doc: fix bad numeric version for irssi, add clientTag test

--HG--
branch : nmdc-ircfrontend

clientTag.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"regexp"
 	"strings"
 )
 
@@ -9,6 +10,10 @@ type clientTag struct {
 	Version string
 }
 
+var (
+	rx_bestNumberPart = regexp.MustCompile(`[0-9\.]+`)
+)
+
 func parseVersion(ver string) clientTag {
 	// Try our best to turn the supplied text into a structured version
 	ret := clientTag{
@@ -39,9 +44,10 @@ func parseVersion(ver string) clientTag {
 		}
 	}
 
-	// Strip leading v from mIRC
+	// We only support digits, periods, and hyphens in the number part
-	if len(ret.Version) >= 2 && (ret.Version[0] == 'v' || ret.Version[0] == 'V') && strings.ContainsAny(string(ret.Version[1]), "0123456789") {
+	// This removes the leading v from mIRC and the trailing deb** from irssi
-		ret.Version = ret.Version[1:]
+	if submatch := rx_bestNumberPart.FindStringSubmatch(ret.Version); len(submatch) == 1 {
+		ret.Version = submatch[0]
 	}
 
 	// Special case: "Relay" means "HoloIRC"

clientTag_test.go

@@ -47,6 +47,11 @@ func TestParseVersion(t *testing.T) {
 			"Revolution IRC:0.3.2:Android",
 			"Revolution IRC", "0.3.2",
 		},
+
+		[3]string{
+			"irssi v1.0.2-1+deb9u3",
+			"irssi", "1.0.2",
+		},
 	}
 
 	for _, test := range tests {