3 files changed, 57 insertions, 20 deletions

diff --git a/apt-pkg/contrib/configuration.cc b/apt-pkg/contrib/configuration.cc
index 442e31dff..65242bec5 100644
--- a/apt-pkg/contrib/configuration.cc
+++ b/apt-pkg/contrib/configuration.cc
@@ -840,9 +840,9 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectio
 		    unsigned const &Depth)
 {
    // Open the stream for reading
-   ifstream F(FName.c_str(),ios::in);
-   if (F.fail() == true)
-      return _error->Errno("ifstream::ifstream",_("Opening configuration file %s"),FName.c_str());
+   FileFd F;
+   if (OpenConfigurationFileFd(FName, F) == false)
+      return false;
 
    string LineBuffer;
    std::stack<std::string> Stack;
@@ -852,26 +852,15 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool const &AsSectio
 
    int CurLine = 0;
    bool InComment = false;
-   while (F.eof() == false)
+   while (F.Eof() == false)
    {
       // The raw input line.
       std::string Input;
+      if (F.ReadLine(Input) == false)
+	 Input.clear();
       // The input line with comments stripped.
       std::string Fragment;
 
-      // Grab the next line of F and place it in Input.
-      do
-	{
-	  char *Buffer = new char[1024];
-
-	  F.clear();
-	  F.getline(Buffer,sizeof(Buffer) / 2);
-
-	  Input += Buffer;
-	  delete[] Buffer;
-	}
-      while (F.fail() && !F.eof());
-
       // Expand tabs in the input line and remove leading and trailing
       // whitespace.
       {
diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc
index 630a98ce4..7633b07ef 100644
--- a/apt-pkg/contrib/fileutl.cc
+++ b/apt-pkg/contrib/fileutl.cc
@@ -2493,9 +2493,6 @@ bool FileFd::Read(int const Fd, void *To, unsigned long long Size, unsigned long
 }
 									/*}}}*/
 // FileFd::ReadLine - Read a complete line from the file		/*{{{*/
-// ---------------------------------------------------------------------
-/* Beware: This method can be quite slow for big buffers on UNcompressed
-   files because of the naive implementation! */
 char* FileFd::ReadLine(char *To, unsigned long long const Size)
 {
    *To = '\0';
@@ -2503,6 +2500,29 @@ char* FileFd::ReadLine(char *To, unsigned long long const Size)
       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()
@@ -3104,3 +3124,9 @@ bool DropPrivileges()							/*{{{*/
    return true;
 }
 									/*}}}*/
+bool OpenConfigurationFileFd(std::string const &File, FileFd &Fd) /*{{{*/
+{
+   APT::Configuration::Compressor none(".", "", "", nullptr, nullptr, 0);
+   return Fd.Open(File, FileFd::ReadOnly, none);
+}
+									/*}}}*/
diff --git a/apt-pkg/contrib/fileutl.h b/apt-pkg/contrib/fileutl.h
index 5e857b5c8..06c303809 100644
--- a/apt-pkg/contrib/fileutl.h
+++ b/apt-pkg/contrib/fileutl.h
@@ -87,7 +87,28 @@ class FileFd
    }   
    bool Read(void *To,unsigned long long Size,unsigned long long *Actual = 0);
    bool static Read(int const Fd, void *To, unsigned long long Size, unsigned long long * const Actual = 0);
+   /** read a complete line or until buffer is full
+    *
+    * The buffer will always be \\0 terminated, so at most Size-1 characters are read.
+    * If the buffer holds a complete line the last character (before \\0) will be
+    * the newline character \\n otherwise the line was longer than the buffer.
+    *
+    * @param To buffer which will hold the line
+    * @param Size of the buffer to fill
+    * @param \b nullptr is returned in error cases, otherwise
+    * the parameter \b To now filled with the line.
+    */
    char* ReadLine(char *To, unsigned long long const Size);
+   /** read a complete line from the file
+    *
+    *  Similar to std::getline() the string does \b not include
+    *  the newline, but just the content of the line as the newline
+    *  is not needed to distinguish cases as for the other #ReadLine method.
+    *
+    *  @param To string which will hold the line
+    *  @return \b true if successful, otherwise \b false
+    */
+   bool ReadLine(std::string &To);
    bool Flush();
    bool Write(const void *From,unsigned long long Size);
    bool static Write(int Fd, const void *From, unsigned long long Size);
@@ -256,5 +277,6 @@ std::vector<std::string> Glob(std::string const &pattern, int flags=0);
 bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode, bool CaptureStderr);
 bool Popen(const char* Args[], FileFd &Fd, pid_t &Child, FileFd::OpenMode Mode);
 
+APT_HIDDEN bool OpenConfigurationFileFd(std::string const &File, FileFd &Fd);
 
 #endif