Convert tabs to spaces internally before parsing MML, fix #3

src/song_manager.cpp

@@ -412,7 +412,7 @@ void Song_Manager::compile_job(std::unique_lock<std::mutex>& lock, std::string b
 		std::stringstream stream(buffer);
 		for(; std::getline(stream, str);)
 		{
-			input.read_line(str, line);
+			input.read_line(tabs_to_spaces(str), line);
 			temp_lines.get()->insert({line, input.get_track_map()});
 			line++;
 		}
@@ -450,3 +450,29 @@ void Song_Manager::compile_job(std::unique_lock<std::mutex>& lock, std::string b
 	error_reference = ref;
 }
 
+//! Convert all tabs to spaces in a string.
+/*!
+ *  Currently tabstop is hardcoded to 4 to match the editor.
+ */
+std::string Song_Manager::tabs_to_spaces(const std::string& str) const
+{
+	const unsigned int tabstop = 4;
+	std::string out = "";
+	for(char i : str)
+	{
+		if(i == '\t')
+		{
+			do
+			{
+				out.push_back(' ');
+			}
+			while(out.size() % tabstop != 0);
+		}
+		else
+		{
+			out.push_back(i);
+		}
+	}
+	return out;
+}
+

src/song_manager.h

@@ -74,6 +74,7 @@ class Song_Manager
 	private:
 		void worker();
 		void compile_job(std::unique_lock<std::mutex>& lock, std::string buffer, std::string filename);
+		std::string tabs_to_spaces(const std::string& str) const;
 
 		// song status
 		const static int max_channels;