updated dependencies

vendor/github.com/urfave/cli/flag_string_slice.go

@@ -17,7 +17,7 @@ func (f *StringSlice) Set(value string) error {
 
 // String returns a readable representation of this value (for usage defaults)
 func (f *StringSlice) String() string {
-	return fmt.Sprintf("%s", *f)
+	return strings.Join(*f, ",")
 }
 
 // Value returns the slice of strings set by this flag
@@ -128,11 +128,55 @@ func (c *Context) GlobalStringSlice(name string) []string {
 func lookupStringSlice(name string, set *flag.FlagSet) []string {
 	f := set.Lookup(name)
 	if f != nil {
-		parsed, err := (f.Value.(*StringSlice)).Value(), error(nil)
-		if err != nil {
+		value, ok := f.Value.(*StringSlice)
+		if !ok {
 			return nil
 		}
-		return parsed
+		// extract the slice from asserted value
+		slice := value.Value()
+
+		// extract default value from the flag
+		var defaultVal []string
+		for _, v := range strings.Split(f.DefValue, ",") {
+			defaultVal = append(defaultVal, v)
+		}
+
+		// if the current value is not equal to the default value
+		// remove the default values from the flag
+		if !isStringSliceEqual(slice, defaultVal) {
+			for _, v := range defaultVal {
+				slice = removeFromStringSlice(slice, v)
+			}
+		}
+		return slice
 	}
 	return nil
 }
+
+func removeFromStringSlice(slice []string, val string) []string {
+	for i, v := range slice {
+		if v == val {
+			return append(slice[:i], slice[i+1:]...)
+		}
+	}
+	return slice
+}
+
+func isStringSliceEqual(newValue, defaultValue []string) bool {
+	// If one is nil, the other must also be nil.
+	if (newValue == nil) != (defaultValue == nil) {
+		return false
+	}
+
+	if len(newValue) != len(defaultValue) {
+		return false
+	}
+
+	for i, v := range newValue {
+		if v != defaultValue[i] {
+			return false
+		}
+	}
+
+	return true
+}