From 2f77a98afee2daf6de9a7e2d304e52e15c40510b Mon Sep 17 00:00:00 2001
From: SmileTheory <SmileTheory@gmail.com>
Date: Fri, 25 Sep 2015 04:55:41 -0700
Subject: [PATCH] Use Windows uninstall path to find Steam Quake 3 install.
 Thanks Pan- and Ensiform for pointing this out.

---
 code/qcommon/q_shared.h |  2 ++
 code/sys/sys_win32.c    | 45 +++++++++++++++++++++++++++++++----------
 2 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/code/qcommon/q_shared.h b/code/qcommon/q_shared.h
index 8f82348f..1baa3e1b 100644
--- a/code/qcommon/q_shared.h
+++ b/code/qcommon/q_shared.h
@@ -35,6 +35,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   #define HOMEPATH_NAME_WIN			"FooBar"
   #define HOMEPATH_NAME_MACOSX		HOMEPATH_NAME_WIN
 //  #define STEAMPATH_NAME			"Foo Bar"
+//  #define STEAMPATH_APPID         ""
   #define GAMENAME_FOR_MASTER		"foobar"	// must NOT contain whitespace
 //  #define LEGACY_PROTOCOL	// You probably don't need this for your standalone game
 #else
@@ -46,6 +47,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
   #define HOMEPATH_NAME_WIN			"Quake3"
   #define HOMEPATH_NAME_MACOSX		HOMEPATH_NAME_WIN
   #define STEAMPATH_NAME			"Quake 3 Arena"
+  #define STEAMPATH_APPID			"2200"
   #define GAMENAME_FOR_MASTER		"Quake3Arena"
   #define LEGACY_PROTOCOL
 #endif
diff --git a/code/sys/sys_win32.c b/code/sys/sys_win32.c
index 4c08ef7a..4771e390 100644
--- a/code/sys/sys_win32.c
+++ b/code/sys/sys_win32.c
@@ -136,29 +136,52 @@ Sys_SteamPath
 */
 char *Sys_SteamPath( void )
 {
-#ifdef STEAMPATH_NAME
+#if defined(STEAMPATH_NAME) || defined(STEAMPATH_APPID)
 	HKEY steamRegKey;
+	DWORD pathLen = MAX_OSPATH;
+	qboolean finishPath = qfalse;
+#endif
 
-	if (!RegOpenKeyEx(HKEY_CURRENT_USER, "Software\\Valve\\Steam", 0, KEY_QUERY_VALUE, &steamRegKey))
+#ifdef STEAMPATH_APPID
+	if (!steamPath[0] && !RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\\Wow6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\Steam App " STEAMPATH_APPID, 0, KEY_QUERY_VALUE, &steamRegKey))
 	{
-		DWORD pathLen = MAX_OSPATH;
+		pathLen = MAX_OSPATH;
+		if (RegQueryValueEx(steamRegKey, "InstallLocation", NULL, NULL, (LPBYTE)steamPath, &pathLen))
+			steamPath[0] = '\0';
+	}
 
+	if (!steamPath[0] && !RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall\\Steam App " STEAMPATH_APPID, 0, KEY_QUERY_VALUE, &steamRegKey))
+	{
+		pathLen = MAX_OSPATH;
+		if (RegQueryValueEx(steamRegKey, "InstallLocation", NULL, NULL, (LPBYTE)steamPath, &pathLen))
+			steamPath[0] = '\0';
+	}
+#endif
+
+#ifdef STEAMPATH_NAME
+	if (!steamPath[0] && !RegOpenKeyEx(HKEY_CURRENT_USER, "Software\\Valve\\Steam", 0, KEY_QUERY_VALUE, &steamRegKey))
+	{
+		pathLen = MAX_OSPATH;
 		if (RegQueryValueEx(steamRegKey, "SteamPath", NULL, NULL, (LPBYTE)steamPath, &pathLen))
 			if (RegQueryValueEx(steamRegKey, "InstallPath", NULL, NULL, (LPBYTE)steamPath, &pathLen))
 				steamPath[0] = '\0';
 
 		if (steamPath[0])
-		{
-			if (pathLen == MAX_OSPATH)
-				pathLen--;
-
-			steamPath[pathLen] = '\0';
-
-			Q_strcat(steamPath, MAX_OSPATH, "\\SteamApps\\common\\" STEAMPATH_NAME );
-		}
+			finishPath = qtrue;
 	}
 #endif
 
+	if (steamPath[0])
+	{
+		if (pathLen == MAX_OSPATH)
+			pathLen--;
+
+		steamPath[pathLen] = '\0';
+
+		if (finishPath)
+			Q_strcat(steamPath, MAX_OSPATH, "\\SteamApps\\common\\" STEAMPATH_NAME );
+	}
+
 	return steamPath;
 }