Lift the 1024-character limit on configuration file lines.

To do this, I changed the configuration parser so that instead of reading
the line into a buffer and munging it in-place, it builds a string
containing the current line (via successive getline() calls) and then
walks down that string.  Instead of skipping comments and whitespace by
erasing them from the buffer, the new code just skips over them.

apt-pkg/contrib/configuration.cc

@@ -495,8 +495,7 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool AsSectional,
    ifstream F(FName.c_str(),ios::in); 
    if (!F != 0)
       return _error->Errno("ifstream::ifstream",_("Opening configuration file %s"),FName.c_str());
-   
-   char Buffer[1024];
+
    string LineBuffer;
    string Stack[100];
    unsigned int StackPos = 0;
@@ -508,24 +507,58 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool AsSectional,
    bool InComment = false;
    while (F.eof() == false)
    {
-      F.getline(Buffer,sizeof(Buffer));
+      // The raw input line.
+      std::string Input;
+      // The input line with comments stripped.
+      std::string Fragment;
+      do
+	{
+	  char *Buffer = new char[1024];
+
+	  F.clear();
+	  F.getline(Buffer,sizeof(Buffer) / 2);
+
+	  Input += Buffer;
+	}
+      while (F.fail() && !F.eof());
+
+      {
+	// Allocate enough space to expand an entire line of tabs
+	// below.
+	const int BufferSize = Input.size() * 8 + 1;
+	char *Buffer = new char[BufferSize];
+	try
+	  {
+	    memcpy(Buffer, Input.c_str(), Input.size() + 1);
+
+	    _strtabexpand(Buffer, BufferSize);
+	    _strstrip(Buffer);
+	    Input = Buffer;
+	  }
+	catch(...)
+	  {
+	    delete[] Buffer;
+	    throw;
+	  }
+	delete[] Buffer;
+      }
       CurLine++;
-      // This should be made to work instead, but this is better than looping
-      if (F.fail() && !F.eof())
-         return _error->Error(_("%s: Line %d too long (max %lu)"),
-			      FName.c_str(), CurLine, sizeof(Buffer));
 
-      _strtabexpand(Buffer,sizeof(Buffer));
-      _strstrip(Buffer);
+      // The first meaningful character in the current fragment; will
+      // be adjusted below as we remove bytes from the front.
+      std::string::const_iterator Start = Input.begin();
+      // The last meaningful character in the current fragment.
+      std::string::const_iterator End = Input.end();
 
       // Multi line comment
       if (InComment == true)
       {
-	 for (const char *I = Buffer; *I != 0; I++)
+	for (std::string::const_iterator I = Start;
+	     I != End; ++I)
 	 {
-	    if (*I == '*' && I[1] == '/')
+	    if (*I == '*' && I + 1 != End && I[1] == '/')
 	    {
-	       memmove(Buffer,I+2,strlen(I+2) + 1);
+	       Start = I + 2;
 	       InComment = false;
 	       break;
 	    }	    
@@ -536,76 +569,94 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool AsSectional,
       
       // Discard single line comments
       bool InQuote = false;
-      for (char *I = Buffer; *I != 0; I++)
+      for (std::string::const_iterator I = Start;
+	   I != End; ++I)
       {
 	 if (*I == '"')
 	    InQuote = !InQuote;
 	 if (InQuote == true)
 	    continue;
 	 
-	 if (*I == '/' && I[1] == '/')
+	 if (*I == '/' && I + 1 != End && I[1] == '/')
          {
-	    *I = 0;
+	    End = I;
 	    break;
 	 }
       }
 
-      // Look for multi line comments
+      // Look for multi line comments and build up the
+      // fragment.
+      Fragment.reserve(End - Start);
       InQuote = false;
-      for (char *I = Buffer; *I != 0; I++)
+      for (std::string::const_iterator I = Start;
+	   I != End; ++I)
       {
 	 if (*I == '"')
 	    InQuote = !InQuote;
 	 if (InQuote == true)
-	    continue;
-	 
-	 if (*I == '/' && I[1] == '*')
+	   Fragment.push_back(*I);
+	 else if (*I == '/' && I + 1 != End && I[1] == '*')
          {
 	    InComment = true;
-	    for (char *J = Buffer; *J != 0; J++)
+	    for (std::string::const_iterator J = I;
+		 J != End; ++J)
 	    {
-	       if (*J == '*' && J[1] == '/')
+	       if (*J == '*' && J + 1 != End && J[1] == '/')
 	       {
-		  memmove(I,J+2,strlen(J+2) + 1);
+		  // Pretend we just finished walking over the
+		  // comment, and don't add anything to the output
+		  // fragment.
+		  I = J + 1;
 		  InComment = false;
 		  break;
 	       }	       
 	    }
 	    
 	    if (InComment == true)
-	    {
-	       *I = 0;
-	       break;
-	    }	    
+	      break;
 	 }
+	 else
+	   Fragment.push_back(*I);
       }
-      
-      // Blank
-      if (Buffer[0] == 0)
+
+      // Skip blank lines.
+      if (Fragment.empty())
 	 continue;
       
-      // We now have a valid line fragment
+      // We now have a valid line fragment.  Walk down it and
+      // interpret it.
       InQuote = false;
-      for (char *I = Buffer; *I != 0;)
+      Start = Fragment.begin();
+      End = Fragment.end();
+      for (std::string::const_iterator I = Start;
+	   I != End; ++I)
       {
+	 if(Start > End)
+	   {
+	     _error->Error("Why is Start > End?");
+	   }
+
 	 if (*I == '"')
 	    InQuote = !InQuote;
 	 
 	 if (InQuote == false && (*I == '{' || *I == ';' || *I == '}'))
 	 {
 	    // Put the last fragment into the buffer
-	    char *Start = Buffer;
-	    char *Stop = I;
-	    for (; Start != I && isspace(*Start) != 0; Start++);
-	    for (; Stop != Start && isspace(Stop[-1]) != 0; Stop--);
-	    if (LineBuffer.empty() == false && Stop - Start != 0)
+	    std::string::const_iterator FirstNonWhitespace = Start;
+	    std::string::const_iterator LastNonWhitespace = I;
+	    for (; FirstNonWhitespace != I && isspace(*FirstNonWhitespace) != 0; FirstNonWhitespace++)
+	      ;
+	    for (; LastNonWhitespace != FirstNonWhitespace && isspace(LastNonWhitespace[-1]) != 0; LastNonWhitespace--)
+	      ;
+	    if (LineBuffer.empty() == false && LastNonWhitespace - FirstNonWhitespace != 0)
 	       LineBuffer += ' ';
-	    LineBuffer += string(Start,Stop - Start);
-	    
-	    // Remove the fragment
+	    LineBuffer += string(FirstNonWhitespace, LastNonWhitespace);
+
+	    // Drop this from the input string, saving the character
+	    // that terminated the construct we just closed. (i.e., a
+	    // brace or a semicolon)
 	    char TermChar = *I;
-	    memmove(Buffer,I + 1,strlen(I + 1) + 1);
-	    I = Buffer;
+	    Start = I + 1;
 	    
 	    // Syntax Error
 	    if (TermChar == '{' && LineBuffer.empty() == true)
@@ -727,15 +778,32 @@ bool ReadConfigFile(Configuration &Conf,const string &FName,bool AsSectional,
 	    }
 	    
 	 }
-	 else
-	    I++;
       }
 
-      // Store the fragment
-      const char *Stripd = _strstrip(Buffer);
-      if (*Stripd != 0 && LineBuffer.empty() == false)
-	 LineBuffer += " ";
-      LineBuffer += Stripd;
+      // Store the remaining text, if any, in the current line buffer.
+
+      // NB: could change this to use string-based operations; I'm
+      // using strstrip now to ensure backwards compatibility.
+      //   -- dburrows 2008-04-01
+      {
+	char *Buffer = new char[End - Start + 1];
+	try
+	  {
+	    std::copy(Start, End, Buffer);
+	    Buffer[End - Start] = '\0';
+
+	    const char *Stripd = _strstrip(Buffer);
+	    if (*Stripd != 0 && LineBuffer.empty() == false)
+	      LineBuffer += " ";
+	    LineBuffer += Stripd;
+	  }
+	catch(...)
+	  {
+	    delete[] Buffer;
+	    throw;
+	  }
+	delete[] Buffer;
+      }
    }
 
    if (LineBuffer.empty() == false)