skip empty tags, allow = in tag values, better clarify ; split, add IRCv3 tag parsing comment to ParseLine()

client/line.go

@@ -105,6 +105,9 @@ func (line *Line) Public() bool {
 // CTCP command separated from any subsequent text. Then, CTCP ACTIONs are
 // rewritten such that Line.Cmd == ACTION. Other CTCP messages have Cmd
 // set to CTCP or CTCPREPLY, and the CTCP command prepended to line.Args.
+//
+// ParseLine also parses IRCv3 tags, if received. If a line does not have
+// the tags section, Line.Tags will be nil.
 func ParseLine(s string) *Line {
 	line := &Line{Raw: s}
 
@@ -117,19 +120,17 @@ func ParseLine(s string) *Line {
 			return nil
 		}
 
-		// all tags are escaped, so splitting on ; is right by design
+		// ; is represented as \: in a tag, so it's safe to split on ;
 		for _, tag := range strings.Split(rawTags, ";") {
 			if tag == "" {
-				return nil
+				continue
 			}
 
-			pair := strings.Split(tagsReplacer.Replace(tag), "=")
+			pair := strings.SplitN(tagsReplacer.Replace(tag), "=", 2)
 			if len(pair) < 2 {
 				line.Tags[tag] = ""
-			} else if len(pair) == 2 {
-				line.Tags[pair[0]] = pair[1]
 			} else {
-				return nil
+				line.Tags[pair[0]] = pair[1]
 			}
 		}
 	}

client/line_test.go

@@ -137,8 +137,32 @@ func TestLineTags(t *testing.T) {
 				Args:  []string{"me", "Hello"},
 			},
 		},
-		{"@a=a; :nick!ident@host.com PRIVMSG me :Hello", nil}, // Bad inputs
+		{ // Skip empty tag
-		{"@a=a=a :nick!ident@host.com PRIVMSG me :Hello", nil},
+			"@a=a; :nick!ident@host.com PRIVMSG me :Hello",
+			&Line{
+				Tags:  map[string]string{"a": "a"},
+				Nick:  "nick",
+				Ident: "ident",
+				Host:  "host.com",
+				Src:   "nick!ident@host.com",
+				Cmd:   PRIVMSG,
+				Raw:   "@a=a; :nick!ident@host.com PRIVMSG me :Hello",
+				Args:  []string{"me", "Hello"},
+			},
+		},
+		{ // = in tag
+			"@a=a=a; :nick!ident@host.com PRIVMSG me :Hello",
+			&Line{
+				Tags:  map[string]string{"a": "a=a"},
+				Nick:  "nick",
+				Ident: "ident",
+				Host:  "host.com",
+				Src:   "nick!ident@host.com",
+				Cmd:   PRIVMSG,
+				Raw:   "@a=a=a; :nick!ident@host.com PRIVMSG me :Hello",
+				Args:  []string{"me", "Hello"},
+			},
+		},
 	}
 
 	for i, test := range tests {