Fix:(issue_1731) Add fix for checking if aliases are set

context.go

@@ -56,6 +56,7 @@ func (cCtx *Context) Set(name, value string) error {
 
 // IsSet determines if the flag was actually set
 func (cCtx *Context) IsSet(name string) bool {
+
 	if fs := cCtx.lookupFlagSet(name); fs != nil {
 		isSet := false
 		fs.Visit(func(f *flag.Flag) {
@@ -72,7 +73,23 @@ func (cCtx *Context) IsSet(name string) bool {
 			return false
 		}
 
-		return f.IsSet()
+		if f.IsSet() {
+			return true
+		}
+
+		// now redo flagset search on aliases
+		aliases := f.Names()
+		fs.Visit(func(f *flag.Flag) {
+			for _, alias := range aliases {
+				if f.Name == alias {
+					isSet = true
+				}
+			}
+		})
+
+		if isSet {
+			return true
+		}
 	}
 
 	return false

context_test.go

@@ -212,6 +212,39 @@ func TestContext_IsSet(t *testing.T) {
 	expect(t, ctx.IsSet("bogus"), false)
 }
 
+func TestContext_IsSet_Aliases(t *testing.T) {
+
+	var fooSet, fSet, tSet, iglooSet bool
+
+	a := App{
+		Flags: []Flag{
+			&Int64Flag{
+				Name:    "foo",
+				Aliases: []string{"f", "t", "igloo"},
+			},
+		},
+		Action: func(ctx *Context) error {
+			fooSet = ctx.IsSet("foo")
+			fSet = ctx.IsSet("f")
+			tSet = ctx.IsSet("t")
+			iglooSet = ctx.IsSet("igloo")
+			return nil
+		},
+	}
+
+	_ = a.Run([]string{"run"})
+	expect(t, fooSet, false)
+	expect(t, fSet, false)
+	expect(t, tSet, false)
+	expect(t, iglooSet, false)
+
+	_ = a.Run([]string{"run", "--t", "10"})
+	expect(t, fooSet, true)
+	expect(t, fSet, true)
+	expect(t, tSet, true)
+	expect(t, iglooSet, true)
+}
+
 // XXX Corresponds to hack in context.IsSet for flags with EnvVar field
 // Should be moved to `flag_test` in v2
 func TestContext_IsSet_fromEnv(t *testing.T) {