1 files changed, 43 insertions, 0 deletions
diff --git a/common/util.cpp b/common/util.cpp
index 1c4df8b6cd..3f97308d8e 100644
--- a/common/util.cpp
+++ b/common/util.cpp
@@ -19,6 +19,15 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
+#define FORBIDDEN_SYMBOL_EXCEPTION_isalnum
+#define FORBIDDEN_SYMBOL_EXCEPTION_isalpha
+#define FORBIDDEN_SYMBOL_EXCEPTION_isdigit
+#define FORBIDDEN_SYMBOL_EXCEPTION_isnumber
+#define FORBIDDEN_SYMBOL_EXCEPTION_islower
+#define FORBIDDEN_SYMBOL_EXCEPTION_isspace
+#define FORBIDDEN_SYMBOL_EXCEPTION_isupper
+
+
 #include "common/util.h"
 #include "common/translation.h"
 #include "common/config-manager.h"
@@ -406,4 +415,38 @@ void updateGameGUIOptions(const String &options, const String &langOption) {
 	}
 }
 
+#define ENSURE_ASCII_CHAR(c) \
+		if (c < 0 || c > 127) \
+			return false
+
+bool isAlnum(int c) {
+	ENSURE_ASCII_CHAR(c);
+	return isalnum((byte)c);
+}
+
+bool isAlpha(int c) {
+	ENSURE_ASCII_CHAR(c);
+	return isalpha((byte)c);
+}
+
+bool isDigit(int c) {
+	ENSURE_ASCII_CHAR(c);
+	return isdigit((byte)c);
+}
+
+bool isLower(int c) {
+	ENSURE_ASCII_CHAR(c);
+	return islower((byte)c);
+}
+
+bool isSpace(int c) {
+	ENSURE_ASCII_CHAR(c);
+	return isspace((byte)c);
+}
+
+bool isUpper(int c) {
+	ENSURE_ASCII_CHAR(c);
+	return isupper((byte)c);
+}
+
 } // End of namespace Common