Fix not sending ERR_INVALIDMODEPARAM when a parameter is malformed.

Closes #1850.

2 files changed, 21 insertions, 0 deletions

diff --git a/include/mode.h b/include/mode.h
index 97222bf78..236e1b035 100644
--- a/include/mode.h
+++ b/include/mode.h
@@ -274,6 +274,7 @@ class CoreExport ModeHandler : public ServiceProvider
 	 * @return MODEACTION_ALLOW to allow the mode, or MODEACTION_DENY to prevent the mode, also see the description of 'parameter'.
 	 */
 	virtual ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string &parameter, bool adding); /* Can change the mode parameter as its a ref */
+
 	/**
 	 * If your mode is a listmode, then this method will be called for displaying an item list, e.g. on MODE \#channel +modechar
 	 * without any parameter or other modes in the command.
@@ -290,6 +291,15 @@ class CoreExport ModeHandler : public ServiceProvider
 	 */
 	virtual void OnParameterMissing(User* user, User* dest, Channel* channel);
 
+	/** Called when a user attempts to set a mode and the parameter is invalid.
+	 * @param user The user issuing the mode change
+	 * @param targetchannel Either the channel target or NULL if changing a user mode.
+	 * @param targetuser Either the user target or NULL if changing a channel mode.
+	 * @param parameter The invalid parameter.
+	 */
+	virtual void OnParameterInvalid(User* user, Channel* targetchannel, User* targetuser, const std::string& parameter);
+
+
 	/**
 	 * If your mode is a listmode, this method will be called to display an empty list (just the end of list numeric)
 	 * @param user The user issuing the command
diff --git a/src/mode.cpp b/src/mode.cpp
index 1c17a6598..d183d0240 100644
--- a/src/mode.cpp
+++ b/src/mode.cpp
@@ -104,6 +104,14 @@ void ModeHandler::OnParameterMissing(User* user, User* dest, Channel* channel)
 		user->WriteNumeric(Numerics::InvalidModeParameter(dest, this, "*", message));
 }
 
+void ModeHandler::OnParameterInvalid(User* user, Channel* targetchannel, User* targetuser, const std::string& parameter)
+{
+	if (targetchannel)
+		user->WriteNumeric(Numerics::InvalidModeParameter(targetchannel, this, "*"));
+	else
+		user->WriteNumeric(Numerics::InvalidModeParameter(targetuser, this, "*"));
+}
+
 bool ModeHandler::ResolveModeConflict(std::string& theirs, const std::string& ours, Channel*)
 {
 	return (theirs < ours);
@@ -403,7 +411,10 @@ static bool IsModeParamValid(User* user, Channel* targetchannel, User* targetuse
 
 	// The parameter cannot begin with a ':' character or contain a space
 	if ((item.param[0] == ':') || (item.param.find(' ') != std::string::npos))
+	{
+		item.mh->OnParameterInvalid(user, targetchannel, targetuser, item.param);
 		return false;
+	}
 
 	return true;
 }