client/systray: don't repeat account name for single-user tailnets (#19930)

Single-user tailnets often have the same tailnet display name as login
name.

This change omits the duplication when matching, and skips the
user-switching submenu when only one account is configured, to clean up
the account display a little bit.

Fixes #16889

Signed-off-by: Evan Lowry <evan@tailscale.com>

client/systray/systray.go

@@ -292,21 +292,23 @@ func (menu *Menu) rebuild() {
 		accounts := systray.AddMenuItem(account, "")
 		setRemoteIcon(accounts, menu.curProfile.UserProfile.ProfilePicURL)
 		time.Sleep(newMenuDelay)
-		for _, profile := range menu.allProfiles {
-			title := profileTitle(profile)
-			var item *systray.MenuItem
-			if profile.ID == menu.curProfile.ID {
-				item = accounts.AddSubMenuItemCheckbox(title, "", true)
-			} else {
-				item = accounts.AddSubMenuItem(title, "")
-			}
-			setRemoteIcon(item, profile.UserProfile.ProfilePicURL)
-			onClick(ctx, item, func(ctx context.Context) {
-				select {
-				case <-ctx.Done():
-				case menu.accountsCh <- profile.ID:
+		if len(menu.allProfiles) > 1 {
+			for _, profile := range menu.allProfiles {
+				title := profileTitle(profile)
+				var item *systray.MenuItem
+				if profile.ID == menu.curProfile.ID {
+					item = accounts.AddSubMenuItemCheckbox(title, "", true)
+				} else {
+					item = accounts.AddSubMenuItem(title, "")
 				}
-			})
+				setRemoteIcon(item, profile.UserProfile.ProfilePicURL)
+				onClick(ctx, item, func(ctx context.Context) {
+					select {
+					case <-ctx.Done():
+					case menu.accountsCh <- profile.ID:
+					}
+				})
+			}
 		}
 	}
 
@@ -352,16 +354,27 @@ func (menu *Menu) rebuild() {
 
 // profileTitle returns the title string for a profile menu item.
 func profileTitle(profile ipn.LoginProfile) string {
-	title := profile.Name
+	tailnet := ""
 	if profile.NetworkProfile.DomainName != "" {
-		if runtime.GOOS == "windows" || runtime.GOOS == "darwin" {
-			// windows and mac don't support multi-line menu
-			title += " (" + profile.NetworkProfile.DisplayNameOrDefault() + ")"
-		} else {
-			title += "\n" + profile.NetworkProfile.DisplayNameOrDefault()
-		}
+		tailnet = profile.NetworkProfile.DisplayNameOrDefault()
 	}
-	return title
+	// windows and mac don't support multi-line menu items.
+	multiline := runtime.GOOS != "windows" && runtime.GOOS != "darwin"
+
+	return formatProfileTitle(profile.Name, tailnet, multiline)
+}
+
+// formatProfileTitle builds a profile menu label from a login name and an
+// optional tailnet name. The tailnet portion is omitted when it matches the
+// login name, so single-user tailnets don't show the same string twice.
+func formatProfileTitle(name, tailnet string, multiline bool) string {
+	if tailnet == "" || strings.EqualFold(name, tailnet) {
+		return name
+	}
+	if multiline {
+		return name + "\n" + tailnet
+	}
+	return name + " (" + tailnet + ")"
 }
 
 var (

client/systray/systray_test.go

@@ -13,6 +13,33 @@ import (
 	"tailscale.com/types/key"
 )
 
+func TestProfileTitleMultiline(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name      string
+		login     string
+		tailnet   string
+		multiline bool
+		want      string
+	}{
+		{"no_tailnet", "alice@example.com", "", true, "alice@example.com"},
+		{"dup_exact", "example.com", "example.com", true, "example.com"},
+		{"dup_casefold", "Example.com", "example.com", false, "Example.com"},
+		{"distinct_multiline", "alice@example.com", "example.com", true, "alice@example.com\nexample.com"},
+		{"distinct_singleline", "alice@example.com", "example.com", false, "alice@example.com (example.com)"},
+		{"empty", "", "", true, ""},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			if got := formatProfileTitle(tt.login, tt.tailnet, tt.multiline); got != tt.want {
+				t.Errorf("profileTitleMultiline; got %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
 func TestRecommendedIsActive(t *testing.T) {
 	t.Parallel()