From 93c1f2a9dd8fa423d0c7f3d57f12e68ad6fdcbd5 Mon Sep 17 00:00:00 2001
From: nosoop <nosoop@users.noreply.github.com>
Date: Sun, 17 Mar 2019 05:02:25 -0700
Subject: [PATCH] Add KV key existence check

Bandaid that fixes #1.
---
 gamedata/tf2.econ_data.txt |  7 +++++++
 scripting/tf_econ_data.sp  | 17 ++++++++++++++++-
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/gamedata/tf2.econ_data.txt b/gamedata/tf2.econ_data.txt
index 45d0ac5..fc8b3f6 100644
--- a/gamedata/tf2.econ_data.txt
+++ b/gamedata/tf2.econ_data.txt
@@ -31,6 +31,13 @@
 				"linux"		"@_ZN9KeyValues9GetStringEPKcS1_"
 				"windows"	"\x55\x8B\xEC\x81\xEC\x40\x02\x00\x00"
 			}
+			"KeyValues::FindKey()"
+			{
+				// first call in KeyValues::GetString()
+				"library"	"server"
+				"linux"		"@_ZN9KeyValues7FindKeyEPKcb"
+				"windows"	"\x55\x8B\xEC\x81\xEC\x04\x01\x00\x00\x56\x8B\x75\x08\x57"
+			}
 		}
 		
 		"Offsets"
diff --git a/scripting/tf_econ_data.sp b/scripting/tf_econ_data.sp
index 30fa2b0..aa42da6 100644
--- a/scripting/tf_econ_data.sp
+++ b/scripting/tf_econ_data.sp
@@ -26,6 +26,7 @@ Handle g_SDKCallGetEconItemSchema;
 Handle g_SDKCallSchemaGetItemDefinition;
 Handle g_SDKCallTranslateWeaponEntForClass;
 Handle g_SDKCallGetKeyValuesString;
+Handle g_SDKCallGetKeyValuesFindKey;
 
 Address offs_CEconItemDefinition_pKeyValues,
 		offs_CEconItemDefinition_u8MinLevel,
@@ -94,6 +95,13 @@ public void OnPluginStart() {
 	PrepSDKCall_AddParameter(SDKType_PlainOldData, SDKPass_Plain);
 	g_SDKCallGetKeyValuesString = EndPrepSDKCall();
 	
+	StartPrepSDKCall(SDKCall_Raw);
+	PrepSDKCall_SetFromConf(hGameConf, SDKConf_Signature, "KeyValues::FindKey()");
+	PrepSDKCall_SetReturnInfo(SDKType_PlainOldData, SDKPass_Plain);
+	PrepSDKCall_AddParameter(SDKType_String, SDKPass_Pointer);
+	PrepSDKCall_AddParameter(SDKType_Bool, SDKPass_Plain);
+	g_SDKCallGetKeyValuesFindKey = EndPrepSDKCall();
+	
 	offs_CEconItemDefinition_pKeyValues =
 			GameConfGetAddressOffset(hGameConf, "CEconItemDefinition::m_pKeyValues");
 	offs_CEconItemDefinition_u8MinLevel =
@@ -222,7 +230,7 @@ public int Native_GetItemDefinitionString(Handle hPlugin, int nParams) {
 	Address pItemDef = GetEconItemDefinition(defindex);
 	if (pItemDef) {
 		Address pKeyValues = DereferencePointer(pItemDef + offs_CEconItemDefinition_pKeyValues);
-		if (pKeyValues) {
+		if (KeyValuesPtrKeyExists(pKeyValues, key)) {
 			SDKCall(g_SDKCallGetKeyValuesString, pKeyValues, buffer, maxlen, key, buffer);
 		}
 	}
@@ -320,6 +328,13 @@ static bool LoadEconItemDefinitionString(int defindex, Address offset, char[] bu
 	return true;
 }
 
+static bool KeyValuesPtrKeyExists(Address pKeyValues, const char[] key) {
+	if (!pKeyValues) {
+		return false;
+	}
+	return !!SDKCall(g_SDKCallGetKeyValuesFindKey, pKeyValues, key, false);
+}
+
 static Address GetEconItemSchema() {
 	return SDKCall(g_SDKCallGetEconItemSchema);
 }