Make profile activation conditions locale-independent

impl/maven-impl/src/main/java/org/apache/maven/impl/model/profile/ConditionFunctions.java

@@ -19,6 +19,7 @@
 package org.apache.maven.impl.model.profile;
 
 import java.util.List;
+import java.util.Locale;
 
 import org.apache.maven.api.services.InterpolatorException;
 import org.apache.maven.api.services.ModelBuilderException;
@@ -65,6 +66,9 @@ public Object length(List<Object> args) {
 
     /**
      * Converts the given string to uppercase.
+     * <p>
+     * The conversion uses {@link Locale#ROOT} so that profile activation does not depend on the
+     * default locale of the machine running the build.
      *
      * @param args A list containing a single string argument
      * @return The uppercase version of the input string
@@ -75,11 +79,14 @@ public Object upper(List<Object> args) {
             throw new IllegalArgumentException("upper function requires exactly one argument");
         }
         String s = ConditionParser.toString(args.get(0));
-        return s.toUpperCase();
+        return s.toUpperCase(Locale.ROOT);
     }
 
     /**
      * Converts the given string to lowercase.
+     * <p>
+     * The conversion uses {@link Locale#ROOT} so that profile activation does not depend on the
+     * default locale of the machine running the build.
      *
      * @param args A list containing a single string argument
      * @return The lowercase version of the input string
@@ -90,7 +97,7 @@ public Object lower(List<Object> args) {
             throw new IllegalArgumentException("lower function requires exactly one argument");
         }
         String s = ConditionParser.toString(args.get(0));
-        return s.toLowerCase();
+        return s.toLowerCase(Locale.ROOT);
     }
 
     /**

impl/maven-impl/src/main/java/org/apache/maven/impl/model/profile/ConditionParser.java

@@ -20,6 +20,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.function.UnaryOperator;
 
@@ -554,6 +555,11 @@ private static Object compare(Object left, String operator, Object right) {
      * Converts an object to a string representation.
      * If the object is a {@code Double}, it formats it without any decimal places.
      * Otherwise, it uses the {@code String.valueOf} method.
+     * <p>
+     * Formatting uses {@link Locale#ROOT} so that profile activation does not depend on the
+     * default locale of the machine running the build. Without it, a locale whose default
+     * numbering system is not latin (for example {@code hi-IN-u-nu-deva}) would render
+     * {@code 42} as {@code ४२}.
      *
      * @param value the object to convert to a string
      * @return the string representation of the object
@@ -562,7 +568,7 @@ public static String toString(Object value) {
         if (value instanceof Double || value instanceof Float) {
             double doubleValue = ((Number) value).doubleValue();
             if (doubleValue == Math.floor(doubleValue) && !Double.isInfinite(doubleValue)) {
-                return String.format("%.0f", doubleValue);
+                return String.format(Locale.ROOT, "%.0f", doubleValue);
             }
         }
         return String.valueOf(value);

impl/maven-impl/src/test/java/org/apache/maven/impl/model/profile/ConditionParserTest.java

@@ -18,6 +18,7 @@
  */
 package org.apache.maven.impl.model.profile;
 
+import java.util.Locale;
 import java.util.Map;
 import java.util.function.UnaryOperator;
 
@@ -94,6 +95,49 @@ void testCaseConversionFunctions() {
         assertEquals("world", parser.parse("lower('WORLD')"));
     }
 
+    /**
+     * The result of {@code upper()} and {@code lower()} must not depend on the default locale of
+     * the machine running the build. In the Turkish locale the default case mapping turns
+     * {@code i} into the dotted {@code İ} and {@code I} into the dotless {@code ı}, which would
+     * silently change whether a profile is activated.
+     */
+    @Test
+    void testCaseConversionFunctionsAreLocaleIndependent() {
+        Locale orig = Locale.getDefault();
+        try {
+            Locale[] locales = {Locale.ENGLISH, new Locale("tr")};
+            for (Locale locale : locales) {
+                Locale.setDefault(locale);
+                assertEquals("WINDOWS", parser.parse("upper('windows')"), "upper() in " + locale);
+                assertEquals("LINUX", parser.parse("upper('linux')"), "upper() in " + locale);
+                assertEquals("linux", parser.parse("lower('LINUX')"), "lower() in " + locale);
+                assertEquals("ci", parser.parse("lower('CI')"), "lower() in " + locale);
+            }
+        } finally {
+            Locale.setDefault(orig);
+        }
+    }
+
+    /**
+     * Numbers must render with latin digits regardless of the default locale, otherwise a
+     * condition comparing against a string literal would evaluate differently on a machine
+     * whose locale uses a non-latin numbering system.
+     */
+    @Test
+    void testNumberFormattingIsLocaleIndependent() {
+        Locale orig = Locale.getDefault();
+        try {
+            // this locale's default numbering system is Devanagari rather than latin
+            Locale.setDefault(Locale.forLanguageTag("hi-IN-u-nu-deva"));
+            assertEquals("42", ConditionParser.toString(42.0));
+            assertEquals("42", ConditionParser.toString(42.0f));
+            assertEquals("The answer is 42", parser.parse("'The answer is ' + 42.0"));
+            assertEquals(2, parser.parse("length(42.0)"));
+        } finally {
+            Locale.setDefault(orig);
+        }
+    }
+
     @Test
     void testConcatFunction() {
         assertEquals("HelloWorld", parser.parse("'Hello' + 'World'"));