Resolve returns in digits

Author: gr8justus

print_digits.c

@@ -19,6 +19,11 @@ int print_decimal(va_list ap)
 	int num = va_arg(ap, int);
 	char *number_string;
 
+	if (!num)
+	{
+		write(2, "Error", 6);
+		return (-1);
+	}
 	if (num < 0)
 	{
 		write(1, "-", 1);

print_helpers.c

@@ -74,6 +74,11 @@ int str_write(char *number_string)
 	size_t i, len, byte_size;
 	int count = 0;
 
+	if (number_string == NULL)
+	{
+		write(2, "Error", 6);
+		return (-1);
+	}
 	len = strlen(number_string);
 	byte_size = ((len - 1) / MAX_BYTE_SIZE) + 1;