diff -r 765517f654a5 -r 8856d2e7018d core/CConVarManager.cpp
--- a/core/CConVarManager.cpp	Sun Feb 11 00:17:54 2007 +0000
+++ b/core/CConVarManager.cpp	Sun Feb 11 11:09:38 2007 +0000
@@ -15,43 +15,86 @@
 #include "CLogger.h"
 #include "PluginSys.h"
 #include "sm_srvcmds.h"
+#include "sm_stringutil.h"
 
 CConVarManager g_ConVarManager;
 
-CConVarManager::CConVarManager()
+CConVarManager::CConVarManager() : m_ConVarType(0)
 {
-	m_ConVarType = 0;
-	m_CvarCache = sm_trie_create();
+	// Create a convar lookup trie
+	m_ConVarCache = sm_trie_create();
 }
 
 CConVarManager::~CConVarManager()
 {
-	sm_trie_destroy(m_CvarCache);
+	List<ConVarInfo *>::iterator i;
+
+	// Destroy our convar lookup trie
+	sm_trie_destroy(m_ConVarCache);
+
+	// Destroy all the ConVarInfo structures
+	for (i = m_ConVars.begin(); i != m_ConVars.end(); i++)
+	{
+		delete (*i);
+	}
+
+	m_ConVars.clear();
 }
 
 void CConVarManager::OnSourceModAllInitialized()
 {
 	HandleAccess sec;
 
+	// Set up access rights for the 'ConVar' handle type
 	sec.access[HandleAccess_Read] = 0;
-	sec.access[HandleAccess_Delete] = HANDLE_RESTRICT_IDENTITY|HANDLE_RESTRICT_OWNER;
-	sec.access[HandleAccess_Clone] = HANDLE_RESTRICT_IDENTITY|HANDLE_RESTRICT_OWNER;
+	sec.access[HandleAccess_Delete] = HANDLE_RESTRICT_IDENTITY | HANDLE_RESTRICT_OWNER;
+	sec.access[HandleAccess_Clone] = HANDLE_RESTRICT_IDENTITY | HANDLE_RESTRICT_OWNER;
 
+	// Create the 'ConVar' handle type
 	m_ConVarType = g_HandleSys.CreateType("ConVar", this, 0, NULL, &sec, g_pCoreIdent, NULL);
 
-	g_RootMenu.AddRootConsoleCommand("cvars", "View convars associated with a plugin", this);
+	// Add the 'cvars' option to the 'sm' console command
+	g_RootMenu.AddRootConsoleCommand("cvars", "View convars created by a plugin", this);
 }
 
 void CConVarManager::OnSourceModShutdown()
 {
+	IChangeableForward *fwd;
+	List<ConVarInfo *>::iterator i;
+
+	// Iterate list of ConVarInfo structures
+	for (i = m_ConVars.begin(); i != m_ConVars.end(); i++)
+	{
+		fwd = (*i)->changeForward;
+
+		// Free any convar-change forwards that still exist
+		if (fwd)
+		{
+			g_Forwards.ReleaseForward(fwd);
+		}
+	}
+
+	// Remove the 'cvars' option from the 'sm' console command
 	g_RootMenu.RemoveRootConsoleCommand("cvars", this);
 
+	// Remove the 'ConVar' handle type
 	g_HandleSys.RemoveType(m_ConVarType, g_pCoreIdent);
 }
 
 void CConVarManager::OnHandleDestroy(HandleType_t type, void *object)
 {
-	g_SMAPI->UnregisterConCmdBase(g_PLAPI, static_cast<ConCommandBase *>(object));
+	ConVarInfo *info;
+	ConCommandBase *cvar = static_cast<ConCommandBase *>(object);
+
+	// Find convar in lookup trie
+	sm_trie_retrieve(m_ConVarCache, cvar->GetName(), reinterpret_cast<void **>(&info));
+
+	// If convar was created by SourceMod plugin...
+	if (info->sourceMod)
+	{
+		// Then unregister it
+		g_SMAPI->UnregisterConCmdBase(g_PLAPI, cvar);
+	}
 }
 
 void CConVarManager::OnRootConsoleCommand(const char *command, unsigned int argcount)
@@ -60,15 +103,20 @@
 	{
 		int id = 1;
 
+		// Get plugin index that was passed
 		int num = atoi(g_RootMenu.GetArgument(2));
 		
+		// If invalid plugin index...
 		if (num < 1 || num > (int)g_PluginSys.GetPluginCount())
 		{
 			g_RootMenu.ConsolePrint("[SM] Plugin index not found.");
 			return;
 		}
 
+		// Get plugin object
 		CPlugin *pl = g_PluginSys.GetPluginByOrder(num);
+
+		// Get number of convars created by plugin
 		int convarnum = pl->GetConVarCount();
 
 		if (convarnum == 0)
@@ -79,6 +127,7 @@
 
 		g_RootMenu.ConsolePrint("[SM] Displaying convars for \"%s\":", pl->GetPublicInfo()->name);
 
+		// Iterate convar list and display each one
 		for (int i = 0; i < convarnum; i++, id++)
 		{
 			ConVar *cvar = pl->GetConVarByIndex(i);
@@ -88,13 +137,14 @@
 		return;
 	}
 
+	// Display usage of subcommand
 	g_RootMenu.ConsolePrint("[SM] Usage: sm cvars <#>");
 }
 
 Handle_t CConVarManager::CreateConVar(IPluginContext *pContext, const char *name, const char *defaultVal, const char *helpText, int flags, bool hasMin, float min, bool hasMax, float max)
 {
 	ConVar *cvar = NULL;
-	void *temp = NULL;
+	ConVarInfo *info = NULL;
 	Handle_t hndl = 0;
 
 	// Find out if the convar exists already
@@ -103,33 +153,59 @@
 	// If the convar already exists...
 	if (cvar != NULL)
 	{
-		IPlugin *pl = g_PluginSys.FindPluginByContext(pContext->GetContext());
-
-		// This isn't a fatal error because we can handle it, but user should be warned anyways
-		g_Logger.LogError("[SM] Warning: Plugin \"%s\" has attempted to create already existing convar \"%s\"", pl->GetFilename(), name);
-
 		// First check if we already have a handle to it
-		if (sm_trie_retrieve(m_CvarCache, name, &temp))
+		if (sm_trie_retrieve(m_ConVarCache, name, reinterpret_cast<void **>(&info)))
 		{
 			// If we do, then return that handle
-			return reinterpret_cast<Handle_t>(temp);
+			return info->handle;
 		} else {
-			// If we don't, then create a new handle from the convar and return it
-			return g_HandleSys.CreateHandle(m_ConVarType, cvar, NULL, g_pCoreIdent, NULL);
+			// If we don't, then create a new handle from the convar
+			hndl = g_HandleSys.CreateHandle(m_ConVarType, cvar, NULL, g_pCoreIdent, NULL);
+
+			info = new ConVarInfo;
+			info->handle = hndl;
+			info->sourceMod = false;
+			info->changeForward = NULL;
+			info->origCallback = cvar->GetCallback();
+
+			m_ConVars.push_back(info);
+
+			return hndl;
 		}
 	}
 
-	// Since we didn't find an existing convar, now we can create it
+	// To prevent creating a convar that has the same name as a console command... ugh
+	ConCommandBase *pBase = icvar->GetCommands();
+
+	while (pBase)
+	{
+		if (strcmp(pBase->GetName(), name) == 0)
+		{
+			return pContext->ThrowNativeError("Convar \"%s\" was not created. A console command with the same name already exists.", name);
+		}
+
+		pBase = const_cast<ConCommandBase *>(pBase->GetNext());
+	}
+
+	// Since we didn't find an existing convar (or concmd with the same name), now we can finally create it!
 	cvar = new ConVar(name, defaultVal, flags, helpText, hasMin, min, hasMax, max);
 
 	// Add new convar to plugin's list
 	g_PluginSys.GetPluginByCtx(pContext->GetContext())->AddConVar(cvar);
 
-	// Create a new handle from the convar
+	// Create a handle from the new convar
 	hndl = g_HandleSys.CreateHandle(m_ConVarType, cvar, NULL, g_pCoreIdent, NULL);
 
-	// Insert the handle into our cache
-	sm_trie_insert(m_CvarCache, name, reinterpret_cast<void *>(hndl));
+	info = new ConVarInfo;
+	info->handle = hndl;
+	info->sourceMod = true;
+	info->changeForward = NULL;
+	info->origCallback = NULL;
+
+	m_ConVars.push_back(info);
+
+	// Insert the handle into our lookup trie
+	sm_trie_insert(m_ConVarCache, name, info);
 
 	return hndl;
 }
@@ -137,7 +213,8 @@
 Handle_t CConVarManager::FindConVar(const char *name)
 {
 	ConVar *cvar = NULL;
-	void *temp = NULL;
+	ConVarInfo *info = NULL;
+	Handle_t hndl = 0;
 
 	// Search for convar
 	cvar = icvar->FindVar(name);
@@ -149,12 +226,139 @@
 	}
 
 	// At this point, convar exists, so find out if we already have a handle for it
-	if (sm_trie_retrieve(m_CvarCache, name, &temp))
+	if (sm_trie_retrieve(m_ConVarCache, name, reinterpret_cast<void **>(&info)))
 	{
 		// If we do, then return that handle
-		return reinterpret_cast<Handle_t>(temp);
+		return info->handle;
+	}
+
+	// If we don't, then create a new handle from the convar
+	hndl = g_HandleSys.CreateHandle(m_ConVarType, cvar, NULL, g_pCoreIdent, NULL);
+
+	info = new ConVarInfo;
+	info->handle = hndl;
+	info->sourceMod = false;
+	info->changeForward = NULL;
+	info->origCallback = cvar->GetCallback();
+
+	m_ConVars.push_back(info);
+
+	// Insert the handle into our cache
+	sm_trie_insert(m_ConVarCache, name, info);
+
+	return hndl;
+}
+
+void CConVarManager::HookConVarChange(IPluginContext *pContext, ConVar *cvar, funcid_t funcid)
+{
+	IPluginFunction *func = pContext->GetFunctionById(funcid);
+	IChangeableForward *fwd = NULL;
+	char fwdName[64];
+	ConVarInfo *info = NULL;
+
+	// This shouldn't happen...
+	if (func == NULL)
+	{
+		pContext->ThrowNativeError("Invalid function: %d", funcid);
+		return;
+	}
+
+	// Create a forward name
+	UTIL_Format(fwdName, sizeof(fwdName), "ConVar.%s", cvar->GetName());
+
+	// First find out if the forward already exists
+	g_Forwards.FindForward(fwdName, &fwd);
+
+	// If the forward doesn't exist...
+	if (fwd == NULL)
+	{
+		// This is the forward's parameter type list
+		ParamType p[] = {Param_Cell, Param_String, Param_String};
+
+		// Create the forward
+		fwd = g_Forwards.CreateForwardEx(fwdName, ET_Ignore, 3, p);
+
+		// Find the convar in the lookup trie
+		if (sm_trie_retrieve(m_ConVarCache, cvar->GetName(), reinterpret_cast<void **>(&info)))
+		{
+			// Set the convar's forward to the newly created one
+			info->changeForward = fwd;
+
+			// Set the convar's callback to our static one
+			cvar->InstallChangeCallback(OnConVarChanged);
+		}
 	}
 
-	// If we don't, then create a new handle from the convar and return it
-	return g_HandleSys.CreateHandle(m_ConVarType, cvar, NULL, g_pCoreIdent, NULL);
+	// Add the function to the forward's list
+	fwd->AddFunction(func);
+}
+
+void CConVarManager::UnhookConVarChange(IPluginContext *pContext, ConVar *cvar, funcid_t funcid)
+{
+	IPluginFunction *func = pContext->GetFunctionById(funcid);
+	IChangeableForward *fwd = NULL;
+	ConVarInfo *info = NULL;
+
+	// This shouldn't happen...
+	if (func == NULL)
+	{
+		pContext->ThrowNativeError("Invalid function: %d", funcid);
+		return;
+	}
+
+	// Find the convar in the lookup trie
+	if (sm_trie_retrieve(m_ConVarCache, cvar->GetName(), reinterpret_cast<void **>(&info)))
+	{
+		// Get the forward
+		fwd = info->changeForward;
+
+		// If the forward doesn't exist, we can't unhook anything
+		if (fwd == NULL)
+		{
+			pContext->ThrowNativeError("Convar \"%s\" has no active hook.", cvar->GetName());
+			return;
+		}
+
+		// Remove the function from the forward's list
+		if (!fwd->RemoveFunction(func))
+		{
+			pContext->ThrowNativeError("Function %d is not a valid hook callback for convar \"%s\"", funcid, cvar->GetName());
+			return;
+		}
+
+		// If the forward now has 0 functions in it...
+		if (fwd->GetFunctionCount() == 0)
+		{
+			// Free this forward
+			g_Forwards.ReleaseForward(fwd);
+			info->changeForward = NULL;
+
+			// Put the back the original convar callback
+			cvar->InstallChangeCallback(info->origCallback);
+		}
+	}
+}
+
+void CConVarManager::OnConVarChanged(ConVar *cvar, const char *oldValue)
+{
+	Trie *cache = g_ConVarManager.GetConVarCache();
+	ConVarInfo *info;
+
+	// Find the convar in the lookup trie
+	sm_trie_retrieve(cache, cvar->GetName(), reinterpret_cast<void **>(&info));
+
+	FnChangeCallback origCallback = info->origCallback;
+	IChangeableForward *fwd = info->changeForward;
+
+	// If there was a change callback installed previously, call it
+	if (origCallback)
+	{
+		origCallback(cvar, oldValue);
+	}
+
+	// Now call forwards in plugins that have hooked this
+	fwd->PushCell(info->handle);
+	fwd->PushString(cvar->GetString());
+	fwd->PushString(oldValue);
+	fwd->Execute(NULL);
 }
\ No newline at end of file