Checking only ISO Latin 1 digits for IPs

Author: eyalkoren

x-pack/plugin/mapper-patterned-text/src/main/java/org/elasticsearch/xpack/patternedtext/PatternedTextValueProcessor.java

@@ -187,7 +187,8 @@ public static boolean isIpv4_manual_iterative(String text) {
                     return false;
                 }
                 octet = 0;
-            } else if (Character.isDigit(c)) {
+            } else if ('0' <= c && c <= '9') {
+                // Character.isDigit(c) is invalid for IPs and inconsistent with the calculation of the numeric value of the character
                 octet = octet * 10 + c - '0';
                 if (octet > 255) {
                     return false;