validate correctness of song formats at start

src/settings.cpp

@@ -24,6 +24,7 @@
 # include <sys/stat.h>
 #endif // WIN32
 #include <fstream>
+#include <stdexcept>
 
 #include "global.h"
 #include "helpers.h"
@@ -61,6 +62,20 @@ namespace
 		key[1] = !two.empty() && two[0] == '\'' ? two[1] : (atoi(two.c_str()) == 0 ? null_key : atoi(two.c_str()));
 	}
 	
+	void ValidateSongFormat(const std::string &type, const std::string &s)
+	{
+		int braces = 0;
+		for (std::string::const_iterator it = s.begin(); it != s.end(); ++it)
+		{
+			if (*it == '{')
+				++braces;
+			else if (*it == '}')
+				--braces;
+		}
+		if (braces)
+			throw std::runtime_error(type + ": number of opening and closing braces does not equal!");
+	}
+	
 	Border IntoBorder(const std::string &color)
 	{
 		return Border(IntoColor(color));
@@ -522,7 +537,12 @@ void ReadConfiguration(ncmpcpp_config &conf)
 			else if (cl.find("song_list_format") != std::string::npos)
 			{
 				if (!v.empty())
-					conf.song_list_format = v;
+				{
+					ValidateSongFormat("song_list_format", v);
+					conf.song_list_format = '{';
+					conf.song_list_format += v;
+					conf.song_list_format += '}';
+				}
 			}
 			else if (cl.find("song_columns_list_format") != std::string::npos)
 			{
@@ -532,17 +552,32 @@ void ReadConfiguration(ncmpcpp_config &conf)
 			else if (cl.find("song_status_format") != std::string::npos)
 			{
 				if (!v.empty())
-					conf.song_status_format = v;
+				{
+					ValidateSongFormat("song_status_format", v);
+					conf.song_status_format = '{';
+					conf.song_status_format += v;
+					conf.song_status_format += '}';
+				}
 			}
 			else if (cl.find("song_library_format") != std::string::npos)
 			{
 				if (!v.empty())
-					conf.song_library_format = v;
+				{
+					ValidateSongFormat("song_library_format", v);
+					conf.song_library_format = '{';
+					conf.song_library_format += v;
+					conf.song_library_format += '}';
+				}
 			}
 			else if (cl.find("tag_editor_album_format") != std::string::npos)
 			{
 				if (!v.empty())
-					conf.tag_editor_album_format = v;
+				{
+					ValidateSongFormat("tag_editor_album_format", v);
+					conf.tag_editor_album_format = '{';
+					conf.tag_editor_album_format += v;
+					conf.tag_editor_album_format += '}';
+				}
 			}
 			else if (cl.find("external_editor") != std::string::npos)
 			{
@@ -562,12 +597,22 @@ void ReadConfiguration(ncmpcpp_config &conf)
 			else if (cl.find("alternative_header_first_line_format") != std::string::npos)
 			{
 				if (!v.empty())
-					conf.new_header_first_line = v;
+				{
+					ValidateSongFormat("alternative_header_first_line_format", v);
+					conf.new_header_first_line = '{';
+					conf.new_header_first_line += v;
+					conf.new_header_first_line += '}';
+				}
 			}
 			else if (cl.find("alternative_header_second_line_format") != std::string::npos)
 			{
 				if (!v.empty())
-					conf.new_header_second_line = v;
+				{
+					ValidateSongFormat("alternative_header_second_line_format", v);
+					conf.new_header_second_line = '{';
+					conf.new_header_second_line += v;
+					conf.new_header_second_line += '}';
+				}
 			}
 			else if (cl.find("browser_playlist_prefix") != std::string::npos)
 			{
@@ -744,7 +789,12 @@ void ReadConfiguration(ncmpcpp_config &conf)
 			else if (cl.find("song_window_title_format") != std::string::npos)
 			{
 				if (!v.empty())
-					conf.song_window_title_format = v;
+				{
+					ValidateSongFormat("song_window_title_format", v);
+					conf.song_window_title_format = '{';
+					conf.song_window_title_format += v;
+					conf.song_window_title_format += '}';
+				}
 			}
 			else if (cl.find("empty_tag") != std::string::npos)
 			{