From feb18208cbb6fbe0c380d96713af2278aa4119cb Mon Sep 17 00:00:00 2001
From: fickleheart <fickle@tinted.red>
Date: Sat, 21 Mar 2020 01:36:39 -0500
Subject: [PATCH] Add support for srb2:// URL handler (server links)

---
 src/d_main.c | 27 +++++++++++++++++++++++++--
 src/i_tcp.c  |  9 ++++++---
 src/m_argv.c | 18 ++++++++++++++++++
 src/m_argv.h |  3 +++
 4 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/src/d_main.c b/src/d_main.c
index 3840e77a0..d954fa4d1 100644
--- a/src/d_main.c
+++ b/src/d_main.c
@@ -889,6 +889,29 @@ static void IdentifyVersion(void)
 	char *srb2wad;
 	const char *srb2waddir = NULL;
 
+	// URL handlers are opened by web browsers (at least Firefox) from the browser's working directory, not the game's stored directory,
+	// so chdir to that directory unless overridden.
+	if (M_GetUrlProtocolArg() != NULL && !M_CheckParm("-nochdir"))
+	{
+		size_t i;
+
+		CONS_Printf("srb2:// connect links load game files from the SRB2 application's stored directory. Switching to ");
+		strlcpy(srb2path, myargv[0], sizeof(srb2path));
+
+		// Get just the directory, minus the EXE name
+		for (i = strlen(srb2path)-1; i > 0; i--)
+		{
+			if (srb2path[i] == '/' || srb2path[i] == '\\')
+			{
+				srb2path[i] = '\0';
+				break;
+			}
+		}
+
+		CONS_Printf("%s\n", srb2path);
+		chdir(srb2path);
+	}
+
 #if (defined (__unix__) && !defined (MSDOS)) || defined (UNIXCOMMON) || defined (HAVE_SDL)
 	// change to the directory where 'srb2.pk3' is found
 	srb2waddir = I_LocateWad();
@@ -1152,7 +1175,7 @@ void D_SRB2Main(void)
 
 	// add any files specified on the command line with -file wadfile
 	// to the wad list
-	if (!(M_CheckParm("-connect") && !M_CheckParm("-server")))
+	if (!((M_GetUrlProtocolArg() || M_CheckParm("-connect")) && !M_CheckParm("-server")))
 	{
 		if (M_CheckParm("-file"))
 		{
@@ -1187,7 +1210,7 @@ void D_SRB2Main(void)
 	M_InitMenuPresTables();
 
 	// init title screen display params
-	if (M_CheckParm("-connect"))
+	if (M_GetUrlProtocolArg() || M_CheckParm("-connect"))
 		F_InitMenuPresValues();
 
 	//---------------------------------------------------- READY TIME
diff --git a/src/i_tcp.c b/src/i_tcp.c
index 34cad1765..373ea1bd0 100644
--- a/src/i_tcp.c
+++ b/src/i_tcp.c
@@ -1423,6 +1423,7 @@ static void SOCK_ClearBans(void)
 boolean I_InitTcpNetwork(void)
 {
 	char serverhostname[255];
+	const char *urlparam = NULL;
 	boolean ret = false;
 	// initilize the OS's TCP/IP stack
 	if (!I_InitTcpDriver())
@@ -1476,10 +1477,12 @@ boolean I_InitTcpNetwork(void)
 
 		ret = true;
 	}
-	else if (M_CheckParm("-connect"))
+	else if ((urlparam = M_GetUrlProtocolArg()) != NULL || M_CheckParm("-connect"))
 	{
-		if (M_IsNextParm())
-			strcpy(serverhostname, M_GetNextParm());
+		if (urlparam != NULL)
+			strlcpy(serverhostname, urlparam, sizeof(serverhostname));
+		else if (M_IsNextParm())
+			strlcpy(serverhostname, M_GetNextParm(), sizeof(serverhostname));
 		else
 			serverhostname[0] = 0; // assuming server in the LAN, use broadcast to detect it
 
diff --git a/src/m_argv.c b/src/m_argv.c
index acb74cff4..d7d1f4463 100644
--- a/src/m_argv.c
+++ b/src/m_argv.c
@@ -34,6 +34,24 @@ boolean myargmalloc = false;
 */
 static INT32 found;
 
+/**	\brief Parses a server URL (such as srb2://127.0.0.1) as may be passed to the game via a web browser, etc.
+
+	\return the contents of the URL after the protocol (a server to join), or NULL if not found
+*/
+const char *M_GetUrlProtocolArg(void)
+{
+	INT32 i;
+
+	for (i = 1; i < myargc; i++)
+	{
+		if (!strnicmp(myargv[i], "srb2://", 7))
+		{
+			return &myargv[i][7];
+		}
+	}
+
+	return NULL;
+}
 
 /**	\brief	The M_CheckParm function
 
diff --git a/src/m_argv.h b/src/m_argv.h
index ca97d9b12..92770f4e9 100644
--- a/src/m_argv.h
+++ b/src/m_argv.h
@@ -21,6 +21,9 @@ extern INT32 myargc;
 extern char **myargv;
 extern boolean myargmalloc;
 
+// Looks for an srb2:// (or similar) URL passed in as an argument and returns the IP to connect to if found.
+const char *M_GetUrlProtocolArg(void);
+
 // Returns the position of the given parameter in the arg list (0 if not found).
 INT32 M_CheckParm(const char *check);