From 50887904a9ec9756796b2916e13cccd7a415d013 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 1 Mar 2026 15:31:51 +0000
Subject: [PATCH 1/2] Initial plan


From a9db3c1dee5e6bada992388d560a1371f40c0765 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sun, 1 Mar 2026 15:37:14 +0000
Subject: [PATCH 2/2] Fix phone number format: avoid misidentifying escaped
 literal chars as grouping chars, fix decimal cast in SSN/Zip/Phone format
 classes

Co-authored-by: tonyqus <772561+tonyqus@users.noreply.github.com>
---
 main/SS/UserModel/DataFormatter.cs               |  7 +++++--
 main/SS/Util/Format.cs                           |  6 +++---
 testcases/main/SS/UserModel/TestDataFormatter.cs | 13 +++++++++++++
 3 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/main/SS/UserModel/DataFormatter.cs b/main/SS/UserModel/DataFormatter.cs
index b248d6e350..5eba099ac2 100644
--- a/main/SS/UserModel/DataFormatter.cs
+++ b/main/SS/UserModel/DataFormatter.cs
@@ -894,12 +894,15 @@ public override object ParseObject(string source, int pos)
 
         private FormatBase CreateNumberFormat(string formatStr, double cellValue)
         {
+            // Check for alternate grouping BEFORE cleaning (backslash stripping) so that
+            // escaped literal characters like \- are not misidentified as grouping chars.
+            // eg for a format like #'##0 which wants 12'345 not 12,345
+            Match agm = alternateGrouping.Match(formatStr);
+
             string format = cleanFormatForNumber(formatStr);
             NumberFormatInfo symbols = decimalSymbols;
 
             // Do we need to change the grouping character?
-            // eg for a format like #'##0 which wants 12'345 not 12,345
-            Match agm = alternateGrouping.Match(format);
             if (agm.Success)
             {
                 char grouping = agm.Groups[2].Value[0];
diff --git a/main/SS/Util/Format.cs b/main/SS/Util/Format.cs
index 0d3ffd683e..4a6f4cd98e 100644
--- a/main/SS/Util/Format.cs
+++ b/main/SS/Util/Format.cs
@@ -58,7 +58,7 @@ private SSNFormat()
         /** Format a number as an SSN */
         public override string Format(object obj, CultureInfo culture)
         {
-            var result = ((double)obj).ToString(df, culture);
+            var result = Convert.ToDouble(obj, CultureInfo.InvariantCulture).ToString(df, culture);
             var sb = new StringBuilder();
             sb.Append(result.Substring(0, 3)).Append('-');
             sb.Append(result.Substring(3, 2)).Append('-');
@@ -99,7 +99,7 @@ private ZipPlusFourFormat()
         /** Format a number as Zip + 4 */
         public override string Format(object obj, CultureInfo culture)
         {
-            var result = ((double)obj).ToString(df, culture);
+            var result = Convert.ToDouble(obj, CultureInfo.InvariantCulture).ToString(df, culture);
             return result.Substring(0, 5)+'-'+result.Substring(5, 4);
         }
 
@@ -137,7 +137,7 @@ private PhoneFormat()
         /** Format a number as a phone number */
         public override string Format(object obj, CultureInfo culture)
         {
-            var result = ((double)obj).ToString(df, culture);
+            var result = Convert.ToDouble(obj, CultureInfo.InvariantCulture).ToString(df, culture);
             var sb = new StringBuilder();
             String seg1, seg2, seg3;
             var len = result.Length;
diff --git a/testcases/main/SS/UserModel/TestDataFormatter.cs b/testcases/main/SS/UserModel/TestDataFormatter.cs
index 0862ab6d70..3982a5c0cf 100644
--- a/testcases/main/SS/UserModel/TestDataFormatter.cs
+++ b/testcases/main/SS/UserModel/TestDataFormatter.cs
@@ -894,6 +894,19 @@ Excel displays the month instead of minutes."
          * bug 60422 : DataFormatter has issues with a specific NumberFormat in Germany default locale
          * Currently, this test only passes if you set LocaleUtil.setUserLocale(Locale.ROOT) or Locale.US.
          */
+        [Test]
+        public void TestPhoneNumberFormat()
+        {
+            DataFormatter formatter = new DataFormatter(CultureInfo.GetCultureInfo("en-US"));
+
+            // Bug: alternateGrouping regex should not misidentify escaped literal '-' as a grouping character
+            ClassicAssert.AreEqual("(123) 456-7890", formatter.FormatRawCellContents(1234567890, -1, "[<=9999999]###\\-####;\\(###\\)\\ ###\\-####"));
+            ClassicAssert.AreEqual("123-456-7890", formatter.FormatRawCellContents(1234567890, -1, "###\\-###\\-####"));
+
+            // Bug: SSNFormat/ZipPlusFourFormat/PhoneFormat must handle decimal values passed by FormatRawCellContents
+            ClassicAssert.AreEqual("(123) 456-7890", formatter.FormatRawCellContents(1234567890, -1, "[<=9999999]###-####;(###) ###-####"));
+        }
+
         [Test]
         public void TestBug60422()
         {