From 4177522e740a174a3e963589849549c075e7a782 Mon Sep 17 00:00:00 2001
From: Daniel Oaks <daniel@danieloaks.net>
Date: Thu, 14 Apr 2016 21:22:17 +1000
Subject: [PATCH] modes: Correct mode argument handling, only first param is
 the modestring

---
 irc/commands.go | 100 +++++++++++++++++++++++++-----------------------
 1 file changed, 53 insertions(+), 47 deletions(-)

diff --git a/irc/commands.go b/irc/commands.go
index dff59a09..ff8a0dcd 100644
--- a/irc/commands.go
+++ b/irc/commands.go
@@ -450,25 +450,29 @@ func ParseUserModeCommand(nickname Name, args []string) (Command, error) {
 		changes:  make(ModeChanges, 0),
 	}
 
-	for _, modeChange := range args {
-		if len(modeChange) == 0 {
+	// account for MODE command with no args to list things
+	if len(args) < 1 {
+		// don't do any further processing
+		return cmd, nil
+	}
+
+	modeArg := args[0]
+	op := ModeOp(modeArg[0])
+	if (op == Add) || (op == Remove) {
+		modeArg = modeArg[1:]
+	} else {
+		return nil, ErrParseCommand
+	}
+
+	for _, mode := range modeArg {
+		if mode == '-' || mode == '+' {
+			op = ModeOp(mode)
 			continue
 		}
-		op := ModeOp(modeChange[0])
-		if (op != Add) && (op != Remove) {
-			return nil, ErrParseCommand
-		}
-
-		for _, mode := range modeChange[1:] {
-			if mode == '-' || mode == '+' {
-				op = ModeOp(mode)
-				continue
-			}
-			cmd.changes = append(cmd.changes, &ModeChange{
-				mode: UserMode(mode),
-				op:   op,
-			})
-		}
+		cmd.changes = append(cmd.changes, &ModeChange{
+			mode: UserMode(mode),
+			op:   op,
+		})
 	}
 
 	return cmd, nil
@@ -531,42 +535,44 @@ func ParseChannelModeCommand(channel Name, args []string) (Command, error) {
 		changes: make(ChannelModeChanges, 0),
 	}
 
-	for len(args) > 0 {
-		if len(args[0]) == 0 {
-			args = args[1:]
+	// account for MODE command with no args to list things
+	if len(args) < 1 {
+		// don't do any further processing
+		return cmd, nil
+	}
+
+	modeArg := args[0]
+	op := ModeOp(modeArg[0])
+	if (op == Add) || (op == Remove) {
+		modeArg = modeArg[1:]
+	} else {
+		return nil, ErrParseCommand
+	}
+
+	currentArgIndex := 1
+
+	for _, mode := range modeArg {
+		if mode == '-' || mode == '+' {
+			op = ModeOp(mode)
 			continue
 		}
-
-		modeArg := args[0]
-		op := ModeOp(modeArg[0])
-		if (op == Add) || (op == Remove) {
-			modeArg = modeArg[1:]
-		} else {
-			op = List
+		change := &ChannelModeChange{
+			mode: ChannelMode(mode),
+			op:   op,
 		}
-
-		skipArgs := 1
-		for _, mode := range modeArg {
-			if mode == '-' || mode == '+' {
-				op = ModeOp(mode)
+		switch change.mode {
+		// TODO(dan): separate this into the type A/B/C/D args and use those lists here
+		case Key, BanMask, ExceptMask, InviteMask, UserLimit,
+			ChannelOperator, ChannelFounder, ChannelAdmin, Halfop, Voice:
+			if len(args) > currentArgIndex {
+				change.arg = args[currentArgIndex]
+				currentArgIndex++
+			} else {
+				// silently skip this mode
 				continue
 			}
-			change := &ChannelModeChange{
-				mode: ChannelMode(mode),
-				op:   op,
-			}
-			switch change.mode {
-			// TODO(dan): separate this into the type A/B/C/D args and use those lists here
-			case Key, BanMask, ExceptMask, InviteMask, UserLimit,
-				ChannelOperator, ChannelFounder, ChannelAdmin, Halfop, Voice:
-				if len(args) > skipArgs {
-					change.arg = args[skipArgs]
-					skipArgs += 1
-				}
-			}
-			cmd.changes = append(cmd.changes, change)
 		}
-		args = args[skipArgs:]
+		cmd.changes = append(cmd.changes, change)
 	}
 
 	return cmd, nil