REST API: Allow posts to be published with a publication date of midn…

…ight 1970-01-01.

Explicitly checks date parsing return values for `false`, so that `0` (the value returned for the UNIX epoch of `1970-01-01 00:00:00`) is correctly treated as a valid timestamp.

It should be valid to create a post dated to any point in history.

Props emmanuel78, sabernhardt, siliconforks, drjosh07, antpb, TimothyBlynJacobs.
Fixes #60184.




git-svn-id: https://develop.svn.wordpress.org/trunk@59040 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/rest-api.php

@@ -1304,6 +1304,9 @@ function rest_get_avatar_sizes() {
 /**
  * Parses an RFC3339 time into a Unix timestamp.
  *
+ * Explicitly check for `false` to detect failure, as zero is a valid return
+ * value on success.
+ *
  * @since 4.4.0
  *
  * @param string $date      RFC3339 timestamp.
@@ -1369,7 +1372,7 @@ function rest_get_date_with_gmt( $date, $is_utc = false ) {
 
 	$date = rest_parse_date( $date );
 
-	if ( empty( $date ) ) {
+	if ( false === $date ) {
 		return null;
 	}
 
@@ -2259,7 +2262,7 @@ function rest_validate_value_from_schema( $value, $args, $param = '' ) {
 				break;
 
 			case 'date-time':
-				if ( ! rest_parse_date( $value ) ) {
+				if ( false === rest_parse_date( $value ) ) {
 					return new WP_Error( 'rest_invalid_date', __( 'Invalid date.' ) );
 				}
 				break;

tests/phpunit/tests/rest-api/rest-schema-validation.php

@@ -1020,6 +1020,17 @@ public function test_nullable_date() {
 		$this->assertSame( 'Invalid date.', $error->get_error_message() );
 	}
 
+	/**
+	 * @ticket 60184
+	 */
+	public function test_epoch() {
+		$schema = array(
+			'type'   => 'string',
+			'format' => 'date-time',
+		);
+		$this->assertTrue( rest_validate_value_from_schema( '1970-01-01T00:00:00Z', $schema ) );
+	}
+
 	public function test_object_or_string() {
 		$schema = array(
 			'type'       => array( 'object', 'string' ),