From 5e8c9dd33769d081b174e39b3e9037e16c100761 Mon Sep 17 00:00:00 2001
From: Evgen Bielozorov <yevhenbielozorov@gmail.com>
Date: Wed, 29 Jul 2026 16:24:56 +0200
Subject: [PATCH] fix: use locale-independent digits in temporal toString
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Month, Minute, Second and Timespan render their value via DecimalFormat with
the JVM default locale, so under locales whose default digits are not 0-9
(Arabic, Persian, Bengali, ...) toString emitted non-ASCII digits, e.g.
Month(22) -> "٢٠٠١-١١" instead of "2001-11". These are the canonical textual
forms of kdb+ temporal atoms and must always use ASCII digits.

Format i2()/i9() with DecimalFormatSymbols for Locale.ROOT so the output is
identical regardless of the JVM default locale. Add a test that pins the
digits under an Arabic-Indic locale.
---
 javakdb/src/main/java/com/kx/c.java     |  6 ++++--
 javakdb/src/test/java/com/kx/CTest.java | 17 +++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/javakdb/src/main/java/com/kx/c.java b/javakdb/src/main/java/com/kx/c.java
index 93f078a..2bfe5c6 100644
--- a/javakdb/src/main/java/com/kx/c.java
+++ b/javakdb/src/main/java/com/kx/c.java
@@ -39,8 +39,10 @@
 import java.time.Instant;
 import java.time.ZoneOffset;
 import java.text.DecimalFormat;
+import java.text.DecimalFormatSymbols;
 import java.util.Arrays;
 import java.util.Calendar;
+import java.util.Locale;
 import java.util.TimeZone;
 import java.util.UUID;
 import javax.net.ssl.SSLSocket;
@@ -2033,7 +2035,7 @@ public static Flip td(Object tbl) throws UnsupportedEncodingException{
    * @return String representation of int with zero padding
    */
   static String i2(int i){
-    return new DecimalFormat("00").format(i);
+    return new DecimalFormat("00",DecimalFormatSymbols.getInstance(Locale.ROOT)).format(i);
   }
   /**
    * Creates a string from int with left padding of 0s, if less than 9 digits
@@ -2041,6 +2043,6 @@ static String i2(int i){
    * @return String representation of int with zero padding
    */
   static String i9(int i){
-    return new DecimalFormat("000000000").format(i);
+    return new DecimalFormat("000000000",DecimalFormatSymbols.getInstance(Locale.ROOT)).format(i);
   }
 }
diff --git a/javakdb/src/test/java/com/kx/CTest.java b/javakdb/src/test/java/com/kx/CTest.java
index 330ce2b..4d505e7 100644
--- a/javakdb/src/test/java/com/kx/CTest.java
+++ b/javakdb/src/test/java/com/kx/CTest.java
@@ -1105,6 +1105,23 @@ public void testTimespanToString()
         Assert.assertEquals("", mon.toString());
     }
 
+    @Test
+    public void testTemporalToStringLocaleIndependent()
+    {
+        // The canonical kdb+ textual form of temporal types must always use ASCII digits,
+        // independent of the JVM default locale (e.g. Arabic-Indic digit locales).
+        java.util.Locale previous = java.util.Locale.getDefault();
+        try {
+            java.util.Locale.setDefault(java.util.Locale.forLanguageTag("ar-EG"));
+            Assert.assertEquals("2001-11", new c.Month(22).toString());
+            Assert.assertEquals("00:22", new c.Minute(22).toString());
+            Assert.assertEquals("00:00:22", new c.Second(22).toString());
+            Assert.assertEquals("00:00:00.000000022", new c.Timespan(22).toString());
+        } finally {
+            java.util.Locale.setDefault(previous);
+        }
+    }
+
     @Test
     public void testTimespanEquals()
     {