fix: RGBFromString() maybe input overflow int value

Author: inhere

color_rgb.go

@@ -156,17 +156,17 @@ func RGBFromString(rgb string, isBg ...bool) RGBColor {
 		return emptyRGBColor
 	}
 
-	var ar [3]int
+	var ar [3]uint8
 	for i, val := range ss {
 		iv, err := strconv.Atoi(val)
-		if err != nil {
+		if err != nil || !isValidUint8(iv) {
 			return emptyRGBColor
 		}
 
-		ar[i] = iv
+		ar[i] = uint8(iv)
 	}
 
-	return RGB(uint8(ar[0]), uint8(ar[1]), uint8(ar[2]), isBg...)
+	return RGB(ar[0], ar[1], ar[2], isBg...)
 }
 
 // Set terminal by rgb/true color code

color_rgb_test.go

@@ -98,6 +98,9 @@ func TestRGBFromString(t *testing.T) {
 
 	c = RGBFromString("170,187,error")
 	is.Equal("msg", c.Sprint("msg"))
+
+	c = RGBFromString("170,-187,-34")
+	is.Equal("msg", c.Sprint("msg"))
 }
 
 func TestHexToRGB(t *testing.T) {

utils.go

@@ -184,6 +184,11 @@ func debugf(f string, v ...interface{}) {
 	}
 }
 
+// equals: return ok ? val1 : val2
+func isValidUint8(val int) bool {
+	return val >= 0 && val < 256
+}
+
 // equals: return ok ? val1 : val2
 func compareVal(ok bool, val1, val2 uint8) uint8 {
 	if ok {