Add debug log for 5914560 and 6383850

This won't be shown in usual condition since in most cases the method
will just use the block just above the logging and return true/false
there. On the other hand this might be useful if the case is truely
exceptional and thus this path is really used.

Bug: 5914560
Bug: 6383850
Change-Id: I2242f93a9b905b5a39d997aa30d9fd6f5bfbdf49

Author: Daisuke Miyakawa

telephony/java/android/telephony/PhoneNumberUtils.java

@@ -1711,6 +1711,13 @@ private static boolean isEmergencyNumberInternal(String number,
             return false;
         }
 
+        // STOPSHIP: remove this after figuring out issue 5914560, 6383850.
+        Log.d(LOG_TAG, "System property doesn't provide any emergency numbers."
+                + " Use embedded logic for determining emergency numbers."
+                + " number: " + toLogSafePhoneNumber(number)
+                + ", Iso: " + defaultCountryIso
+                + ", useExactMatch: " + useExactMatch);
+
         // No ecclist system property, so use our own list.
         if (defaultCountryIso != null) {
             ShortNumberUtil util = new ShortNumberUtil();
@@ -1728,6 +1735,21 @@ private static boolean isEmergencyNumberInternal(String number,
         }
     }
 
+    private static String toLogSafePhoneNumber(String number) {
+        // Do exactly same thing as Uri#toSafeString() does, which will enable us to compare
+        // sanitized phone numbers.
+        StringBuilder builder = new StringBuilder();
+        for (int i = 0; i < number.length(); i++) {
+            char c = number.charAt(i);
+            if (c == '-' || c == '@' || c == '.') {
+                builder.append(c);
+            } else {
+                builder.append('x');
+            }
+        }
+        return builder.toString();
+    }
+
     /**
      * Checks if a given number is an emergency number for the country that the user is in. The
      * current country is determined using the CountryDetector.