Compare git commit when joining netgames in DEVELOP builds

src/d_clisrv.c

@@ -895,8 +895,15 @@ static void SV_SendServerInfo(INT32 node, tic_t servertime)
 	netbuffer->packettype = PT_SERVERINFO;
 	netbuffer->u.serverinfo._255 = 255;
 	netbuffer->u.serverinfo.packetversion = PACKETVERSION;
+
+#ifdef DEVELOP
+	memcpy(netbuffer->u.serverinfo.commit,
+			comprevision_abbrev_bin, GIT_SHA_ABBREV);
+#else
 	netbuffer->u.serverinfo.version = VERSION;
 	netbuffer->u.serverinfo.subversion = SUBVERSION;
+#endif
+
 	strncpy(netbuffer->u.serverinfo.application, SRB2APPLICATION,
 			sizeof netbuffer->u.serverinfo.application);
 	// return back the time value so client can compute their ping
@@ -1404,11 +1411,13 @@ static void SL_InsertServer(serverinfo_pak* info, SINT8 node)
 		if (info->packetversion != PACKETVERSION)
 			return;/* old new packet format */
 
+#ifndef DEVELOP
 		if (info->version != VERSION)
 			return; // Not same version.
 
 		if (info->subversion != SUBVERSION)
 			return; // Close, but no cigar.
+#endif
 
 		if (strcmp(info->application, SRB2APPLICATION))
 			return;/* that's a different mod */
@@ -1681,6 +1690,35 @@ static boolean CL_ServerConnectionSearchTicker(tic_t *asksent)
 
 		if (client)
 		{
+#ifdef DEVELOP
+			// Commits do not match? Do not connect!
+			if (memcmp(serverlist[i].info.commit,
+						comprevision_abbrev_bin,
+						GIT_SHA_ABBREV))
+			{
+				char theirs[GIT_SHA_ABBREV * 2 + 1];
+				UINT8 n;
+
+				for (n = 0; n < GIT_SHA_ABBREV; ++n)
+				{
+					sprintf(&theirs[n * 2], "%02hhx",
+							serverlist[i].info.commit[n]);
+				}
+
+				D_QuitNetGame();
+				CL_Reset();
+				D_StartTitle();
+
+				M_StartMessage(va(
+							"Your EXE differs from the server.\n"
+							"  Yours: %.*s\n"
+							"Theirs: %s\n\n"
+							"Press ESC\n",
+							GIT_SHA_ABBREV * 2, comprevision, theirs), NULL, MM_NOTHING);
+				return false;
+			}
+#endif
+
 #ifdef HAVE_CURL
 			if (serverlist[i].info.httpsource[0])
 				strncpy(http_source, serverlist[i].info.httpsource, MAX_MIRROR_LENGTH);
@@ -2014,8 +2052,10 @@ static void CL_ConnectToServer(void)
 		gametypestr[sizeof serverlist[i].info.gametypename - 1] = '\0';
 		CON_LogMessage(va(M_GetText("Gametype: %s\n"), gametypestr));
 
+#ifndef DEVELOP
 		CON_LogMessage(va(M_GetText("Version: %d.%d\n"),
 		 serverlist[i].info.version, serverlist[i].info.subversion));
+#endif
 	}
 	SL_ClearServerList(servernode);
 

src/d_clisrv.h

@@ -266,8 +266,12 @@ typedef struct
 	UINT8 _255;
 	UINT8 packetversion;
 	char  application[MAXAPPLICATION];
+#ifdef DEVELOP
+	UINT8 commit[GIT_SHA_ABBREV];
+#else
 	UINT8 version;
 	UINT8 subversion;
+#endif
 	UINT8 numberofplayer;
 	UINT8 maxplayer;
 	UINT8 refusereason; // 0: joinable, 1: joins disabled, 2: full

src/d_main.c

@@ -96,6 +96,10 @@
 int    VERSION;
 int SUBVERSION;
 
+#ifdef DEVELOP
+UINT8 comprevision_abbrev_bin[GIT_SHA_ABBREV];
+#endif
+
 #ifdef HAVE_DISCORDRPC
 #include "discord.h"
 #endif
@@ -1170,6 +1174,20 @@ static void IdentifyVersion(void)
 #endif
 }
 
+#ifdef DEVELOP
+static void
+D_AbbrevCommit (void)
+{
+	UINT8 i;
+
+	for (i = 0; i < GIT_SHA_ABBREV; ++i)
+	{
+		sscanf(&comprevision[i * 2], "%2hhx",
+				&comprevision_abbrev_bin[i]);
+	}
+}
+#endif
+
 static void
 D_ConvertVersionNumbers (void)
 {
@@ -1194,6 +1212,10 @@ void D_SRB2Main(void)
 	/* break the version string into version numbers, for netplay */
 	D_ConvertVersionNumbers();
 
+#ifdef DEVELOP
+	D_AbbrevCommit();
+#endif
+
 	// Print GPL notice for our console users (Linux)
 	CONS_Printf(
 	"\n\nDr. Robotnik's Ring Racers\n"

src/doomdef.h

@@ -516,6 +516,17 @@ char *sizeu5(size_t num);
 // d_main.c
 extern int    VERSION;
 extern int SUBVERSION;
+
+#ifdef DEVELOP
+// 4 bytes handles 8 characters of a git object SHA. At
+// around 20k commits, we only need 6 characters for a unique
+// abbreviation. Maybe in another 20k commits, more than 8
+// characters will be required! =P
+// P.S. 8 is also what comptime generates
+#define GIT_SHA_ABBREV (4)
+extern UINT8 comprevision_abbrev_bin[GIT_SHA_ABBREV];
+#endif
+
 extern boolean devparm; // development mode (-debug)
 // d_netcmd.c
 extern INT32 cv_debug;