clean archives without changing directory

Adopting this change in other frontends will require source changes as
well similar to our own changes in apt-private/.

3 files changed, 47 insertions, 25 deletions

diff --git a/apt-pkg/clean.cc b/apt-pkg/clean.cc
index fe57c26a2..9f408e46e 100644
--- a/apt-pkg/clean.cc
+++ b/apt-pkg/clean.cc
@@ -22,8 +22,10 @@
 #include <string>
 #include <string.h>
 #include <dirent.h>
+#include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
+#include <fcntl.h>
 
 #include <apti18n.h>
 									/*}}}*/
@@ -43,17 +45,21 @@ bool pkgArchiveCleaner::Go(std::string Dir,pkgCache &Cache)
    if (FileExists(Dir) == false)
       return true;
 
-   DIR *D = opendir(Dir.c_str());
-   if (D == 0)
-      return _error->Errno("opendir",_("Unable to read %s"),Dir.c_str());
-
-   std::string StartDir = SafeGetCWD();
-   if (chdir(Dir.c_str()) != 0)
+   auto const withoutChangingDir = dynamic_cast<pkgArchiveCleaner2*>(this);
+   int const dirfd = open(Dir.c_str(), O_RDONLY | O_DIRECTORY | O_CLOEXEC);
+   if (dirfd == -1)
+      return _error->Errno("open",_("Unable to read %s"),Dir.c_str());
+   std::string CWD;
+   if (withoutChangingDir == nullptr)
    {
-      closedir(D);
-      return _error->Errno("chdir",_("Unable to change to %s"),Dir.c_str());
+      CWD = SafeGetCWD();
+      if (fchdir(dirfd) != 0)
+	 return _error->Errno("fchdir",_("Unable to change to %s"),Dir.c_str());
    }
-   
+   DIR * const D = fdopendir(dirfd);
+   if (D == nullptr)
+      return _error->Errno("opendir",_("Unable to read %s"),Dir.c_str());
+
    for (struct dirent *Dir = readdir(D); Dir != 0; Dir = readdir(D))
    {
       // Skip some files..
@@ -65,15 +71,13 @@ bool pkgArchiveCleaner::Go(std::string Dir,pkgCache &Cache)
 	 continue;
 
       struct stat St;
-      if (stat(Dir->d_name,&St) != 0)
+      if (fstatat(dirfd, Dir->d_name,&St, 0) != 0)
       {
 	 _error->Errno("stat",_("Unable to stat %s."),Dir->d_name);
 	 closedir(D);
-	 if (chdir(StartDir.c_str()) != 0)
-	    return _error->Errno("chdir", _("Unable to change to %s"), StartDir.c_str());
 	 return false;
       }
-      
+
       // Grab the package name
       const char *I = Dir->d_name;
       for (; *I != 0 && *I != '_';I++);
@@ -87,7 +91,7 @@ bool pkgArchiveCleaner::Go(std::string Dir,pkgCache &Cache)
       if (*I != '_')
 	 continue;
       std::string Ver = DeQuoteString(std::string(Start,I-Start));
-  
+
       // Grab the arch
       Start = I + 1;
       for (I = Start; *I != 0 && *I != '.' ;I++);
@@ -98,7 +102,7 @@ bool pkgArchiveCleaner::Go(std::string Dir,pkgCache &Cache)
       // ignore packages of unconfigured architectures
       if (APT::Configuration::checkArchitecture(Arch) == false)
 	 continue;
-      
+
       // Lookup the package
       pkgCache::PkgIterator P = Cache.FindPkg(Pkg, Arch);
       if (P.end() != true)
@@ -117,23 +121,29 @@ bool pkgArchiveCleaner::Go(std::string Dir,pkgCache &Cache)
 	       IsFetchable = true;
 	       break;
 	    }
-	    
+
 	    // See if this version matches the file
 	    if (IsFetchable == true && Ver == V.VerStr())
 	       break;
 	 }
-	 
+
 	 // We found a match, keep the file
 	 if (V.end() == false)
 	    continue;
       }
-            
-      Erase(Dir->d_name,Pkg,Ver,St);
-   };
-   
+
+      if (withoutChangingDir == nullptr)
+      {
+	 APT_IGNORE_DEPRECATED_PUSH
+	 Erase(Dir->d_name, Pkg, Ver, St);
+	 APT_IGNORE_DEPRECATED_POP
+      }
+      else
+	 withoutChangingDir->Erase(dirfd, Dir->d_name, Pkg, Ver, St);
+   }
    closedir(D);
-   if (chdir(StartDir.c_str()) != 0)
-      return _error->Errno("chdir", _("Unable to change to %s"), StartDir.c_str());
+   if (withoutChangingDir == nullptr && chdir(CWD.c_str()) != 0)
+      return _error->Errno("chdir", _("Unable to change to %s"),Dir.c_str());
    return true;
 }
 									/*}}}*/
diff --git a/apt-pkg/clean.h b/apt-pkg/clean.h
index 6cedae086..2ba3932a0 100644
--- a/apt-pkg/clean.h
+++ b/apt-pkg/clean.h
@@ -16,6 +16,8 @@
 
 #include <string>
 
+#include <apt-pkg/macros.h>
+
 class pkgCache;
 
 class pkgArchiveCleaner
@@ -25,7 +27,7 @@ class pkgArchiveCleaner
 
    protected:
 
-   virtual void Erase(const char * /*File*/,std::string /*Pkg*/,std::string /*Ver*/,struct stat & /*St*/) {};
+   APT_DEPRECATED_MSG("Use pkgArchiveCleaner2 to avoid CWD expectations and chdir") virtual void Erase(const char * /*File*/,std::string /*Pkg*/,std::string /*Ver*/,struct stat & /*St*/) {};
 
    public:
 
@@ -34,5 +36,15 @@ class pkgArchiveCleaner
    pkgArchiveCleaner();
    virtual ~pkgArchiveCleaner();
 };
+// TODO: merge classes and "erase" the old way
+class pkgArchiveCleaner2: public pkgArchiveCleaner
+{
+   friend class pkgArchiveCleaner;
+protected:
+   using pkgArchiveCleaner::Erase;
+   virtual void Erase(int const dirfd, char const * const File,
+	 std::string const &Pkg,std::string const &Ver,
+	 struct stat const &St) = 0;
+};
 
 #endif
diff --git a/apt-pkg/contrib/macros.h b/apt-pkg/contrib/macros.h
index bc1f523ea..5e22a195d 100644
--- a/apt-pkg/contrib/macros.h
+++ b/apt-pkg/contrib/macros.h
@@ -165,7 +165,7 @@
 // See also buildlib/libversion.mak
 #define APT_PKG_MAJOR 5
 #define APT_PKG_MINOR 0
-#define APT_PKG_RELEASE 1
+#define APT_PKG_RELEASE 2
 #define APT_PKG_ABI ((APT_PKG_MAJOR * 100) + APT_PKG_MINOR)
 
 #endif