From af29d7dab238ff074d0cfeb8b51019867f869a17 Mon Sep 17 00:00:00 2001
From: Jason Felds <jafelds@gmail.com>
Date: Wed, 14 Oct 2015 20:23:40 -0400
Subject: [PATCH 1/2] Bring from 5_1_0: don't use insert with RString.

---
 src/RageFileManager.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/RageFileManager.cpp b/src/RageFileManager.cpp
index ba5293245a..7ebe688e65 100644
--- a/src/RageFileManager.cpp
+++ b/src/RageFileManager.cpp
@@ -376,8 +376,14 @@ static void NormalizePath( RString &sPath )
 {
 	FixSlashesInPlace( sPath );
 	CollapsePath( sPath, true );
-	if( sPath.size() == 0 || sPath[0] != '/' )
-		sPath.insert( sPath.begin(), '/' );
+	if (sPath.size() == 0)
+	{
+		sPath = '/';
+	}
+	else if (sPath[0] != '/')
+	{
+		sPath = '/' + sPath;
+	}
 }
 
 bool ilt( const RString &a, const RString &b ) { return a.CompareNoCase(b) < 0; }

From d63881802ae6c096726333d5f37895b702a0b49b Mon Sep 17 00:00:00 2001
From: zardoru <forsakengmex@gmail.com>
Date: Thu, 15 Oct 2015 21:06:23 -0300
Subject: [PATCH 2/2] Make sure kb7 is the appropiate steps type.

---
 src/NotesLoaderBMS.cpp | 52 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 50 insertions(+), 2 deletions(-)

diff --git a/src/NotesLoaderBMS.cpp b/src/NotesLoaderBMS.cpp
index a6cf37615d..492e647680 100644
--- a/src/NotesLoaderBMS.cpp
+++ b/src/NotesLoaderBMS.cpp
@@ -962,8 +962,56 @@ StepsType BMSChartReader::DetermineStepsType()
 					// type, since they are more common.
 					//return StepsType_dance_solo;
 					return StepsType_beat_single5;
-				// az: Allow kb7 style charts
-				case 7:		return StepsType_kb7_single;
+					// az: Allow kb7 style charts
+				case 7:
+				{
+					// az (for nixtrix): kb7 layouts do not leave any gaps using either of these layouts.
+					// if we find a compatible layout that doesn't have gaps, we've stumbled upon a real
+					// kb7 file.
+					BmsRawChannel layoutA[] = {
+						BMS_RAW_P1_TURN,
+						BMS_RAW_P1_KEY1,
+						BMS_RAW_P1_KEY2,
+						BMS_RAW_P1_KEY3,
+						BMS_RAW_P1_KEY4,
+						BMS_RAW_P1_KEY5,
+						BMS_RAW_P1_KEY6,
+					};
+
+					BmsRawChannel layoutB[] = {
+						BMS_RAW_P1_KEY1,
+						BMS_RAW_P1_KEY2,
+						BMS_RAW_P1_KEY3,
+						BMS_RAW_P1_KEY4,
+						BMS_RAW_P1_KEY5,
+						BMS_RAW_P1_KEY6,
+						BMS_RAW_P1_KEY7,
+					};
+
+					int gaps = 0;
+					for (int i = 0; i < 7; i++)
+					{
+						if (nonEmptyTracks.find(layoutA[i]) == nonEmptyTracks.end())
+							gaps++;
+					}
+
+					if (gaps == 0) // kb7 file is a layout A file
+						return StepsType_kb7_single;
+
+					gaps = 0;
+					for (int i = 0; i < 7; i++)
+					{
+						if (nonEmptyTracks.find(layoutB[i]) == nonEmptyTracks.end())
+							gaps++;
+					}
+
+					if (gaps == 0) // kb7 file is a layout B file
+						return StepsType_kb7_single;
+
+					// neither huh, then it's a beatmania file that for some reason
+					// um, chose to not fill in a lane.
+					return StepsType_beat_single7;
+				}
 				case 8:		return StepsType_beat_single7;
 				case 9:		return StepsType_popn_nine;
 				// XXX: Some double files doesn't have #player.