From fcafd0784cadde36b21e0a4f36867603d49a88b4 Mon Sep 17 00:00:00 2001
From: Asher Baker <asherkin@limetech.io>
Date: Fri, 19 Jul 2019 09:13:34 +0100
Subject: [PATCH] Workaround CS:GO Stringtable bug (#1046)

The cause of the infamous "Index error writing string table baseline"
error appears to be a timing issue between the engine's network message
processing, the stringtable encoding, and command processing when adding
stringtable entries in OnConfigsExecuted.

When the first client connects the map is re-loaded which causes a full
refresh, the game's stringtable entries are added at tick 65, the client
connection is registered at tick 66, and stringtable entries added in
OnConfigsExecuted are registered as being added in tick 67. The engine
later calls WriteBaselines with the client's signon tick, and neglects
to encode the SM added entries as it considers them from the future.

To avoid this, always pass INT_MAX as the current tick when encoding
the baseline, so all stringtable entries are included regardless of when
they were added. Tested on both Windows and Linux.
---
 extensions/sdktools/extension.cpp       | 27 +++++++++++++++++++++++++
 gamedata/sdktools.games/engine.csgo.txt | 13 ++++++++++++
 2 files changed, 40 insertions(+)

diff --git a/extensions/sdktools/extension.cpp b/extensions/sdktools/extension.cpp
index 695841d5..5c57c5ef 100644
--- a/extensions/sdktools/extension.cpp
+++ b/extensions/sdktools/extension.cpp
@@ -101,6 +101,19 @@ extern sp_nativeinfo_t g_ClientNatives[];
 
 static void InitSDKToolsAPI();
 
+#if SOURCE_ENGINE == SE_CSGO
+CDetour *g_WriteBaselinesDetour = NULL;
+
+DETOUR_DECL_MEMBER3(CNetworkStringTableContainer__WriteBaselines, void, char const *, mapName, void *, buffer, int, currentTick)
+{
+	// Replace nAtTick with INT_MAX to work around CS:GO engine bug.
+	// Due to a timing issue in the engine, stringtable entries added in OnConfigsExecuted can be considered
+	// to have been added in the future for the first client that connects, which causes them to be ignored
+	// when iterating for networking, which triggers a Host_Error encoding the CreateStringTable netmsg.
+	return DETOUR_MEMBER_CALL(CNetworkStringTableContainer__WriteBaselines)(mapName, buffer, INT_MAX);
+}
+#endif
+
 bool SDKTools::SDK_OnLoad(char *error, size_t maxlength, bool late)
 {
 	HandleError err;
@@ -186,6 +199,13 @@ bool SDKTools::SDK_OnLoad(char *error, size_t maxlength, bool late)
 	m_CSGOBadList.init();
 	m_CSGOBadList.add("m_bIsValveDS");
 	m_CSGOBadList.add("m_bIsQuestEligible");
+
+	g_WriteBaselinesDetour = DETOUR_CREATE_MEMBER(CNetworkStringTableContainer__WriteBaselines, "WriteBaselines");
+	if (g_WriteBaselinesDetour) {
+		g_WriteBaselinesDetour->EnableDetour();
+	} else {
+		g_pSM->LogError(myself, "Failed to find WriteBaselines signature -- stringtable error workaround disabled.");
+	}
 #endif
 
 	return true;
@@ -217,6 +237,13 @@ void SDKTools::SDK_OnUnload()
 	g_RegCalls.clear();
 	ShutdownHelpers();
 
+#if SOURCE_ENGINE == SE_CSGO
+	if (g_WriteBaselinesDetour) {
+		g_WriteBaselinesDetour->DisableDetour();
+		g_WriteBaselinesDetour = NULL;
+	}
+#endif
+
 	if (g_pAcceptInput)
 	{
 		g_pAcceptInput->Destroy();
diff --git a/gamedata/sdktools.games/engine.csgo.txt b/gamedata/sdktools.games/engine.csgo.txt
index 56c9d755..1d0de848 100644
--- a/gamedata/sdktools.games/engine.csgo.txt
+++ b/gamedata/sdktools.games/engine.csgo.txt
@@ -348,5 +348,18 @@
 				"mac64"		"279"
 			}
 		}
+		"Signatures"
+		{
+			/**
+			 *	CNetworkStringTableContainer::WriteBaselines
+			 *	"Index error writing string table baseline %s\n"
+			 */
+			"WriteBaselines"
+			{
+				"library"	"engine"
+				"windows"	"\x55\x8B\xEC\x83\xEC\x60\x53\x56\x8B\xF1\x8B\x0D\x2A\x2A\x2A\x2A\x57\x89\x75\xF8\x8B\x81\x2A\x2A\x2A\x2A\x89\x45\xF4\x85\xC0"
+				"linux"		"\x55\x89\xE5\x57\x56\x53\x81\xEC\x8C\x00\x00\x00\x8B\x0D\x2A\x2A\x2A\x2A\x8B\x75\x08\x8B\x5D\x0C\x8B\x7D\x10\x85\xC9"
+			}
+		}
 	}
 }