Fix #5052: Minor bug in FirstCharBasedValidator.forFirstNameRule(): returns null in non-default case

Author: cowtowncoder

release-notes/VERSION-2.x

@@ -76,6 +76,8 @@ Project: jackson-databind
   failure of `java.util.Optional` (de)serialization without Java 8 module
 #5014: Add `java.lang.Runnable` as unsafe base type in `DefaultBaseTypeLimitingValidator`
 #5020: Support new `@JsonProperty.isRequired` for overridable definition of "required-ness"
+#5052: Minor bug in `FirstCharBasedValidator.forFirstNameRule()`: returns `null`
+  in non-default case
 
 2.18.3 (28-Feb-2025)
 

src/main/java/com/fasterxml/jackson/databind/introspect/DefaultAccessorNamingStrategy.java

@@ -504,11 +504,11 @@ protected FirstCharBasedValidator(boolean allowLowerCaseFirstChar,
          *    consider difference between "setter-methods" {@code setValue()} and {@code set_value()}.
          *
          * @return Validator instance to use, if any; {@code null} to indicate no additional
-         *   rules applied (case when both arguments are {@code false})
+         *   rules applied (case when both arguments are {@code true})
          */
         public static BaseNameValidator forFirstNameRule(boolean allowLowerCaseFirstChar,
                 boolean allowNonLetterFirstChar) {
-            if (!allowLowerCaseFirstChar && !allowNonLetterFirstChar) {
+            if (allowLowerCaseFirstChar && allowNonLetterFirstChar) {
                 return null;
             }
             return new FirstCharBasedValidator(allowLowerCaseFirstChar,