Fix #651: Support TIME_IN_MILLIS and locale-only @JsonbDateFormat on creator parameters

AnnotationIntrospector.getConstructorDateFormatter() always passed the
value of @JsonbDateFormat to DateTimeFormatter.ofPattern(), including
the TIME_IN_MILLIS and DEFAULT_FORMAT markers, so deserializing a record
or a @JsonbCreator parameter annotated with
@JsonbDateFormat(TIME_IN_MILLIS), or with only a locale, failed with
"Pattern includes reserved character: '#'".

Handle these two markers as for properties: they are not patterns, the
date converters use the epoch millis or the default formats for them.

Signed-off-by: Sharang Gupta <sharang@sharanggupta.dev>

src/main/java/org/eclipse/yasson/internal/AnnotationIntrospector.java

diff --git a/src/main/java/org/eclipse/yasson/internal/AnnotationIntrospector.java b/src/main/java/org/eclipse/yasson/internal/AnnotationIntrospector.java
index 2228c51..8edc2af 100644
--- a/src/main/java/org/eclipse/yasson/internal/AnnotationIntrospector.java
+++ b/src/main/java/org/eclipse/yasson/internal/AnnotationIntrospector.java
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2016, 2026 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2026 Contributors to the Eclipse Foundation
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -594,9 +595,16 @@
      */
     public JsonbDateFormatter getConstructorDateFormatter(JsonbAnnotatedElement<Parameter> param) {
         return param.getAnnotation(JsonbDateFormat.class)
-                .map(annotation -> new JsonbDateFormatter(DateTimeFormatter.ofPattern(annotation.value(),
-                                                                                      Locale.forLanguageTag(annotation.locale())),
-                                                          annotation.value(), annotation.locale()))
+                .map(annotation -> {
+                    String format = annotation.value();
+                    String locale = annotation.locale();
+                    if (JsonbDateFormat.TIME_IN_MILLIS.equals(format) || JsonbDateFormat.DEFAULT_FORMAT.equals(format)) {
+                        //not patterns, handled by the date converters as for properties
+                        return new JsonbDateFormatter(format, locale);
+                    }
+                    return new JsonbDateFormatter(DateTimeFormatter.ofPattern(format, Locale.forLanguageTag(locale)),
+                                                  format, locale);
+                })
                 .orElse(null);
     }
 

src/test/java/org/eclipse/yasson/records/RecordTest.java

diff --git a/src/test/java/org/eclipse/yasson/records/RecordTest.java b/src/test/java/org/eclipse/yasson/records/RecordTest.java
index edaee35..bf3ad00 100644
--- a/src/test/java/org/eclipse/yasson/records/RecordTest.java
+++ b/src/test/java/org/eclipse/yasson/records/RecordTest.java
@@ -24,6 +24,8 @@
 import org.eclipse.yasson.internal.properties.Messages;
 import org.junit.jupiter.api.Test;
 
+import java.time.Instant;
+import java.time.LocalDate;
 import java.util.List;
 import java.util.Set;
 
@@ -50,6 +52,18 @@
     }
 
     @Test
+    public void testRecordWithDateFormats() {
+        String json = "{\"iso\":\"2024-10-11T13:28:22Z\",\"localeOnly\":\"2024-10-11\",\"millis\":1728574424000}";
+
+        RecordWithDateFormats deserialized = Jsonbs.defaultJsonb.fromJson(json, RecordWithDateFormats.class);
+
+        assertEquals(Instant.ofEpochMilli(1728574424000L), deserialized.millis());
+        assertEquals(LocalDate.of(2024, 10, 11), deserialized.localeOnly());
+        assertEquals(Instant.parse("2024-10-11T13:28:22Z"), deserialized.iso());
+        assertEquals(json, Jsonbs.defaultJsonb.toJson(deserialized));
+    }
+
+    @Test
     public void testRecordProcessingWithoutJsonbProperties() {
         CarWithoutAnnotations car = new CarWithoutAnnotations("skoda", "green");
         String expected = "{\"color\":\"green\",\"type\":\"skoda\"}";

src/test/java/org/eclipse/yasson/records/RecordWithDateFormats.java

diff --git a/src/test/java/org/eclipse/yasson/records/RecordWithDateFormats.java b/src/test/java/org/eclipse/yasson/records/RecordWithDateFormats.java
new file mode 100644
index 0000000..a247f13
--- /dev/null
+++ b/src/test/java/org/eclipse/yasson/records/RecordWithDateFormats.java
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2026 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+
+package org.eclipse.yasson.records;
+
+import java.time.Instant;
+import java.time.LocalDate;
+
+import jakarta.json.bind.annotation.JsonbDateFormat;
+
+public record RecordWithDateFormats(@JsonbDateFormat(JsonbDateFormat.TIME_IN_MILLIS) Instant millis,
+                                    @JsonbDateFormat(locale = "de") LocalDate localeOnly,
+                                    Instant iso) {
+}