Fixed AddHook() wanting old-style function names.

Error reported by STR_Warrior in the forum http://forum.mc-server.org/showthread.php?tid=1227&pid=9620#pid9620

source/Plugin.h

@@ -113,13 +113,6 @@ public:
 	/// All bound console commands are to be removed, do any language-dependent cleanup here
 	virtual void ClearConsoleCommands(void) {} ;
 	
-	/** Called from cPluginManager::AddHook() to check if the hook can be added.
-	Plugin API providers may check if the plugin is written correctly (has the hook handler function)
-	Returns true if the hook can be added (handler exists)
-	Descendants should also log the specific error message as a warning if they return false.
-	*/
-	virtual bool CanAddHook(int a_Hook) = 0;
-	
 	// tolua_begin
 	const AString & GetName(void) const  { return m_Name; }
 	void SetName(const AString & a_Name) { m_Name = a_Name; }

source/PluginLua.cpp

@@ -1240,13 +1240,16 @@ void cPluginLua::ClearConsoleCommands(void)
 
 
 
-bool cPluginLua::CanAddHook(int a_Hook)
+bool cPluginLua::CanAddOldStyleHook(int a_HookType)
 {
-	const char * FnName = GetHookFnName(a_Hook);
+	const char * FnName = GetHookFnName(a_HookType);
 	if (FnName == NULL)
 	{
 		// Unknown hook ID
-		LOGWARNING("Plugin %s wants to add an unknown hook ID (%d). The plugin need not work properly.", GetName().c_str(), a_Hook);
+		LOGWARNING("Plugin %s wants to add an unknown hook ID (%d). The plugin need not work properly.",
+			GetName().c_str(), a_HookType
+		);
+		m_LuaState.LogStackTrace();
 		return false;
 	}
 	
@@ -1257,12 +1260,9 @@ bool cPluginLua::CanAddHook(int a_Hook)
 	}
 	
 	LOGWARNING("Plugin %s wants to add a hook (%d), but it doesn't provide the callback function \"%s\" for it. The plugin need not work properly.", 
-		GetName().c_str(), a_Hook, FnName
+		GetName().c_str(), a_HookType, FnName
 	);
-	
-	// Lua stacktrace:
 	m_LuaState.LogStackTrace();
-
 	return false;
 }
 
@@ -1270,9 +1270,9 @@ bool cPluginLua::CanAddHook(int a_Hook)
 
 
 
-const char * cPluginLua::GetHookFnName(int a_Hook)
+const char * cPluginLua::GetHookFnName(int a_HookType)
 {
-	switch (a_Hook)
+	switch (a_HookType)
 	{
 		case cPluginManager::HOOK_BLOCK_TO_PICKUPS:             return "OnBlockToPickups";
 		case cPluginManager::HOOK_CHAT:                         return "OnChat";
@@ -1331,7 +1331,17 @@ bool cPluginLua::AddHookRef(int a_HookType, int a_FnRefIdx)
 {
 	ASSERT(m_CriticalSection.IsLockedByCurrentThread());  // It probably has to be, how else would we have a LuaState?
 	
-	m_HookMap[a_HookType].push_back(new cLuaState::cRef(m_LuaState, a_FnRefIdx));
+	// Check if the function reference is valid:
+	cLuaState::cRef * Ref = new cLuaState::cRef(m_LuaState, a_FnRefIdx);
+	if ((Ref == NULL) || !Ref->IsValid())
+	{
+		LOGWARNING("Plugin %s tried to add a hook %d with bad handler function.", GetName().c_str(), a_HookType);
+		m_LuaState.LogStackTrace();
+		delete Ref;
+		return false;
+	}
+	
+	m_HookMap[a_HookType].push_back(Ref);
 	return true;
 }
 

source/PluginLua.h

@@ -100,7 +100,8 @@ public:
 	
 	virtual void ClearConsoleCommands(void) override;
 
-	virtual bool CanAddHook(int a_Hook) override;
+	/// Returns true if the plugin contains the function for the specified hook type, using the old-style registration (#121)
+	bool CanAddOldStyleHook(int a_HookType);
 	
 	// cWebPlugin override
 	virtual const AString GetWebTitle(void) const {return GetName(); }

source/PluginManager.cpp

@@ -1619,10 +1619,6 @@ void cPluginManager::AddHook(cPlugin * a_Plugin, int a_Hook)
 		LOGWARN("Called cPluginManager::AddHook() with a_Plugin == NULL");
 		return;
 	}
-	if (!a_Plugin->CanAddHook(a_Hook))
-	{
-		return;
-	}
 	PluginList & Plugins = m_Hooks[a_Hook];
 	Plugins.remove(a_Plugin);
 	Plugins.push_back(a_Plugin);