trailing 0.
+      --Size;
+
+      char * const InitialTo = To;
+
+      while (Size > 0) {
+	 if (buffer.empty() == true)
+	 {
+	    buffer.reset();
+	    unsigned long long actualread = 0;
+	    if (filefd->Read(buffer.getend(), buffer.free(), &actualread) == false)
+	       return nullptr;
+	    buffer.bufferend = actualread;
+	    if (buffer.size() == 0)
+	    {
+	       if (To == InitialTo)
+		  return nullptr;
+	       break;
+	    }
+	    filefd->Flags &= ~FileFd::HitEof;
+	 }
+
+	 unsigned long long const OutputSize = std::min(Size, buffer.size());
+	 char const * const newline = static_cast<char const *>(memchr(buffer.get(), '\n', OutputSize));
+	 // Read until end of line or up to Size bytes from the buffer.
+	 unsigned long long actualread = buffer.read(To,
+						     (newline != nullptr)
+						     ? (newline - buffer.get()) + 1
+						     : OutputSize);
+	 To += actualread;
+	 Size -= actualread;
+	 if (newline != nullptr)
+	    break;
+      }
+      *To = '\0';
+      return InitialTo;
+   }
+   virtual bool InternalFlush()
+   {
+      return true;
+   }
+   virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) = 0;
+   virtual bool InternalWriteError() { return filefd->FileFdErrno("write",_("Write error")); }
+   virtual bool InternalSeek(unsigned long long const To)
+   {
+      // Our poor man seeking is costly, so try to avoid it
+      unsigned long long const iseekpos = filefd->Tell();
+      if (iseekpos == To)
+	 return true;
+      else if (iseekpos < To)
+	 return filefd->Skip(To - iseekpos);
+
+      if ((openmode & FileFd::ReadOnly) != FileFd::ReadOnly)
+	 return filefd->FileFdError("Reopen is only implemented for read-only files!");
+      InternalClose(filefd->FileName);
+      if (filefd->iFd != -1)
+	 close(filefd->iFd);
+      filefd->iFd = -1;
+      if (filefd->TemporaryFileName.empty() == false)
+	 filefd->iFd = open(filefd->TemporaryFileName.c_str(), O_RDONLY);
+      else if (filefd->FileName.empty() == false)
+	 filefd->iFd = open(filefd->FileName.c_str(), O_RDONLY);
+      else
+      {
+	 if (compressed_fd > 0)
+	    if (lseek(compressed_fd, 0, SEEK_SET) != 0)
+	       filefd->iFd = compressed_fd;
+	 if (filefd->iFd < 0)
+	    return filefd->FileFdError("Reopen is not implemented for pipes opened with FileFd::OpenDescriptor()!");
+      }
+
+      if (filefd->OpenInternDescriptor(openmode, compressor) == false)
+	 return filefd->FileFdError("Seek on file %s because it couldn't be reopened", filefd->FileName.c_str());
+
+      buffer.reset();
+      set_seekpos(0);
+      if (To != 0)
+	 return filefd->Skip(To);
+
+      seekpos = To;
+      return true;
+   }
+   virtual bool InternalSkip(unsigned long long Over)
+   {
+      unsigned long long constexpr buffersize = 1024;
+      char buffer[buffersize];
+      while (Over != 0)
+      {
+	 unsigned long long toread = std::min(buffersize, Over);
+	 if (filefd->Read(buffer, toread) == false)
+	    return filefd->FileFdError("Unable to seek ahead %llu",Over);
+	 Over -= toread;
+      }
+      return true;
+   }
+   virtual bool InternalTruncate(unsigned long long const)
+   {
+      return filefd->FileFdError("Truncating compressed files is not implemented (%s)", filefd->FileName.c_str());
+   }
+   virtual unsigned long long InternalTell()
+   {
+      // In theory, we could just return seekpos here always instead of
+      // seeking around, but not all users of FileFd use always Seek() and co
+      // so d->seekpos isn't always true and we can just use it as a hint if
+      // we have nothing else, but not always as an authority…
+      return seekpos - buffer.size();
+   }
+   virtual unsigned long long InternalSize()
+   {
+      unsigned long long size = 0;
+      unsigned long long const oldSeek = filefd->Tell();
+      unsigned long long constexpr ignoresize = 1024;
+      char ignore[ignoresize];
+      unsigned long long read = 0;
+      do {
+	 if (filefd->Read(ignore, ignoresize, &read) == false)
+	 {
+	    filefd->Seek(oldSeek);
+	    return 0;
+	 }
+      } while(read != 0);
+      size = filefd->Tell();
+      filefd->Seek(oldSeek);
+      return size;
+   }
+   virtual bool InternalClose(std::string const &FileName) = 0;
+   virtual bool InternalStream() const { return false; }
+   virtual bool InternalAlwaysAutoClose() const { return true; }
+
+   virtual ~FileFdPrivate() {}
+};
+									/*}}}*/
+class APT_HIDDEN BufferedWriteFileFdPrivate : public FileFdPrivate {	/*{{{*/
+protected:
+   FileFdPrivate *wrapped;
+   simple_buffer writebuffer;
+
+public:
+
+   explicit BufferedWriteFileFdPrivate(FileFdPrivate *Priv) :
+      FileFdPrivate(Priv->filefd), wrapped(Priv) {};
+
+   virtual APT::Configuration::Compressor get_compressor() const APT_OVERRIDE
+   {
+      return wrapped->get_compressor();
+   }
+   virtual void set_compressor(APT::Configuration::Compressor const &compressor)  APT_OVERRIDE
+   {
+      return wrapped->set_compressor(compressor);
+   }
+   virtual unsigned int get_openmode() const  APT_OVERRIDE
+   {
+      return wrapped->get_openmode();
+   }
+   virtual void set_openmode(unsigned int openmode)  APT_OVERRIDE
+   {
+      return wrapped->set_openmode(openmode);
+   }
+   virtual bool get_is_pipe() const  APT_OVERRIDE
+   {
+      return wrapped->get_is_pipe();
+   }
+   virtual void set_is_pipe(bool is_pipe) APT_OVERRIDE
+   {
+      FileFdPrivate::set_is_pipe(is_pipe);
+      wrapped->set_is_pipe(is_pipe);
+   }
+   virtual unsigned long long get_seekpos() const APT_OVERRIDE
+   {
+      return wrapped->get_seekpos();
+   }
+   virtual void set_seekpos(unsigned long long seekpos) APT_OVERRIDE
+   {
+      return wrapped->set_seekpos(seekpos);
+   }
+   virtual bool InternalOpen(int const iFd, unsigned int const Mode) APT_OVERRIDE
+   {
+      if (InternalFlush() == false)
+	 return false;
+      return wrapped->InternalOpen(iFd, Mode);
+   }
+   virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE
+   {
+      if (InternalFlush() == false)
+	 return -1;
+      return wrapped->InternalUnbufferedRead(To, Size);
+
+   }
+   virtual bool InternalReadError() APT_OVERRIDE
+   {
+      return wrapped->InternalReadError();
+   }
+   virtual char * InternalReadLine(char * To, unsigned long long Size) APT_OVERRIDE
+   {
+      if (InternalFlush() == false)
+	 return nullptr;
+      return wrapped->InternalReadLine(To, Size);
+   }
+   virtual bool InternalFlush() APT_OVERRIDE
+   {
+      while (writebuffer.empty() == false) {
+	 auto written = wrapped->InternalWrite(writebuffer.get(),
+					       writebuffer.size());
+	 // Ignore interrupted syscalls
+	 if (written < 0 && errno == EINTR)
+	    continue;
+	 if (written < 0)
+	    return wrapped->InternalWriteError();
+
+	 writebuffer.bufferstart += written;
+      }
+      writebuffer.reset();
+      return wrapped->InternalFlush();
+   }
+   virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE
+   {
+      // Optimisation: If the buffer is empty and we have more to write than
+      // would fit in the buffer (or equal number of bytes), write directly.
+      if (writebuffer.empty() == true && Size >= writebuffer.free())
+	 return wrapped->InternalWrite(From, Size);
+
+      // Write as much into the buffer as possible and then flush if needed
+      auto written = writebuffer.write(From, Size);
+
+      if (writebuffer.full() && InternalFlush() == false)
+	 return -1;
+
+      return written;
+   }
+   virtual bool InternalWriteError() APT_OVERRIDE
+   {
+      return wrapped->InternalWriteError();
+   }
+   virtual bool InternalSeek(unsigned long long const To) APT_OVERRIDE
+   {
+      if (InternalFlush() == false)
+	 return false;
+      return wrapped->InternalSeek(To);
+   }
+   virtual bool InternalSkip(unsigned long long Over) APT_OVERRIDE
+   {
+      if (InternalFlush() == false)
+	 return false;
+      return wrapped->InternalSkip(Over);
+   }
+   virtual bool InternalTruncate(unsigned long long const Size) APT_OVERRIDE
+   {
+      if (InternalFlush() == false)
+	 return false;
+      return wrapped->InternalTruncate(Size);
+   }
+   virtual unsigned long long InternalTell() APT_OVERRIDE
+   {
+      if (InternalFlush() == false)
+	 return -1;
+      return wrapped->InternalTell();
+   }
+   virtual unsigned long long InternalSize() APT_OVERRIDE
+   {
+      if (InternalFlush() == false)
+	 return -1;
+      return wrapped->InternalSize();
+   }
+   virtual bool InternalClose(std::string const &FileName) APT_OVERRIDE
+   {
+      return wrapped->InternalClose(FileName);
+   }
+   virtual bool InternalAlwaysAutoClose() const APT_OVERRIDE
+   {
+      return wrapped->InternalAlwaysAutoClose();
+   }
+   virtual ~BufferedWriteFileFdPrivate()
+   {
+      delete wrapped;
+   }
+};
+									/*}}}*/
+class APT_HIDDEN GzipFileFdPrivate: public FileFdPrivate {				/*{{{*/
+#ifdef HAVE_ZLIB
+public:
+   gzFile gz;
+   virtual bool InternalOpen(int const iFd, unsigned int const Mode) APT_OVERRIDE
+   {
+      if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite)
+	 gz = gzdopen(iFd, "r+");
+      else if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly)
+	 gz = gzdopen(iFd, "w");
+      else
+	 gz = gzdopen(iFd, "r");
+      filefd->Flags |= FileFd::Compressed;
+      return gz != nullptr;
+   }
+   virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE
+   {
+      return gzread(gz, To, Size);
+   }
+   virtual bool InternalReadError() APT_OVERRIDE
+   {
+      int err;
+      char const * const errmsg = gzerror(gz, &err);
+      if (err != Z_ERRNO)
+	 return filefd->FileFdError("gzread: %s (%d: %s)", _("Read error"), err, errmsg);
+      return FileFdPrivate::InternalReadError();
+   }
+   virtual char * InternalReadLine(char * To, unsigned long long Size) APT_OVERRIDE
+   {
+      return gzgets(gz, To, Size);
+   }
+   virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE
+   {
+      return gzwrite(gz,From,Size);
+   }
+   virtual bool InternalWriteError() APT_OVERRIDE
+   {
+      int err;
+      char const * const errmsg = gzerror(gz, &err);
+      if (err != Z_ERRNO)
+	 return filefd->FileFdError("gzwrite: %s (%d: %s)", _("Write error"), err, errmsg);
+      return FileFdPrivate::InternalWriteError();
+   }
+   virtual bool InternalSeek(unsigned long long const To) APT_OVERRIDE
+   {
+      off_t const res = gzseek(gz, To, SEEK_SET);
+      if (res != (off_t)To)
+	 return filefd->FileFdError("Unable to seek to %llu", To);
+      seekpos = To;
+      buffer.reset();
+      return true;
+   }
+   virtual bool InternalSkip(unsigned long long Over) APT_OVERRIDE
+   {
+      if (Over >= buffer.size())
+      {
+	 Over -= buffer.size();
+	 buffer.reset();
+      }
+      else
+      {
+	 buffer.bufferstart += Over;
+	 return true;
+      }
+      if (Over == 0)
+	 return true;
+      off_t const res = gzseek(gz, Over, SEEK_CUR);
+      if (res < 0)
+	 return filefd->FileFdError("Unable to seek ahead %llu",Over);
+      seekpos = res;
+      return true;
+   }
+   virtual unsigned long long InternalTell() APT_OVERRIDE
+   {
+      return gztell(gz) - buffer.size();
+   }
+   virtual unsigned long long InternalSize() APT_OVERRIDE
+   {
+      unsigned long long filesize = FileFdPrivate::InternalSize();
+      // only check gzsize if we are actually a gzip file, just checking for
+      // "gz" is not sufficient as uncompressed files could be opened with
+      // gzopen in "direct" mode as well
+      if (filesize == 0 || gzdirect(gz))
+	 return filesize;
+
+      off_t const oldPos = lseek(filefd->iFd, 0, SEEK_CUR);
+      /* unfortunately zlib.h doesn't provide a gzsize(), so we have to do
+       * this ourselves; the original (uncompressed) file size is the last 32
+       * bits of the file */
+      // FIXME: Size for gz-files is limited by 32bit… no largefile support
+      if (lseek(filefd->iFd, -4, SEEK_END) < 0)
+      {
+	 filefd->FileFdErrno("lseek","Unable to seek to end of gzipped file");
+	 return 0;
+      }
+      uint32_t size = 0;
+      if (read(filefd->iFd, &size, 4) != 4)
+      {
+	 filefd->FileFdErrno("read","Unable to read original size of gzipped file");
+	 return 0;
+      }
+      size = le32toh(size);
+
+      if (lseek(filefd->iFd, oldPos, SEEK_SET) < 0)
+      {
+	 filefd->FileFdErrno("lseek","Unable to seek in gzipped file");
+	 return 0;
+      }
+      return size;
+   }
+   virtual bool InternalClose(std::string const &FileName) APT_OVERRIDE
+   {
+      if (gz == nullptr)
+	 return true;
+      int const e = gzclose(gz);
+      gz = nullptr;
+      // gzdclose() on empty files always fails with "buffer error" here, ignore that
+      if (e != 0 && e != Z_BUF_ERROR)
+	 return _error->Errno("close",_("Problem closing the gzip file %s"), FileName.c_str());
+      return true;
+   }
+
+   explicit GzipFileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd), gz(nullptr) {}
+   virtual ~GzipFileFdPrivate() { InternalClose(""); }
+#endif
+};
+									/*}}}*/
+class APT_HIDDEN Bz2FileFdPrivate: public FileFdPrivate {				/*{{{*/
+#ifdef HAVE_BZ2
+   BZFILE* bz2;
+public:
+   virtual bool InternalOpen(int const iFd, unsigned int const Mode) APT_OVERRIDE
+   {
+      if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite)
+	 bz2 = BZ2_bzdopen(iFd, "r+");
+      else if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly)
+	 bz2 = BZ2_bzdopen(iFd, "w");
+      else
+	 bz2 = BZ2_bzdopen(iFd, "r");
+      filefd->Flags |= FileFd::Compressed;
+      return bz2 != nullptr;
+   }
+   virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE
+   {
+      return BZ2_bzread(bz2, To, Size);
+   }
+   virtual bool InternalReadError() APT_OVERRIDE
+   {
+      int err;
+      char const * const errmsg = BZ2_bzerror(bz2, &err);
+      if (err != BZ_IO_ERROR)
+	 return filefd->FileFdError("BZ2_bzread: %s %s (%d: %s)", filefd->FileName.c_str(), _("Read error"), err, errmsg);
+      return FileFdPrivate::InternalReadError();
+   }
+   virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE
+   {
+      return BZ2_bzwrite(bz2, (void*)From, Size);
+   }
+   virtual bool InternalWriteError() APT_OVERRIDE
+   {
+      int err;
+      char const * const errmsg = BZ2_bzerror(bz2, &err);
+      if (err != BZ_IO_ERROR)
+	 return filefd->FileFdError("BZ2_bzwrite: %s %s (%d: %s)", filefd->FileName.c_str(), _("Write error"), err, errmsg);
+      return FileFdPrivate::InternalWriteError();
+   }
+   virtual bool InternalStream() const APT_OVERRIDE { return true; }
+   virtual bool InternalClose(std::string const &) APT_OVERRIDE
+   {
+      if (bz2 == nullptr)
+	 return true;
+      BZ2_bzclose(bz2);
+      bz2 = nullptr;
+      return true;
+   }
+
+   explicit Bz2FileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd), bz2(nullptr) {}
+   virtual ~Bz2FileFdPrivate() { InternalClose(""); }
+#endif
+};
+									/*}}}*/
+class APT_HIDDEN Lz4FileFdPrivate: public FileFdPrivate {				/*{{{*/
+   static constexpr unsigned long long LZ4_HEADER_SIZE = 19;
+   static constexpr unsigned long long LZ4_FOOTER_SIZE = 4;
+#ifdef HAVE_LZ4
+   LZ4F_decompressionContext_t dctx;
+   LZ4F_compressionContext_t cctx;
+   LZ4F_errorCode_t res;
+   FileFd backend;
+   simple_buffer lz4_buffer;
+   // Count of bytes that the decompressor expects to read next, or buffer size.
+   size_t next_to_load = APT_BUFFER_SIZE;
+public:
+   virtual bool InternalOpen(int const iFd, unsigned int const Mode) APT_OVERRIDE
+   {
+      if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite)
+	 return _error->Error("lz4 only supports write or read mode");
+
+      if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly) {
+	 res = LZ4F_createCompressionContext(&cctx, LZ4F_VERSION);
+	 lz4_buffer.reset(LZ4F_compressBound(APT_BUFFER_SIZE, nullptr)
+			  + LZ4_HEADER_SIZE + LZ4_FOOTER_SIZE);
+      } else {
+	 res = LZ4F_createDecompressionContext(&dctx, LZ4F_VERSION);
+	 lz4_buffer.reset(APT_BUFFER_SIZE);
+      }
+
+      filefd->Flags |= FileFd::Compressed;
+
+      if (LZ4F_isError(res))
+	 return false;
+
+      unsigned int flags = (Mode & (FileFd::WriteOnly|FileFd::ReadOnly));
+      if (backend.OpenDescriptor(iFd, flags, FileFd::None, true) == false)
+	 return false;
+
+      // Write the file header
+      if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly)
+      {
+	 res = LZ4F_compressBegin(cctx, lz4_buffer.buffer, lz4_buffer.buffersize_max, nullptr);
+	 if (LZ4F_isError(res) || backend.Write(lz4_buffer.buffer, res) == false)
+	    return false;
+      }
+
+      return true;
+   }
+   virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE
+   {
+      /* Keep reading as long as the compressor still wants to read */
+      while (next_to_load) {
+	 // Fill compressed buffer;
+	 if (lz4_buffer.empty()) {
+	    unsigned long long read;
+	    /* Reset - if LZ4 decompressor wants to read more, allocate more */
+	    lz4_buffer.reset(next_to_load);
+	    if (backend.Read(lz4_buffer.getend(), lz4_buffer.free(), &read) == false)
+	       return -1;
+	    lz4_buffer.bufferend += read;
+
+	    /* Expected EOF */
+	    if (read == 0) {
+	       res = -1;
+	       return filefd->FileFdError("LZ4F: %s %s",
+					  filefd->FileName.c_str(),
+					  _("Unexpected end of file")), -1;
+	    }
+	 }
+	 // Drain compressed buffer as far as possible.
+	 size_t in = lz4_buffer.size();
+	 size_t out = Size;
+
+	 res = LZ4F_decompress(dctx, To, &out, lz4_buffer.get(), &in, nullptr);
+	 if (LZ4F_isError(res))
+	       return -1;
+
+	 next_to_load = res;
+	 lz4_buffer.bufferstart += in;
+
+	 if (out != 0)
+	    return out;
+      }
+
+      return 0;
+   }
+   virtual bool InternalReadError() APT_OVERRIDE
+   {
+      char const * const errmsg = LZ4F_getErrorName(res);
+
+      return filefd->FileFdError("LZ4F: %s %s (%zu: %s)", filefd->FileName.c_str(), _("Read error"), res, errmsg);
+   }
+   virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE
+   {
+      unsigned long long const towrite = std::min(APT_BUFFER_SIZE, Size);
+
+      res = LZ4F_compressUpdate(cctx,
+				lz4_buffer.buffer, lz4_buffer.buffersize_max,
+				From, towrite, nullptr);
+
+      if (LZ4F_isError(res) || backend.Write(lz4_buffer.buffer, res) == false)
+	 return -1;
+
+      return towrite;
+   }
+   virtual bool InternalWriteError() APT_OVERRIDE
+   {
+      char const * const errmsg = LZ4F_getErrorName(res);
+
+      return filefd->FileFdError("LZ4F: %s %s (%zu: %s)", filefd->FileName.c_str(), _("Write error"), res, errmsg);
+   }
+   virtual bool InternalStream() const APT_OVERRIDE { return true; }
+
+   virtual bool InternalFlush() APT_OVERRIDE
+   {
+      return backend.Flush();
+   }
+
+   virtual bool InternalClose(std::string const &) APT_OVERRIDE
+   {
+      /* Reset variables */
+      res = 0;
+      next_to_load = APT_BUFFER_SIZE;
+
+      if (cctx != nullptr)
+      {
+	 if (filefd->Failed() == false)
+	 {
+	    res = LZ4F_compressEnd(cctx, lz4_buffer.buffer, lz4_buffer.buffersize_max, nullptr);
+	    if (LZ4F_isError(res) || backend.Write(lz4_buffer.buffer, res) == false)
+	       return false;
+	    if (!backend.Flush())
+	       return false;
+	 }
+	 if (!backend.Close())
+	    return false;
+
+	 res = LZ4F_freeCompressionContext(cctx);
+	 cctx = nullptr;
+      }
+
+      if (dctx != nullptr)
+      {
+	 res = LZ4F_freeDecompressionContext(dctx);
+	 dctx = nullptr;
+      }
+      if (backend.IsOpen())
+      {
+	 backend.Close();
+	 filefd->iFd = -1;
+      }
+
+      return LZ4F_isError(res) == false;
+   }
+
+   explicit Lz4FileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd), dctx(nullptr), cctx(nullptr) {}
+   virtual ~Lz4FileFdPrivate() {
+      InternalClose("");
+   }
+#endif
+};
+									/*}}}*/
+
+class APT_HIDDEN ZstdFileFdPrivate : public FileFdPrivate
+{ /*{{{*/
+#ifdef HAVE_ZSTD
+   ZSTD_DStream *dctx;
+   ZSTD_CStream *cctx;
+   size_t res;
+   FileFd backend;
+   simple_buffer zstd_buffer;
+   // Count of bytes that the decompressor expects to read next, or buffer size.
+   size_t next_to_load = APT_BUFFER_SIZE;
+
+   public:
+   virtual bool InternalOpen(int const iFd, unsigned int const Mode) APT_OVERRIDE
+   {
+      if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite)
+	 return _error->Error("zstd only supports write or read mode");
+
+      if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly)
+      {
+	 cctx = ZSTD_createCStream();
+	 res = ZSTD_initCStream(cctx, findLevel(compressor.CompressArgs));
+	 zstd_buffer.reset(APT_BUFFER_SIZE);
+      }
+      else
+      {
+	 dctx = ZSTD_createDStream();
+	 res = ZSTD_initDStream(dctx);
+	 zstd_buffer.reset(APT_BUFFER_SIZE);
+      }
+
+      filefd->Flags |= FileFd::Compressed;
+
+      if (ZSTD_isError(res))
+	 return false;
+
+      unsigned int flags = (Mode & (FileFd::WriteOnly | FileFd::ReadOnly));
+      if (backend.OpenDescriptor(iFd, flags, FileFd::None, true) == false)
+	 return false;
+
+      return true;
+   }
+   virtual ssize_t InternalUnbufferedRead(void *const To, unsigned long long const Size) APT_OVERRIDE
+   {
+      /* Keep reading as long as the compressor still wants to read */
+      while (true)
+      {
+	 // Fill compressed buffer;
+	 if (zstd_buffer.empty())
+	 {
+	    unsigned long long read;
+	    /* Reset - if LZ4 decompressor wants to read more, allocate more */
+	    zstd_buffer.reset(next_to_load);
+	    if (backend.Read(zstd_buffer.getend(), zstd_buffer.free(), &read) == false)
+	       return -1;
+	    zstd_buffer.bufferend += read;
+
+	    if (read == 0)
+	    {
+	       /* Expected EOF */
+	       if (next_to_load == 0)
+		  return 0;
+
+	       res = -1;
+	       return filefd->FileFdError("ZSTD: %s %s",
+					  filefd->FileName.c_str(),
+					  _("Unexpected end of file")),
+		      -1;
+	    }
+	 }
+	 // Drain compressed buffer as far as possible.
+	 ZSTD_inBuffer in = {
+	    .src = zstd_buffer.get(),
+	    .size = zstd_buffer.size(),
+	    .pos = 0,
+	 };
+	 ZSTD_outBuffer out = {
+	    .dst = To,
+	    .size = Size,
+	    .pos = 0,
+	 };
+
+	 next_to_load = res = ZSTD_decompressStream(dctx, &out, &in);
+
+	 if (res == 0)
+	 {
+	    res = ZSTD_initDStream(dctx);
+	 }
+
+	 if (ZSTD_isError(res))
+	    return -1;
+
+	 zstd_buffer.bufferstart += in.pos;
+
+	 if (out.pos != 0)
+	    return out.pos;
+      }
+
+      return 0;
+   }
+   virtual bool InternalReadError() APT_OVERRIDE
+   {
+      char const *const errmsg = ZSTD_getErrorName(res);
+
+      return filefd->FileFdError("ZSTD: %s %s (%zu: %s)", filefd->FileName.c_str(), _("Read error"), res, errmsg);
+   }
+   virtual ssize_t InternalWrite(void const *const From, unsigned long long const Size) APT_OVERRIDE
+   {
+      // Drain compressed buffer as far as possible.
+      ZSTD_outBuffer out = {
+	 .dst = zstd_buffer.buffer,
+	 .size = zstd_buffer.buffersize_max,
+	 .pos = 0,
+      };
+      ZSTD_inBuffer in = {
+	 .src = From,
+	 .size = Size,
+	 .pos = 0,
+      };
+
+      res = ZSTD_compressStream(cctx, &out, &in);
+
+      if (ZSTD_isError(res) || backend.Write(zstd_buffer.buffer, out.pos) == false)
+	 return -1;
+
+      return in.pos;
+   }
+
+   virtual bool InternalWriteError() APT_OVERRIDE
+   {
+      char const *const errmsg = ZSTD_getErrorName(res);
+
+      return filefd->FileFdError("ZSTD: %s %s (%zu: %s)", filefd->FileName.c_str(), _("Write error"), res, errmsg);
+   }
+   virtual bool InternalStream() const APT_OVERRIDE { return true; }
+
+   virtual bool InternalFlush() APT_OVERRIDE
+   {
+      return backend.Flush();
+   }
+
+   virtual bool InternalClose(std::string const &) APT_OVERRIDE
+   {
+      /* Reset variables */
+      res = 0;
+      next_to_load = APT_BUFFER_SIZE;
+
+      if (cctx != nullptr)
+      {
+	 if (filefd->Failed() == false)
+	 {
+	    do
+	    {
+	       ZSTD_outBuffer out = {
+		  .dst = zstd_buffer.buffer,
+		  .size = zstd_buffer.buffersize_max,
+		  .pos = 0,
+	       };
+	       res = ZSTD_endStream(cctx, &out);
+	       if (ZSTD_isError(res) || backend.Write(zstd_buffer.buffer, out.pos) == false)
+		  return false;
+	    } while (res > 0);
+
+	    if (!backend.Flush())
+	       return false;
+	 }
+	 if (!backend.Close())
+	    return false;
+
+	 res = ZSTD_freeCStream(cctx);
+	 cctx = nullptr;
+      }
+
+      if (dctx != nullptr)
+      {
+	 res = ZSTD_freeDStream(dctx);
+	 dctx = nullptr;
+      }
+      if (backend.IsOpen())
+      {
+	 backend.Close();
+	 filefd->iFd = -1;
+      }
+
+      return ZSTD_isError(res) == false;
+   }
+
+   static uint32_t findLevel(std::vector<std::string> const &Args)
+   {
+      for (auto a = Args.rbegin(); a != Args.rend(); ++a)
+      {
+	 if (a->size() >= 2 && (*a)[0] == '-' && (*a)[1] != '-')
+	 {
+	    auto const level = a->substr(1);
+	    auto const notANumber = level.find_first_not_of("0123456789");
+	    if (notANumber != std::string::npos)
+	       continue;
+
+	    return (uint32_t)stoi(level);
+	 }
+      }
+      return 19;
+   }
+
+   explicit ZstdFileFdPrivate(FileFd *const filefd) : FileFdPrivate(filefd), dctx(nullptr), cctx(nullptr) {}
+   virtual ~ZstdFileFdPrivate()
+   {
+      InternalClose("");
+   }
+#endif
+};
+									/*}}}*/
+class APT_HIDDEN LzmaFileFdPrivate: public FileFdPrivate {				/*{{{*/
+#ifdef HAVE_LZMA
+   struct LZMAFILE {
+      FILE* file;
+      FileFd * const filefd;
+      uint8_t buffer[4096];
+      lzma_stream stream;
+      lzma_ret err;
+      bool eof;
+      bool compressing;
+
+      LZMAFILE(FileFd * const fd) : file(nullptr), filefd(fd), eof(false), compressing(false) { buffer[0] = '\0'; }
+      ~LZMAFILE()
+      {
+	 if (compressing == true && filefd->Failed() == false)
+	 {
+	    size_t constexpr buffersize = sizeof(buffer)/sizeof(buffer[0]);
+	    while(true)
+	    {
+	       stream.avail_out = buffersize;
+	       stream.next_out = buffer;
+	       err = lzma_code(&stream, LZMA_FINISH);
+	       if (err != LZMA_OK && err != LZMA_STREAM_END)
+	       {
+		  _error->Error("~LZMAFILE: Compress finalisation failed");
+		  break;
+	       }
+	       size_t const n =  buffersize - stream.avail_out;
+	       if (n && fwrite(buffer, 1, n, file) != n)
+	       {
+		  _error->Errno("~LZMAFILE",_("Write error"));
+		  break;
+	       }
+	       if (err == LZMA_STREAM_END)
+		  break;
+	    }
+	 }
+	 lzma_end(&stream);
+	 fclose(file);
+      }
+   };
+   LZMAFILE* lzma;
+   static uint32_t findXZlevel(std::vector<std::string> const &Args)
+   {
+      for (auto a = Args.rbegin(); a != Args.rend(); ++a)
+	 if (a->empty() == false && (*a)[0] == '-' && (*a)[1] != '-')
+	 {
+	    auto const number = a->find_last_of("0123456789");
+	    if (number == std::string::npos)
+	       continue;
+	    auto const extreme = a->find("e", number);
+	    uint32_t level = (extreme != std::string::npos) ? LZMA_PRESET_EXTREME : 0;
+	    switch ((*a)[number])
+	    {
+	       case '0': return level | 0;
+	       case '1': return level | 1;
+	       case '2': return level | 2;
+	       case '3': return level | 3;
+	       case '4': return level | 4;
+	       case '5': return level | 5;
+	       case '6': return level | 6;
+	       case '7': return level | 7;
+	       case '8': return level | 8;
+	       case '9': return level | 9;
+	    }
+	 }
+      return 6;
+   }
+public:
+   virtual bool InternalOpen(int const iFd, unsigned int const Mode) APT_OVERRIDE
+   {
+      if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite)
+	 return filefd->FileFdError("ReadWrite mode is not supported for lzma/xz files %s", filefd->FileName.c_str());
+
+      if (lzma == nullptr)
+	 lzma = new LzmaFileFdPrivate::LZMAFILE(filefd);
+      if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly)
+	 lzma->file = fdopen(iFd, "w");
+      else
+	 lzma->file = fdopen(iFd, "r");
+      filefd->Flags |= FileFd::Compressed;
+      if (lzma->file == nullptr)
+	 return false;
+
+      lzma_stream tmp_stream = LZMA_STREAM_INIT;
+      lzma->stream = tmp_stream;
+
+      if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly)
+      {
+	 uint32_t const xzlevel = findXZlevel(compressor.CompressArgs);
+	 if (compressor.Name == "xz")
+	 {
+	    if (lzma_easy_encoder(&lzma->stream, xzlevel, LZMA_CHECK_CRC64) != LZMA_OK)
+	       return false;
+	 }
+	 else
+	 {
+	    lzma_options_lzma options;
+	    lzma_lzma_preset(&options, xzlevel);
+	    if (lzma_alone_encoder(&lzma->stream, &options) != LZMA_OK)
+	       return false;
+	 }
+	 lzma->compressing = true;
+      }
+      else
+      {
+	 uint64_t const memlimit = UINT64_MAX;
+	 if (compressor.Name == "xz")
+	 {
+	    if (lzma_auto_decoder(&lzma->stream, memlimit, 0) != LZMA_OK)
+	       return false;
+	 }
+	 else
+	 {
+	    if (lzma_alone_decoder(&lzma->stream, memlimit) != LZMA_OK)
+	       return false;
+	 }
+	 lzma->compressing = false;
+      }
+      return true;
+   }
+   virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE
+   {
+      ssize_t Res;
+      if (lzma->eof == true)
+	 return 0;
+
+      lzma->stream.next_out = (uint8_t *) To;
+      lzma->stream.avail_out = Size;
+      if (lzma->stream.avail_in == 0)
+      {
+	 lzma->stream.next_in = lzma->buffer;
+	 lzma->stream.avail_in = fread(lzma->buffer, 1, sizeof(lzma->buffer)/sizeof(lzma->buffer[0]), lzma->file);
+      }
+      lzma->err = lzma_code(&lzma->stream, LZMA_RUN);
+      if (lzma->err == LZMA_STREAM_END)
+      {
+	 lzma->eof = true;
+	 Res = Size - lzma->stream.avail_out;
+      }
+      else if (lzma->err != LZMA_OK)
+      {
+	 Res = -1;
+	 errno = 0;
+      }
+      else
+      {
+	 Res = Size - lzma->stream.avail_out;
+	 if (Res == 0)
+	 {
+	    // lzma run was okay, but produced no output…
+	    Res = -1;
+	    errno = EINTR;
+	 }
+      }
+      return Res;
+   }
+   virtual bool InternalReadError() APT_OVERRIDE
+   {
+      return filefd->FileFdError("lzma_read: %s (%d)", _("Read error"), lzma->err);
+   }
+   virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE
+   {
+      ssize_t Res;
+      lzma->stream.next_in = (uint8_t *)From;
+      lzma->stream.avail_in = Size;
+      lzma->stream.next_out = lzma->buffer;
+      lzma->stream.avail_out = sizeof(lzma->buffer)/sizeof(lzma->buffer[0]);
+      lzma->err = lzma_code(&lzma->stream, LZMA_RUN);
+      if (lzma->err != LZMA_OK)
+	 return -1;
+      size_t const n = sizeof(lzma->buffer)/sizeof(lzma->buffer[0]) - lzma->stream.avail_out;
+      size_t const m = (n == 0) ? 0 : fwrite(lzma->buffer, 1, n, lzma->file);
+      if (m != n)
+      {
+	 Res = -1;
+	 errno = 0;
+      }
+      else
+      {
+	 Res = Size - lzma->stream.avail_in;
+	 if (Res == 0)
+	 {
+	    // lzma run was okay, but produced no output…
+	    Res = -1;
+	    errno = EINTR;
+	 }
+      }
+      return Res;
+   }
+   virtual bool InternalWriteError() APT_OVERRIDE
+   {
+      return filefd->FileFdError("lzma_write: %s (%d)", _("Write error"), lzma->err);
+   }
+   virtual bool InternalStream() const APT_OVERRIDE { return true; }
+   virtual bool InternalClose(std::string const &) APT_OVERRIDE
+   {
+      delete lzma;
+      lzma = nullptr;
+      return true;
+   }
+
+   explicit LzmaFileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd), lzma(nullptr) {}
+   virtual ~LzmaFileFdPrivate() { InternalClose(""); }
+#endif
+};
+									/*}}}*/
+class APT_HIDDEN PipedFileFdPrivate: public FileFdPrivate				/*{{{*/
+/* if we don't have a specific class dealing with library calls, we (un)compress
+   by executing a specified binary and pipe in/out what we need */
+{
+public:
+   virtual bool InternalOpen(int const, unsigned int const Mode) APT_OVERRIDE
+   {
+      // collect zombies here in case we reopen
+      if (compressor_pid > 0)
+	 ExecWait(compressor_pid, "FileFdCompressor", true);
+
+      if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite)
+	 return filefd->FileFdError("ReadWrite mode is not supported for file %s", filefd->FileName.c_str());
+      if (compressor.Binary == "false")
+	 return filefd->FileFdError("libapt has inbuilt support for the %s compression,"
+	       " but was forced to ignore it in favor of an external binary – which isn't installed.", compressor.Name.c_str());
+
+      bool const Comp = (Mode & FileFd::WriteOnly) == FileFd::WriteOnly;
+      if (Comp == false && filefd->iFd != -1)
+      {
+	 // Handle 'decompression' of empty files
+	 struct stat Buf;
+	 if (fstat(filefd->iFd, &Buf) != 0)
+	    return filefd->FileFdErrno("fstat", "Could not stat fd %d for file %s", filefd->iFd, filefd->FileName.c_str());
+	 if (Buf.st_size == 0 && S_ISFIFO(Buf.st_mode) == false)
+	    return true;
+
+	 // We don't need the file open - instead let the compressor open it
+	 // as he properly knows better how to efficiently read from 'his' file
+	 if (filefd->FileName.empty() == false)
+	 {
+	    close(filefd->iFd);
+	    filefd->iFd = -1;
+	 }
+      }
+
+      // Create a data pipe
+      int Pipe[2] = {-1,-1};
+      if (pipe(Pipe) != 0)
+	 return filefd->FileFdErrno("pipe",_("Failed to create subprocess IPC"));
+      for (int J = 0; J != 2; J++)
+	 SetCloseExec(Pipe[J],true);
+
+      compressed_fd = filefd->iFd;
+      set_is_pipe(true);
+
+      if (Comp == true)
+	 filefd->iFd = Pipe[1];
+      else
+	 filefd->iFd = Pipe[0];
+
+      // The child..
+      compressor_pid = ExecFork();
+      if (compressor_pid == 0)
+      {
+	 if (Comp == true)
+	 {
+	    dup2(compressed_fd,STDOUT_FILENO);
+	    dup2(Pipe[0],STDIN_FILENO);
+	 }
+	 else
+	 {
+	    if (compressed_fd != -1)
+	       dup2(compressed_fd,STDIN_FILENO);
+	    dup2(Pipe[1],STDOUT_FILENO);
+	 }
+	 int const nullfd = open("/dev/null", O_WRONLY);
+	 if (nullfd != -1)
+	 {
+	    dup2(nullfd,STDERR_FILENO);
+	    close(nullfd);
+	 }
+
+	 SetCloseExec(STDOUT_FILENO,false);
+	 SetCloseExec(STDIN_FILENO,false);
+
+	 std::vector<char const*> Args;
+	 Args.push_back(compressor.Binary.c_str());
+	 std::vector<std::string> const * const addArgs =
+	    (Comp == true) ? &(compressor.CompressArgs) : &(compressor.UncompressArgs);
+	 for (std::vector<std::string>::const_iterator a = addArgs->begin();
+	       a != addArgs->end(); ++a)
+	    Args.push_back(a->c_str());
+	 if (Comp == false && filefd->FileName.empty() == false)
+	 {
+	    // commands not needing arguments, do not need to be told about using standard output
+	    // in reality, only testcases with tools like cat, rev, rot13, … are able to trigger this
+	    if (compressor.CompressArgs.empty() == false && compressor.UncompressArgs.empty() == false)
+	       Args.push_back("--stdout");
+	    if (filefd->TemporaryFileName.empty() == false)
+	       Args.push_back(filefd->TemporaryFileName.c_str());
+	    else
+	       Args.push_back(filefd->FileName.c_str());
+	 }
+	 Args.push_back(NULL);
+
+	 execvp(Args[0],(char **)&Args[0]);
+	 cerr << _("Failed to exec compressor ") << Args[0] << endl;
+	 _exit(100);
+      }
+      if (Comp == true)
+	 close(Pipe[0]);
+      else
+	 close(Pipe[1]);
+
+      return true;
+   }
+   virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE
+   {
+      return read(filefd->iFd, To, Size);
+   }
+   virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE
+   {
+      return write(filefd->iFd, From, Size);
+   }
+   virtual bool InternalClose(std::string const &) APT_OVERRIDE
+   {
+      bool Ret = true;
+      if (filefd->iFd != -1)
+      {
+	 close(filefd->iFd);
+	 filefd->iFd = -1;
+      }
+      if (compressor_pid > 0)
+	 Ret &= ExecWait(compressor_pid, "FileFdCompressor", true);
+      compressor_pid = -1;
+      return Ret;
+   }
+   explicit PipedFileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd) {}
+   virtual ~PipedFileFdPrivate() { InternalClose(""); }
+};
+									/*}}}*/
+class APT_HIDDEN DirectFileFdPrivate: public FileFdPrivate				/*{{{*/
+{
+public:
+   virtual bool InternalOpen(int const, unsigned int const) APT_OVERRIDE { return true; }
+   virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) APT_OVERRIDE
+   {
+      return read(filefd->iFd, To, Size);
+   }
+   virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) APT_OVERRIDE
+   {
+      // files opened read+write are strange and only really "supported" for direct files
+      if (buffer.size() != 0)
+      {
+	 lseek(filefd->iFd, -buffer.size(), SEEK_CUR);
+	 buffer.reset();
+      }
+      return write(filefd->iFd, From, Size);
+   }
+   virtual bool InternalSeek(unsigned long long const To) APT_OVERRIDE
+   {
+      off_t const res = lseek(filefd->iFd, To, SEEK_SET);
+      if (res != (off_t)To)
+	 return filefd->FileFdError("Unable to seek to %llu", To);
+      seekpos = To;
+      buffer.reset();
+      return true;
+   }
+   virtual bool InternalSkip(unsigned long long Over) APT_OVERRIDE
+   {
+      if (Over >= buffer.size())
+      {
+	 Over -= buffer.size();
+	 buffer.reset();
+      }
+      else
+      {
+	 buffer.bufferstart += Over;
+	 return true;
+      }
+      if (Over == 0)
+	 return true;
+      off_t const res = lseek(filefd->iFd, Over, SEEK_CUR);
+      if (res < 0)
+	 return filefd->FileFdError("Unable to seek ahead %llu",Over);
+      seekpos = res;
+      return true;
+   }
+   virtual bool InternalTruncate(unsigned long long const To) APT_OVERRIDE
+   {
+      if (buffer.size() != 0)
+      {
+	 unsigned long long const seekpos = lseek(filefd->iFd, 0, SEEK_CUR);
+	 if ((seekpos - buffer.size()) >= To)
+	    buffer.reset();
+	 else if (seekpos >= To)
+	    buffer.bufferend = (To - seekpos) + buffer.bufferstart;
+	 else
+	    buffer.reset();
+      }
+      if (ftruncate(filefd->iFd, To) != 0)
+	 return filefd->FileFdError("Unable to truncate to %llu",To);
+      return true;
+   }
+   virtual unsigned long long InternalTell() APT_OVERRIDE
+   {
+      return lseek(filefd->iFd,0,SEEK_CUR) - buffer.size();
+   }
+   virtual unsigned long long InternalSize() APT_OVERRIDE
+   {
+      return filefd->FileSize();
+   }
+   virtual bool InternalClose(std::string const &) APT_OVERRIDE { return true; }
+   virtual bool InternalAlwaysAutoClose() const APT_OVERRIDE { return false; }
+
+   explicit DirectFileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd) {}
+   virtual ~DirectFileFdPrivate() { InternalClose(""); }
+};
+									/*}}}*/
+// FileFd Constructors							/*{{{*/
+FileFd::FileFd(std::string FileName,unsigned int const Mode,unsigned long AccessMode) : iFd(-1), Flags(0), d(NULL)
+{
+   Open(FileName,Mode, None, AccessMode);
+}
+FileFd::FileFd(std::string FileName,unsigned int const Mode, CompressMode Compress, unsigned long AccessMode) : iFd(-1), Flags(0), d(NULL)
+{
+   Open(FileName,Mode, Compress, AccessMode);
+}
+FileFd::FileFd() : iFd(-1), Flags(AutoClose), d(NULL) {}
+FileFd::FileFd(int const Fd, unsigned int const Mode, CompressMode Compress) : iFd(-1), Flags(0), d(NULL)
+{
+   OpenDescriptor(Fd, Mode, Compress);
+}
+FileFd::FileFd(int const Fd, bool const AutoClose) : iFd(-1), Flags(0), d(NULL)
+{
+   OpenDescriptor(Fd, ReadWrite, None, AutoClose);
+}
+									/*}}}*/
+// FileFd::Open - Open a file						/*{{{*/
+// ---------------------------------------------------------------------
+/* The most commonly used open mode combinations are given with Mode */
+bool FileFd::Open(string FileName,unsigned int const Mode,CompressMode Compress, unsigned long const AccessMode)
+{
+   if (Mode == ReadOnlyGzip)
+      return Open(FileName, ReadOnly, Gzip, AccessMode);
+
+   if (Compress == Auto && (Mode & WriteOnly) == WriteOnly)
+      return FileFdError("Autodetection on %s only works in ReadOnly openmode!", FileName.c_str());
+
+   std::vector<APT::Configuration::Compressor> const compressors = APT::Configuration::getCompressors();
+   std::vector<APT::Configuration::Compressor>::const_iterator compressor = compressors.begin();
+   if (Compress == Auto)
+   {
+      for (; compressor != compressors.end(); ++compressor)
+      {
+	 std::string file = FileName + compressor->Extension;
+	 if (FileExists(file) == false)
+	    continue;
+	 FileName = file;
+	 break;
+      }
+   }
+   else if (Compress == Extension)
+   {
+      std::string::size_type const found = FileName.find_last_of('.');
+      std::string ext;
+      if (found != std::string::npos)
+      {
+	 ext = FileName.substr(found);
+	 if (ext == ".new" || ext == ".bak")
+	 {
+	    std::string::size_type const found2 = FileName.find_last_of('.', found - 1);
+	    if (found2 != std::string::npos)
+	       ext = FileName.substr(found2, found - found2);
+	    else
+	       ext.clear();
+	 }
+      }
+      for (; compressor != compressors.end(); ++compressor)
+	 if (ext == compressor->Extension)
+	    break;
+      // no matching extension - assume uncompressed (imagine files like 'example.org_Packages')
+      if (compressor == compressors.end())
+	 for (compressor = compressors.begin(); compressor != compressors.end(); ++compressor)
+	    if (compressor->Name == ".")
+	       break;
+   }
+   else
+   {
+      std::string name;
+      switch (Compress)
+      {
+      case None: name = "."; break;
+      case Gzip: name = "gzip"; break;
+      case Bzip2: name = "bzip2"; break;
+      case Lzma: name = "lzma"; break;
+      case Xz: name = "xz"; break;
+      case Lz4: name = "lz4"; break;
+      case Zstd: name = "zstd"; break;
+      case Auto:
+      case Extension:
+	 // Unreachable
+	 return FileFdError("Opening File %s in None, Auto or Extension should be already handled?!?", FileName.c_str());
+      }
+      for (; compressor != compressors.end(); ++compressor)
+	 if (compressor->Name == name)
+	    break;
+      if (compressor == compressors.end())
+	 return FileFdError("Can't find a configured compressor %s for file %s", name.c_str(), FileName.c_str());
+   }
+
+   if (compressor == compressors.end())
+      return FileFdError("Can't find a match for specified compressor mode for file %s", FileName.c_str());
+   return Open(FileName, Mode, *compressor, AccessMode);
+}
+bool FileFd::Open(string FileName,unsigned int const Mode,APT::Configuration::Compressor const &compressor, unsigned long const AccessMode)
+{
+   Close();
+   Flags = AutoClose;
+
+   if ((Mode & WriteOnly) != WriteOnly && (Mode & (Atomic | Create | Empty | Exclusive)) != 0)
+      return FileFdError("ReadOnly mode for %s doesn't accept additional flags!", FileName.c_str());
+   if ((Mode & ReadWrite) == 0)
+      return FileFdError("No openmode provided in FileFd::Open for %s", FileName.c_str());
+
+   unsigned int OpenMode = Mode;
+   if (FileName == "/dev/null")
+      OpenMode = OpenMode & ~(Atomic | Exclusive | Create | Empty);
+
+   if ((OpenMode & Atomic) == Atomic)
+   {
+      Flags |= Replace;
+   }
+   else if ((OpenMode & (Exclusive | Create)) == (Exclusive | Create))
+   {
+      // for atomic, this will be done by rename in Close()
+      RemoveFile("FileFd::Open", FileName);
+   }
+   if ((OpenMode & Empty) == Empty)
+   {
+      struct stat Buf;
+      if (lstat(FileName.c_str(),&Buf) == 0 && S_ISLNK(Buf.st_mode))
+	 RemoveFile("FileFd::Open", FileName);
+   }
+
+   int fileflags = 0;
+   #define if_FLAGGED_SET(FLAG, MODE) if ((OpenMode & FLAG) == FLAG) fileflags |= MODE
+   if_FLAGGED_SET(ReadWrite, O_RDWR);
+   else if_FLAGGED_SET(ReadOnly, O_RDONLY);
+   else if_FLAGGED_SET(WriteOnly, O_WRONLY);
+
+   if_FLAGGED_SET(Create, O_CREAT);
+   if_FLAGGED_SET(Empty, O_TRUNC);
+   if_FLAGGED_SET(Exclusive, O_EXCL);
+   #undef if_FLAGGED_SET
+
+   if ((OpenMode & Atomic) == Atomic)
+   {
+      char *name = strdup((FileName + ".XXXXXX").c_str());
+
+      if((iFd = mkstemp(name)) == -1)
+      {
+          free(name);
+          return FileFdErrno("mkstemp", "Could not create temporary file for %s", FileName.c_str());
+      }
+
+      TemporaryFileName = string(name);
+      free(name);
+
+      // umask() will always set the umask and return the previous value, so
+      // we first set the umask and then reset it to the old value
+      mode_t const CurrentUmask = umask(0);
+      umask(CurrentUmask);
+      // calculate the actual file permissions (just like open/creat)
+      mode_t const FilePermissions = (AccessMode & ~CurrentUmask);
+
+      if(fchmod(iFd, FilePermissions) == -1)
+          return FileFdErrno("fchmod", "Could not change permissions for temporary file %s", TemporaryFileName.c_str());
+   }
+   else
+      iFd = open(FileName.c_str(), fileflags, AccessMode);
+
+   this->FileName = FileName;
+   if (iFd == -1 || OpenInternDescriptor(OpenMode, compressor) == false)
+   {
+      if (iFd != -1)
+      {
+	 close (iFd);
+	 iFd = -1;
+      }
+      return FileFdErrno("open",_("Could not open file %s"), FileName.c_str());
+   }
+
+   SetCloseExec(iFd,true);
+   return true;
+}
+									/*}}}*/
+// FileFd::OpenDescriptor - Open a filedescriptor			/*{{{*/
+bool FileFd::OpenDescriptor(int Fd, unsigned int const Mode, CompressMode Compress, bool AutoClose)
+{
+   std::vector<APT::Configuration::Compressor> const compressors = APT::Configuration::getCompressors();
+   std::vector<APT::Configuration::Compressor>::const_iterator compressor = compressors.begin();
+   std::string name;
+
+   // compat with the old API
+   if (Mode == ReadOnlyGzip && Compress == None)
+      Compress = Gzip;
+
+   switch (Compress)
+   {
+   case None: name = "."; break;
+   case Gzip: name = "gzip"; break;
+   case Bzip2: name = "bzip2"; break;
+   case Lzma: name = "lzma"; break;
+   case Xz: name = "xz"; break;
+   case Lz4: name = "lz4"; break;
+   case Zstd: name = "zstd"; break;
+   case Auto:
+   case Extension:
+      if (AutoClose == true && Fd != -1)
+	 close(Fd);
+      return FileFdError("Opening Fd %d in Auto or Extension compression mode is not supported", Fd);
+   }
+   for (; compressor != compressors.end(); ++compressor)
+      if (compressor->Name == name)
+	 break;
+   if (compressor == compressors.end())
+   {
+      if (AutoClose == true && Fd != -1)
+	 close(Fd);
+      return FileFdError("Can't find a configured compressor %s for file %s", name.c_str(), FileName.c_str());
+   }
+   return OpenDescriptor(Fd, Mode, *compressor, AutoClose);
+}
+bool FileFd::OpenDescriptor(int Fd, unsigned int const Mode, APT::Configuration::Compressor const &compressor, bool AutoClose)
+{
+   Close();
+   Flags = (AutoClose) ? FileFd::AutoClose : 0;
+   iFd = Fd;
+   this->FileName = "";
+   if (OpenInternDescriptor(Mode, compressor) == false)
+   {
+      if (iFd != -1 && (
+	(Flags & Compressed) == Compressed ||
+	AutoClose == true))
+      {
+	 close (iFd);
+	 iFd = -1;
+      }
+      return FileFdError(_("Could not open file descriptor %d"), Fd);
+   }
+   return true;
+}
+bool FileFd::OpenInternDescriptor(unsigned int const Mode, APT::Configuration::Compressor const &compressor)
+{
+   if (iFd == -1)
+      return false;
+
+   if (d != nullptr)
+      d->InternalClose(FileName);
+
+   if (d == nullptr)
+   {
+      if (false)
+	 /* dummy so that the rest can be 'else if's */;
+#define APT_COMPRESS_INIT(NAME, CONSTRUCTOR) \
+      else if (compressor.Name == NAME) \
+	 d = new CONSTRUCTOR(this)
+#ifdef HAVE_ZLIB
+      APT_COMPRESS_INIT("gzip", GzipFileFdPrivate);
+#endif
+#ifdef HAVE_BZ2
+      APT_COMPRESS_INIT("bzip2", Bz2FileFdPrivate);
+#endif
+#ifdef HAVE_LZMA
+      APT_COMPRESS_INIT("xz", LzmaFileFdPrivate);
+      APT_COMPRESS_INIT("lzma", LzmaFileFdPrivate);
+#endif
+#ifdef HAVE_LZ4
+      APT_COMPRESS_INIT("lz4", Lz4FileFdPrivate);
+#endif
+#ifdef HAVE_ZSTD
+      APT_COMPRESS_INIT("zstd", ZstdFileFdPrivate);
+#endif
+#undef APT_COMPRESS_INIT
+      else if (compressor.Name == "." || compressor.Binary.empty() == true)
+	 d = new DirectFileFdPrivate(this);
+      else
+	 d = new PipedFileFdPrivate(this);
+
+      if (Mode & BufferedWrite)
+	 d = new BufferedWriteFileFdPrivate(d);
+
+      d->set_openmode(Mode);
+      d->set_compressor(compressor);
+      if ((Flags & AutoClose) != AutoClose && d->InternalAlwaysAutoClose())
+      {
+	 // Need to duplicate fd here or gz/bz2 close for cleanup will close the fd as well
+	 int const internFd = dup(iFd);
+	 if (internFd == -1)
+	    return FileFdErrno("OpenInternDescriptor", _("Could not open file descriptor %d"), iFd);
+	 iFd = internFd;
+      }
+   }
+   return d->InternalOpen(iFd, Mode);
+}
+									/*}}}*/
+// FileFd::~File - Closes the file					/*{{{*/
+// ---------------------------------------------------------------------
+/* If the proper modes are selected then we close the Fd and possibly
+   unlink the file on error. */
+FileFd::~FileFd()
+{
+   Close();
+   if (d != NULL)
+      d->InternalClose(FileName);
+   delete d;
+   d = NULL;
+}
+									/*}}}*/
+// FileFd::Read - Read a bit of the file				/*{{{*/
+// ---------------------------------------------------------------------
+/* We are careful to handle interruption by a signal while reading
+   gracefully. */
+bool FileFd::Read(void *To,unsigned long long Size,unsigned long long *Actual)
+{
+   if (d == nullptr || Failed())
+      return false;
+   ssize_t Res = 1;
+   errno = 0;
+   if (Actual != 0)
+      *Actual = 0;
+   *((char *)To) = '\0';
+   while (Res > 0 && Size > 0)
+   {
+      Res = d->InternalRead(To, Size);
+
+      if (Res < 0)
+      {
+	 if (errno == EINTR)
+	 {
+	    // trick the while-loop into running again
+	    Res = 1;
+	    errno = 0;
+	    continue;
+	 }
+	 return d->InternalReadError();
+      }
+      
+      To = (char *)To + Res;
+      Size -= Res;
+      if (d != NULL)
+	 d->set_seekpos(d->get_seekpos() + Res);
+      if (Actual != 0)
+	 *Actual += Res;
+   }
+   
+   if (Size == 0)
+      return true;
+   
+   // Eof handling
+   if (Actual != 0)
+   {
+      Flags |= HitEof;
+      return true;
+   }
+
+   return FileFdError(_("read, still have %llu to read but none left"), Size);
+}
+bool FileFd::Read(int const Fd, void *To, unsigned long long Size, unsigned long long * const Actual)
+{
+   ssize_t Res = 1;
+   errno = 0;
+   if (Actual != nullptr)
+      *Actual = 0;
+   *static_cast<char *>(To) = '\0';
+   while (Res > 0 && Size > 0)
+   {
+      Res = read(Fd, To, Size);
+      if (Res < 0)
+      {
+	 if (errno == EINTR)
+	 {
+	    Res = 1;
+	    errno = 0;
+	    continue;
+	 }
+	 return _error->Errno("read", _("Read error"));
+      }
+      To = static_cast<char *>(To) + Res;
+      Size -= Res;
+      if (Actual != 0)
+	 *Actual += Res;
+   }
+   if (Size == 0)
+      return true;
+   if (Actual != nullptr)
+      return true;
+   return _error->Error(_("read, still have %llu to read but none left"), Size);
+}
+									/*}}}*/
+// FileFd::ReadLine - Read a complete line from the file		/*{{{*/
+char* FileFd::ReadLine(char *To, unsigned long long const Size)
+{
+   *To = '\0';
+   if (d == nullptr || Failed())
+      return nullptr;
+   return d->InternalReadLine(To, Size);
+}
+bool FileFd::ReadLine(std::string &To)
+{
+   To.clear();
+   if (d == nullptr || Failed())
+      return false;
+   constexpr size_t buflen = 4096;
+   char buffer[buflen];
+   size_t len;
+   do
+   {
+      if (d->InternalReadLine(buffer, buflen) == nullptr)
+	 return false;
+      len = strlen(buffer);
+      To.append(buffer, len);
+   } while (len == buflen - 1 && buffer[len - 2] != '\n');
+   // remove the newline at the end
+   auto const i = To.find_last_not_of("\r\n");
+   if (i == std::string::npos)
+      To.clear();
+   else
+      To.erase(i + 1);
+   return true;
+}
+									/*}}}*/
+// FileFd::Flush - Flush the file  					/*{{{*/
+bool FileFd::Flush()
+{
+   if (Failed())
+      return false;
+   if (d == nullptr)
+      return true;
+
+   return d->InternalFlush();
+}
+									/*}}}*/
+// FileFd::Write - Write to the file					/*{{{*/
+bool FileFd::Write(const void *From,unsigned long long Size)
+{
+   if (d == nullptr || Failed())
+      return false;
+   ssize_t Res = 1;
+   errno = 0;
+   while (Res > 0 && Size > 0)
+   {
+      Res = d->InternalWrite(From, Size);
+
+      if (Res < 0)
+      {
+	 if (errno == EINTR)
+	 {
+	    // trick the while-loop into running again
+	    Res = 1;
+	    errno = 0;
+	    continue;
+	 }
+	 return d->InternalWriteError();
+      }
+
+      From = (char const *)From + Res;
+      Size -= Res;
+      if (d != NULL)
+	 d->set_seekpos(d->get_seekpos() + Res);
+   }
+
+   if (Size == 0)
+      return true;
+
+   return FileFdError(_("write, still have %llu to write but couldn't"), Size);
+}
+bool FileFd::Write(int Fd, const void *From, unsigned long long Size)
+{
+   ssize_t Res = 1;
+   errno = 0;
+   while (Res > 0 && Size > 0)
+   {
+      Res = write(Fd,From,Size);
+      if (Res < 0 && errno == EINTR)
+	 continue;
+      if (Res < 0)
+	 return _error->Errno("write",_("Write error"));
+
+      From = (char const *)From + Res;
+      Size -= Res;
+   }
+
+   if (Size == 0)
+      return true;
+
+   return _error->Error(_("write, still have %llu to write but couldn't"), Size);
+}
+									/*}}}*/
+// FileFd::Seek - Seek in the file					/*{{{*/
+bool FileFd::Seek(unsigned long long To)
+{
+   if (d == nullptr || Failed())
+      return false;
+   Flags &= ~HitEof;
+   return d->InternalSeek(To);
+}
+									/*}}}*/
+// FileFd::Skip - Skip over data in the file				/*{{{*/
+bool FileFd::Skip(unsigned long long Over)
+{
+   if (d == nullptr || Failed())
+      return false;
+   return d->InternalSkip(Over);
+}
+									/*}}}*/
+// FileFd::Truncate - Truncate the file					/*{{{*/
+bool FileFd::Truncate(unsigned long long To)
+{
+   if (d == nullptr || Failed())
+      return false;
+   // truncating /dev/null is always successful - as we get an error otherwise
+   if (To == 0 && FileName == "/dev/null")
+      return true;
+   return d->InternalTruncate(To);
+}
+									/*}}}*/
+// FileFd::Tell - Current seek position					/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+unsigned long long FileFd::Tell()
+{
+   if (d == nullptr || Failed())
+      return false;
+   off_t const Res = d->InternalTell();
+   if (Res == (off_t)-1)
+      FileFdErrno("lseek","Failed to determine the current file position");
+   d->set_seekpos(Res);
+   return Res;
+}
+									/*}}}*/
+static bool StatFileFd(char const * const msg, int const iFd, std::string const &FileName, struct stat &Buf, FileFdPrivate * const d) /*{{{*/
+{
+   bool ispipe = (d != NULL && d->get_is_pipe() == true);
+   if (ispipe == false)
+   {
+      if (fstat(iFd,&Buf) != 0)
+	 // higher-level code will generate more meaningful messages,
+	 // even translated this would be meaningless for users
+	 return _error->Errno("fstat", "Unable to determine %s for fd %i", msg, iFd);
+      if (FileName.empty() == false)
+	 ispipe = S_ISFIFO(Buf.st_mode);
+   }
+
+   // for compressor pipes st_size is undefined and at 'best' zero
+   if (ispipe == true)
+   {
+      // we set it here, too, as we get the info here for free
+      // in theory the Open-methods should take care of it already
+      if (d != NULL)
+	 d->set_is_pipe(true);
+      if (stat(FileName.c_str(), &Buf) != 0)
+	 return _error->Errno("fstat", "Unable to determine %s for file %s", msg, FileName.c_str());
+   }
+   return true;
+}
+									/*}}}*/
+// FileFd::FileSize - Return the size of the file			/*{{{*/
+unsigned long long FileFd::FileSize()
+{
+   struct stat Buf;
+   if (StatFileFd("file size", iFd, FileName, Buf, d) == false)
+   {
+      Flags |= Fail;
+      return 0;
+   }
+   return Buf.st_size;
+}
+									/*}}}*/
+// FileFd::ModificationTime - Return the time of last touch		/*{{{*/
+time_t FileFd::ModificationTime()
+{
+   struct stat Buf;
+   if (StatFileFd("modification time", iFd, FileName, Buf, d) == false)
+   {
+      Flags |= Fail;
+      return 0;
+   }
+   return Buf.st_mtime;
+}
+									/*}}}*/
+// FileFd::Size - Return the size of the content in the file		/*{{{*/
+unsigned long long FileFd::Size()
+{
+   if (d == nullptr)
+      return 0;
+   return d->InternalSize();
+}
+									/*}}}*/
+// FileFd::Close - Close the file if the close flag is set		/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool FileFd::Close()
+{
+   if (Failed() == false && Flush() == false)
+      return false;
+   if (iFd == -1)
+      return true;
+
+   bool Res = true;
+   if ((Flags & AutoClose) == AutoClose)
+   {
+      if ((Flags & Compressed) != Compressed && iFd > 0 && close(iFd) != 0)
+	 Res &= _error->Errno("close",_("Problem closing the file %s"), FileName.c_str());
+   }
+
+   if (d != NULL)
+   {
+      Res &= d->InternalClose(FileName);
+      delete d;
+      d = NULL;
+   }
+
+   if ((Flags & Replace) == Replace) {
+      if (Failed() == false && rename(TemporaryFileName.c_str(), FileName.c_str()) != 0)
+	 Res &= _error->Errno("rename",_("Problem renaming the file %s to %s"), TemporaryFileName.c_str(), FileName.c_str());
+
+      FileName = TemporaryFileName; // for the unlink() below.
+      TemporaryFileName.clear();
+   }
+
+   iFd = -1;
+
+   if ((Flags & Fail) == Fail && (Flags & DelOnFail) == DelOnFail &&
+       FileName.empty() == false)
+      Res &= RemoveFile("FileFd::Close", FileName);
+
+   if (Res == false)
+      Flags |= Fail;
+   return Res;
+}
+									/*}}}*/
+// FileFd::Sync - Sync the file						/*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool FileFd::Sync()
+{
+   if (fsync(iFd) != 0)
+      return FileFdErrno("sync",_("Problem syncing the file"));
+   return true;
+}
+									/*}}}*/
+// FileFd::FileFdErrno - set Fail and call _error->Errno		*{{{*/
+bool FileFd::FileFdErrno(const char *Function, const char *Description,...)
+{
+   Flags |= Fail;
+   va_list args;
+   size_t msgSize = 400;
+   int const errsv = errno;
+   bool retry;
+   do {
+      va_start(args,Description);
+      retry = _error->InsertErrno(GlobalError::ERROR, Function, Description, args, errsv, msgSize);
+      va_end(args);
+   } while (retry);
+   return false;
+}
+									/*}}}*/
+// FileFd::FileFdError - set Fail and call _error->Error		*{{{*/
+bool FileFd::FileFdError(const char *Description,...) {
+   Flags |= Fail;
+   va_list args;
+   size_t msgSize = 400;
+   bool retry;
+   do {
+      va_start(args,Description);
+      retry = _error->Insert(GlobalError::ERROR, Description, args, msgSize);
+      va_end(args);
+   } while (retry);
+   return false;
+}
+									/*}}}*/
+gzFile FileFd::gzFd() {							/*{{{*/
+#ifdef HAVE_ZLIB
+   GzipFileFdPrivate * const gzipd = dynamic_cast<GzipFileFdPrivate*>(d);
+   if (gzipd == nullptr)
+      return nullptr;
+   else
+      return gzipd->gz;
+#else
+   return nullptr;
+#endif
+}
+									/*}}}*/
+
+// Glob - wrapper around "glob()"					/*{{{*/
+std::vector<std::string> Glob(std::string const &pattern, int flags)
+{
+   std::vector<std::string> result;
+   glob_t globbuf;
+   int glob_res;
+   unsigned int i;
+
+   glob_res = glob(pattern.c_str(),  flags, NULL, &globbuf);
+
+   if (glob_res != 0)
+   {
+      if(glob_res != GLOB_NOMATCH) {
+         _error->Errno("glob", "Problem with glob");
+         return result;
+      }
+   }
+
+   // append results
+   for(i=0;i<globbuf.gl_pathc;i++)
+      result.push_back(string(globbuf.gl_pathv[i]));
+
+   globfree(&globbuf);
+   return result;
+}
+									/*}}}*/
+static std::string APT_NONNULL(1) GetTempDirEnv(char const * const env)	/*{{{*/
+{
+   const char *tmpdir = getenv(env);
+
+#ifdef P_tmpdir
+   if (!tmpdir)
+      tmpdir = P_tmpdir;
+#endif
+
+   struct stat st;
+   if (!tmpdir || strlen(tmpdir) == 0 || // tmpdir is set
+	 stat(tmpdir, &st) != 0 || (st.st_mode & S_IFDIR) == 0) // exists and is directory
+      tmpdir = "/tmp";
+   else if (geteuid() != 0 && // root can do everything anyway
+	 faccessat(AT_FDCWD, tmpdir, R_OK | W_OK | X_OK, AT_EACCESS) != 0) // current user has rwx access to directory
+      tmpdir = "/tmp";
+
+   return string(tmpdir);
+}
+									/*}}}*/
+std::string GetTempDir()						/*{{{*/
+{
+   return GetTempDirEnv("TMPDIR");
+}
+std::string GetTempDir(std::string const &User)
+{
+   // no need/possibility to drop privs
+   if(getuid() != 0 || User.empty() || User == "root")
+      return GetTempDir();
+
+   struct passwd const * const pw = getpwnam(User.c_str());
+   if (pw == NULL)
+      return GetTempDir();
+
+   gid_t const old_euid = geteuid();
+   gid_t const old_egid = getegid();
+   if (setegid(pw->pw_gid) != 0)
+      _error->Errno("setegid", "setegid %u failed", pw->pw_gid);
+   if (seteuid(pw->pw_uid) != 0)
+      _error->Errno("seteuid", "seteuid %u failed", pw->pw_uid);
+
+   std::string const tmp = GetTempDir();
+
+   if (seteuid(old_euid) != 0)
+      _error->Errno("seteuid", "seteuid %u failed", old_euid);
+   if (setegid(old_egid) != 0)
+      _error->Errno("setegid", "setegid %u failed", old_egid);
+
+   return tmp;
+}
+									/*}}}*/
+FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink, FileFd * const TmpFd)	/*{{{*/
+{
+   return GetTempFile(Prefix, ImmediateUnlink, TmpFd, false);
+}
+FileFd* GetTempFile(std::string const &Prefix, bool ImmediateUnlink, FileFd * const TmpFd, bool Buffered)
+{
+   char fn[512];
+   FileFd * const Fd = TmpFd == nullptr ? new FileFd() : TmpFd;
+
+   std::string const tempdir = GetTempDir();
+   snprintf(fn, sizeof(fn), "%s/%s.XXXXXX",
+            tempdir.c_str(), Prefix.c_str());
+   int const fd = mkstemp(fn);
+   if (ImmediateUnlink)
+      unlink(fn);
+   if (fd < 0)
+   {
+      _error->Errno("GetTempFile",_("Unable to mkstemp %s"), fn);
+      if (TmpFd == nullptr)
+	 delete Fd;
+      return nullptr;
+   }
+   if (!Fd->OpenDescriptor(fd, FileFd::ReadWrite | (Buffered ? FileFd::BufferedWrite : 0), FileFd::None, true))
+   {
+      _error->Errno("GetTempFile",_("Unable to write to %s"),fn);
+      if (TmpFd == nullptr)
+	 delete Fd;
+      return nullptr;
+   }
+   if (ImmediateUnlink == false)
+      Fd->SetFileName(fn);
+   return Fd;
+}
+									/*}}}*/
+bool Rename(std::string From, std::string To)				/*{{{*/
+{
+   if (rename(From.c_str(),To.c_str()) != 0)
+   {
+      _error->Error(_("rename failed, %s (%s -> %s)."),strerror(errno),
+                    From.c_str(),To.c_str());
+      return false;
+   }
+   return true;
+}
+									/*}}}*/
+bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode)/*{{{*/
+{
+   return Popen(Args, Fd, Child, Mode, true);
+}
+									/*}}}*/
+bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode, bool CaptureStderr)/*{{{*/
+{
+   return Popen(Args, Fd, Child, Mode, CaptureStderr, false);
+}
+									/*}}}*/
+bool Popen(const char *Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode, bool CaptureStderr, bool Sandbox) /*{{{*/
+{
+   int fd;
+   if (Mode != FileFd::ReadOnly && Mode != FileFd::WriteOnly)
+      return _error->Error("Popen supports ReadOnly (x)or WriteOnly mode only");
+
+   int Pipe[2] = {-1, -1};
+   if(pipe(Pipe) != 0)
+      return _error->Errno("pipe", _("Failed to create subprocess IPC"));
+
+   std::set<int> keep_fds;
+   keep_fds.insert(Pipe[0]);
+   keep_fds.insert(Pipe[1]);
+   Child = ExecFork(keep_fds);
+   if(Child < 0)
+      return _error->Errno("fork", "Failed to fork");
+   if(Child == 0)
+   {
+      if (Sandbox && (getuid() == 0 || geteuid() == 0) && !DropPrivileges())
+      {
+	 _error->DumpErrors();
+	 _exit(1);
+      }
+      if(Mode == FileFd::ReadOnly)
+      {
+         close(Pipe[0]);
+         fd = Pipe[1];
+      }
+      else if(Mode == FileFd::WriteOnly)
+      {
+         close(Pipe[1]);
+         fd = Pipe[0];
+      }
+
+      if(Mode == FileFd::ReadOnly)
+      {
+         dup2(fd, 1);
+	 if (CaptureStderr == true)
+	    dup2(fd, 2);
+      } else if(Mode == FileFd::WriteOnly)
+         dup2(fd, 0);
+
+      execv(Args[0], (char**)Args);
+      _exit(100);
+   }
+   if(Mode == FileFd::ReadOnly)
+   {
+      close(Pipe[1]);
+      fd = Pipe[0];
+   }
+   else if(Mode == FileFd::WriteOnly)
+   {
+      close(Pipe[0]);
+      fd = Pipe[1];
+   }
+   else
+      return _error->Error("Popen supports ReadOnly (x)or WriteOnly mode only");
+   Fd.OpenDescriptor(fd, Mode, FileFd::None, true);
+
+   return true;
+}
+									/*}}}*/
+bool DropPrivileges()							/*{{{*/
+{
+   if(_config->FindB("Debug::NoDropPrivs", false) == true)
+      return true;
+
+#if __gnu_linux__
+#if defined(PR_SET_NO_NEW_PRIVS) && ( PR_SET_NO_NEW_PRIVS != 38 )
+#error "PR_SET_NO_NEW_PRIVS is defined, but with a different value than expected!"
+#endif
+   // see prctl(2), needs linux3.5 at runtime - magic constant to avoid it at buildtime
+   int ret = prctl(38, 1, 0, 0, 0);
+   // ignore EINVAL - kernel is too old to understand the option
+   if(ret < 0 && errno != EINVAL)
+      _error->Warning("PR_SET_NO_NEW_PRIVS failed with %i", ret);
+#endif
+
+   // empty setting disables privilege dropping - this also ensures
+   // backward compatibility, see bug #764506
+   const std::string toUser = _config->Find("APT::Sandbox::User");
+   if (toUser.empty() || toUser == "root")
+      return true;
+
+   // a lot can go wrong trying to drop privileges completely,
+   // so ideally we would like to verify that we have done it –
+   // but the verify asks for too much in case of fakeroot (and alike)
+   // [Specific checks can be overridden with dedicated options]
+   bool const VerifySandboxing = _config->FindB("APT::Sandbox::Verify", false);
+
+   // uid will be 0 in the end, but gid might be different anyway
+   uid_t const old_uid = getuid();
+   gid_t const old_gid = getgid();
+
+   if (old_uid != 0)
+      return true;
+
+   struct passwd *pw = getpwnam(toUser.c_str());
+   if (pw == NULL)
+      return _error->Error("No user %s, can not drop rights", toUser.c_str());
+
+   // Do not change the order here, it might break things
+   // Get rid of all our supplementary groups first
+   if (setgroups(1, &pw->pw_gid))
+      return _error->Errno("setgroups", "Failed to setgroups");
+
+   // Now change the group ids to the new user
+#ifdef HAVE_SETRESGID
+   if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0)
+      return _error->Errno("setresgid", "Failed to set new group ids");
+#else
+   if (setegid(pw->pw_gid) != 0)
+      return _error->Errno("setegid", "Failed to setegid");
+
+   if (setgid(pw->pw_gid) != 0)
+      return _error->Errno("setgid", "Failed to setgid");
+#endif
+
+   // Change the user ids to the new user
+#ifdef HAVE_SETRESUID
+   if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0)
+      return _error->Errno("setresuid", "Failed to set new user ids");
+#else
+   if (setuid(pw->pw_uid) != 0)
+      return _error->Errno("setuid", "Failed to setuid");
+   if (seteuid(pw->pw_uid) != 0)
+      return _error->Errno("seteuid", "Failed to seteuid");
+#endif
+
+   // disabled by default as fakeroot doesn't implement getgroups currently (#806521)
+   if (VerifySandboxing == true || _config->FindB("APT::Sandbox::Verify::Groups", false) == true)
+   {
+      // Verify that the user isn't still in any supplementary groups
+      long const ngroups_max = sysconf(_SC_NGROUPS_MAX);
+      std::unique_ptr<gid_t[]> gidlist(new gid_t[ngroups_max]);
+      if (unlikely(gidlist == NULL))
+	 return _error->Error("Allocation of a list of size %lu for getgroups failed", ngroups_max);
+      ssize_t gidlist_nr;
+      if ((gidlist_nr = getgroups(ngroups_max, gidlist.get())) < 0)
+	 return _error->Errno("getgroups", "Could not get new groups (%lu)", ngroups_max);
+      for (ssize_t i = 0; i < gidlist_nr; ++i)
+	 if (gidlist[i] != pw->pw_gid)
+	    return _error->Error("Could not switch group, user %s is still in group %d", toUser.c_str(), gidlist[i]);
+   }
+
+   // enabled by default as all fakeroot-lookalikes should fake that accordingly
+   if (VerifySandboxing == true || _config->FindB("APT::Sandbox::Verify::IDs", true) == true)
+   {
+      // Verify that gid, egid, uid, and euid changed
+      if (getgid() != pw->pw_gid)
+	 return _error->Error("Could not switch group");
+      if (getegid() != pw->pw_gid)
+	 return _error->Error("Could not switch effective group");
+      if (getuid() != pw->pw_uid)
+	 return _error->Error("Could not switch user");
+      if (geteuid() != pw->pw_uid)
+	 return _error->Error("Could not switch effective user");
+
+#ifdef HAVE_GETRESUID
+      // verify that the saved set-user-id was changed as well
+      uid_t ruid = 0;
+      uid_t euid = 0;
+      uid_t suid = 0;
+      if (getresuid(&ruid, &euid, &suid))
+	 return _error->Errno("getresuid", "Could not get saved set-user-ID");
+      if (suid != pw->pw_uid)
+	 return _error->Error("Could not switch saved set-user-ID");
+#endif
+
+#ifdef HAVE_GETRESGID
+      // verify that the saved set-group-id was changed as well
+      gid_t rgid = 0;
+      gid_t egid = 0;
+      gid_t sgid = 0;
+      if (getresgid(&rgid, &egid, &sgid))
+	 return _error->Errno("getresuid", "Could not get saved set-group-ID");
+      if (sgid != pw->pw_gid)
+	 return _error->Error("Could not switch saved set-group-ID");
+#endif
+   }
+
+   // disabled as fakeroot doesn't forbid (by design) (re)gaining root from unprivileged
+   if (VerifySandboxing == true || _config->FindB("APT::Sandbox::Verify::Regain", false) == true)
+   {
+      // Check that uid and gid changes do not work anymore
+      if (pw->pw_gid != old_gid && (setgid(old_gid) != -1 || setegid(old_gid) != -1))
+	 return _error->Error("Could restore a gid to root, privilege dropping did not work");
+
+      if (pw->pw_uid != old_uid && (setuid(old_uid) != -1 || seteuid(old_uid) != -1))
+	 return _error->Error("Could restore a uid to root, privilege dropping did not work");
+   }
+
+   if (_config->FindB("APT::Sandbox::ResetEnvironment", true))
+   {
+      setenv("HOME", pw->pw_dir, 1);
+      setenv("USER", pw->pw_name, 1);
+      setenv("USERNAME", pw->pw_name, 1);
+      setenv("LOGNAME", pw->pw_name, 1);
+      auto const shell = flNotDir(pw->pw_shell);
+      if (shell == "false" || shell == "nologin")
+	 setenv("SHELL", "/bin/sh", 1);
+      else
+	 setenv("SHELL", pw->pw_shell, 1);
+      auto const apt_setenv_tmp = [](char const * const env) {
+	 auto const tmpdir = getenv(env);
+	 if (tmpdir != nullptr)
+	 {
+	    auto const ourtmpdir = GetTempDirEnv(env);
+	    if (ourtmpdir != tmpdir)
+	       setenv(env, ourtmpdir.c_str(), 1);
+	 }
+      };
+      apt_setenv_tmp("TMPDIR");
+      apt_setenv_tmp("TEMPDIR");
+      apt_setenv_tmp("TMP");
+      apt_setenv_tmp("TEMP");
+   }
+
+   return true;
+}
+									/*}}}*/
+bool OpenConfigurationFileFd(std::string const &File, FileFd &Fd) /*{{{*/
+{
+   int const fd = open(File.c_str(), O_RDONLY | O_CLOEXEC | O_NOCTTY);
+   if (fd == -1)
+      return _error->WarningE("open", _("Unable to read %s"), File.c_str());
+   APT::Configuration::Compressor none(".", "", "", nullptr, nullptr, 0);
+   if (Fd.OpenDescriptor(fd, FileFd::ReadOnly, none, true) == false)
+      return false;
+   Fd.SetFileName(File);
+   return true;
+}
+									/*}}}*/
+int Inhibit(const char *what, const char *who, const char *why, const char *mode) /*{{{*/
+{
+#ifdef HAVE_SYSTEMD
+   sd_bus_error error = SD_BUS_ERROR_NULL;
+   sd_bus_message *m = NULL;
+   sd_bus *bus = NULL;
+   int fd;
+   int r;
+
+   r = sd_bus_open_system(&bus);
+   if (r < 0)
+      goto out;
+
+   r = sd_bus_call_method(bus,
+			  "org.freedesktop.login1",
+			  "/org/freedesktop/login1",
+			  "org.freedesktop.login1.Manager",
+			  "Inhibit",
+			  &error,
+			  &m,
+			  "ssss",
+			  what,
+			  who,
+			  why,
+			  mode);
+   if (r < 0)
+      goto out;
+
+   r = sd_bus_message_read(m, "h", &fd);
+   if (r < 0)
+      goto out;
+
+   // We received a file descriptor, return it - systemd will close the read fd
+   // on free, so let's duplicate it here.
+   r = dup(fd);
+out:
+   sd_bus_error_free(&error);
+   sd_bus_message_unref(m);
+   sd_bus_unref(bus);
+   return r;
+#else
+   return -ENOTSUP;
+#endif
+}
+									/*}}}*/