From 3fac2c5c98015bd591dbf358c6b43c3aa35f577e Mon Sep 17 00:00:00 2001
From: Tom Clegg <t@clegg.dev>
Date: Tue, 1 Jun 2021 10:41:40 -0500
Subject: [PATCH] Always use preferred intl prefix if present

---
 .../PhoneNumbers.Test/TestBuildMetadataFromXml.cs |  4 ++--
 csharp/PhoneNumbers.Test/TestPhoneNumberUtil.cs   |  3 +++
 csharp/PhoneNumbers/PhoneNumberUtil.cs            | 15 ++++++++-------
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/csharp/PhoneNumbers.Test/TestBuildMetadataFromXml.cs b/csharp/PhoneNumbers.Test/TestBuildMetadataFromXml.cs
index 61e6016c9..3b029a112 100644
--- a/csharp/PhoneNumbers.Test/TestBuildMetadataFromXml.cs
+++ b/csharp/PhoneNumbers.Test/TestBuildMetadataFromXml.cs
@@ -92,7 +92,7 @@ public void TestLoadTerritoryTagMetadata()
         {
             var xmlInput =
                 "<territory countryCode='33' leadingDigits='2' internationalPrefix='00'" +
-                "           preferredInternationalPrefix='0011' nationalPrefixForParsing='0'" +
+                "           preferredInternationalPrefix='00~11' nationalPrefixForParsing='0'" +
                 "           nationalPrefixTransformRule='9$1'" + // nationalPrefix manually injected.
                 "           preferredExtnPrefix=' x' mainCountryForCode='true'" +
                 "           leadingZeroPossible='true' mobileNumberPortableRegion='true'>" +
@@ -103,7 +103,7 @@ public void TestLoadTerritoryTagMetadata()
             Assert.Equal(33, phoneMetadata.CountryCode);
             Assert.Equal("2", phoneMetadata.LeadingDigits);
             Assert.Equal("00", phoneMetadata.InternationalPrefix);
-            Assert.Equal("0011", phoneMetadata.PreferredInternationalPrefix);
+            Assert.Equal("00~11", phoneMetadata.PreferredInternationalPrefix);
             Assert.Equal("0", phoneMetadata.NationalPrefixForParsing);
             Assert.Equal("9$1", phoneMetadata.NationalPrefixTransformRule);
             Assert.Equal("0", phoneMetadata.NationalPrefix);
diff --git a/csharp/PhoneNumbers.Test/TestPhoneNumberUtil.cs b/csharp/PhoneNumbers.Test/TestPhoneNumberUtil.cs
index e67e6c6a5..28641b1c7 100644
--- a/csharp/PhoneNumbers.Test/TestPhoneNumberUtil.cs
+++ b/csharp/PhoneNumbers.Test/TestPhoneNumberUtil.cs
@@ -609,6 +609,9 @@ public void TestFormatOutOfCountryWithPreferredIntlPrefix()
             // are accepted as possible international prefixes in our test metadta.)
             Assert.Equal("0011 39 02 3661 8300",
                 phoneUtil.FormatOutOfCountryCallingNumber(ITNumber, RegionCode.AU));
+
+            // Testing preferred international prefixes with ~ are supported (designates waiting).
+            Assert.Equal("8~10 39 02 3661 8300", phoneUtil.FormatOutOfCountryCallingNumber(ITNumber, RegionCode.UZ));
         }
 
         [Fact]
diff --git a/csharp/PhoneNumbers/PhoneNumberUtil.cs b/csharp/PhoneNumbers/PhoneNumberUtil.cs
index b6a98b519..8e5b004a2 100644
--- a/csharp/PhoneNumbers/PhoneNumberUtil.cs
+++ b/csharp/PhoneNumbers/PhoneNumberUtil.cs
@@ -1462,18 +1462,19 @@ public string FormatOutOfCountryCallingNumber(PhoneNumber number, string regionC
             var metadataForRegionCallingFrom = GetMetadataForRegion(regionCallingFrom);
             var internationalPrefix = metadataForRegionCallingFrom.InternationalPrefix;
 
-            // For regions that have multiple international prefixes, the international format of the
-            // number is returned, unless there is a preferred international prefix.
+            // In general, if there is a preferred international prefix, use that. Otherwise, for regions
+            // that have multiple international prefixes, the international format of the number is
+            // returned since we would not know which one to use.
             var internationalPrefixForFormatting = "";
-            if (UniqueInternationalPrefix.IsMatchAll(internationalPrefix))
-            {
-                internationalPrefixForFormatting = internationalPrefix;
-            }
-            else if (metadataForRegionCallingFrom.HasPreferredInternationalPrefix)
+            if (metadataForRegionCallingFrom.HasPreferredInternationalPrefix)
             {
                 internationalPrefixForFormatting =
                     metadataForRegionCallingFrom.PreferredInternationalPrefix;
             }
+            else if (UniqueInternationalPrefix.IsMatchAll(internationalPrefix))
+            {
+                internationalPrefixForFormatting = internationalPrefix;
+            }
 
             var regionCode = GetRegionCodeForCountryCode(countryCallingCode);
             var metadataForRegion =