graphql-java
diff --git a/‎src/main/java/graphql/schema/PropertyFetchingImpl.java‎
Lines changed: 4 additions & 1 deletion b/‎src/main/java/graphql/schema/PropertyFetchingImpl.java‎
Lines changed: 4 additions & 1 deletion
diff --git a/‎src/main/java/graphql/util/StringKit.java‎
Lines changed: 20 additions & 0 deletions b/‎src/main/java/graphql/util/StringKit.java‎
Lines changed: 20 additions & 0 deletions
diff --git a/‎src/test/groovy/graphql/schema/PropertyDataFetcherTest.groovy‎
Lines changed: 32 additions & 0 deletions b/‎src/test/groovy/graphql/schema/PropertyDataFetcherTest.groovy‎
Lines changed: 32 additions & 0 deletions
diff --git a/‎src/test/groovy/graphql/util/StringKitTest.groovy‎
Lines changed: 22 additions & 0 deletions b/‎src/test/groovy/graphql/util/StringKitTest.groovy‎
Lines changed: 22 additions & 0 deletions
@@ -3,6 +3,8 @@
 import graphql.GraphQLException;
 import graphql.Internal;
 import graphql.schema.fetching.LambdaFetchingSupport;
+import graphql.util.EscapeUtil;
+import graphql.util.StringKit;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -12,6 +14,7 @@
 import java.lang.reflect.Modifier;
 import java.util.Arrays;
 import java.util.Comparator;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
@@ -213,7 +216,7 @@ private Object getPropertyViaGetterMethod(Object object, String propertyName, Gr
     }
 
     private Object getPropertyViaGetterUsingPrefix(Object object, String propertyName, String prefix, MethodFinder methodFinder, Supplier<Object> singleArgumentValue) throws NoSuchMethodException {
-        String getterName = prefix + propertyName.substring(0, 1).toUpperCase() + propertyName.substring(1);
+        String getterName = prefix + StringKit.capitalize(propertyName);
         Method method = methodFinder.apply(object.getClass(), getterName);
         return invokeMethod(object, singleArgumentValue, method, takesSingleArgumentTypeAsOnlyArgument(method));
     }
 
@@ -0,0 +1,20 @@
+package graphql.util;
+
+import java.util.Locale;
+
+public class StringKit {
+
+    public static String capitalize(String s) {
+        if (s != null && !s.isEmpty()) {
+            StringBuilder sb = new StringBuilder();
+            // see https://github.com/graphql-java/graphql-java/issues/3385
+            sb.append(s.substring(0, 1).toUpperCase(Locale.ROOT));
+            if (s.length() > 1) {
+                sb.append(s.substring(1));
+            }
+            return sb.toString();
+        }
+        return s;
+    }
+
+}
@@ -637,6 +637,38 @@ class PropertyDataFetcherTest extends Specification {
         result == "bar"
     }
 
+    class BaseObject {
+        private String id
+
+        String getId() {
+            return id
+        }
+
+        void setId(String value) {
+            id = value;
+        }
+    }
+
+    class OtherObject extends BaseObject {}
+
+    def "Can access private property from base class that starts with i in Turkish"() {
+        // see https://github.com/graphql-java/graphql-java/issues/3385
+        given:
+        Locale oldLocale = Locale.getDefault()
+        Locale.setDefault(new Locale("tr", "TR"))
+
+        def environment = env(new OtherObject(id: "aValue"))
+        def fetcher = PropertyDataFetcher.fetching("id")
+
+        when:
+        String propValue = fetcher.get(environment)
+
+        then:
+        propValue == 'aValue'
+
+        cleanup:
+        Locale.setDefault(oldLocale)
+    }
     /**
      * Classes from issue to ensure we reproduce as reported by customers
      *
 
@@ -0,0 +1,22 @@
+package graphql.util
+
+import spock.lang.Specification
+
+class StringKitTest extends Specification {
+
+
+    def "can capitalise"() {
+        expect:
+
+        def actual = StringKit.capitalize(input)
+        actual == expected
+
+        where:
+        input | expected
+        null  | null
+        ""    | ""
+        "a"   | "A"
+        "abc" | "Abc"
+
+    }
+}