fix is_wp_version_compatible() to accommodate incorrect format x.x.0

src/wp-includes/functions.php

@@ -8716,6 +8716,16 @@ function is_wp_version_compatible( $required ) {
 	// Strip off any -alpha, -RC, -beta, -src suffixes.
 	list( $version ) = explode( '-', $wp_version );
 
+	if ( is_string( $required ) && substr_count( $required, '.' ) > 1 && str_ends_with( $required, '.0' ) ) {
+		error_log(
+			__FUNCTION__ . '(): ' .
+			/* translators: s: version string sent to function */
+			sprintf( __( '`%s` Not a valid WordPress version string.' ), $required )
+		);
+
+		$required = rtrim( $required, '.0' );
+	}
+
 	return empty( $required ) || version_compare( $version, $required, '>=' );
 }
 

tests/phpunit/tests/functions/isWpVersionCompatible.php

@@ -85,6 +85,32 @@ public function data_is_wp_version_compatible() {
 				'required' => array(),
 				'expected' => true,
 			),
+
+			// Improper WP version.
+			'improper trailing x.x.0'   => array(
+				'required' => '5.2.0',
+				'expected' => true,
+			),
+			'correct version'           => array(
+				'required' => '5.2',
+				'expected' => true,
+			),
+			'incorrect trailing x.0.0'  => array(
+				'required' => '5.0.0',
+				'expected' => true,
+			),
+			'correct version x.0'       => array(
+				'required' => '5.0',
+				'expected' => true,
+			),
+			'correct version x.0.1'     => array(
+				'required' => '5.0.1',
+				'expected' => true,
+			),
+			'correct version x.1.1'     => array(
+				'required' => '5.1.1',
+				'expected' => true,
+			),
 		);
 	}