Widget Visibility: Fix thrown PHP error under specific block conditions (#45087)

Author: LiamSarsfield

projects/plugins/jetpack/changelog/fix-widget-visibility-array-string-conversion-error-hog-336

@@ -0,0 +1,4 @@
+Significance: patch
+Type: bugfix
+
+Widget Visibility: Fix thrown PHP error under specific block conditions

projects/plugins/jetpack/modules/widget-visibility/widget-conditions.php

@@ -799,6 +799,40 @@ public static function generate_condition_key( $rule ) {
 		return $rule['major'] . ':' . $rule['minor'];
 	}
 
+	/**
+	 * Normalize widget `content` into a string suitable for block scanning.
+	 *
+	 * @since $$next-version$$
+	 *
+	 * @param mixed $content The widget instance 'content' value.
+	 * @return string|false Normalized string content or false if none.
+	 */
+	private static function normalize_widget_content( $content ) {
+		if ( empty( $content ) ) {
+			return false;
+		}
+
+		if ( is_string( $content ) ) {
+			return $content;
+		}
+
+		if ( ! is_array( $content ) ) {
+			return false;
+		}
+
+		if ( isset( $content['content'] ) && is_string( $content['content'] ) ) {
+			return $content['content'];
+		}
+
+		if ( isset( $content[0] ) && is_array( $content[0] ) && isset( $content[0]['blockName'] ) ) {
+			// Looks like a parsed blocks array.
+			return serialize_blocks( $content );
+		}
+
+		// Unknown array shape: treat as no visibility rules.
+		return false;
+	}
+
 	/**
 	 * Determine whether the widget should be displayed based on conditions set by the user.
 	 *
@@ -826,36 +860,45 @@ public static function filter_widget( $instance ) {
 				return $instance;
 			}
 			return false;
-		} elseif ( ! empty( $instance['content'] ) && has_blocks( $instance['content'] ) ) {
-			$scanner = Block_Scanner::create( $instance['content'] );
-			if ( ! $scanner ) {
-				// No Rules: Display widget.
-				return $instance;
-			}
+		}
 
-			// Find the first block that opens
-			while ( $scanner->next_delimiter() ) {
-				if ( ! $scanner->opens_block() ) {
-					continue;
-				}
+		if ( empty( $instance['content'] ) ) {
+			return $instance;
+		}
+		$content = self::normalize_widget_content( isset( $instance['content'] ) ? $instance['content'] : null );
 
-				$attributes = $scanner->allocate_and_return_parsed_attributes();
+		if ( false === $content || ! has_blocks( $content ) ) {
+			// No visibility found.
+			return $instance;
+		}
 
-				if ( ! is_array( $attributes ) || empty( $attributes['conditions']['rules'] ) ) {
-					// No Rules: Display widget.
-					return $instance;
-				}
+		$scanner = Block_Scanner::create( $content );
+		if ( ! $scanner ) {
+			// No Rules: Display widget.
+			return $instance;
+		}
 
-				if ( self::filter_widget_check_conditions( $attributes['conditions'] ) ) {
-					// Rules passed checks: Display widget.
-					return $instance;
-				}
+		// Find the first block that opens
+		while ( $scanner->next_delimiter() ) {
+			if ( ! $scanner->opens_block() ) {
+				continue;
+			}
+
+			$attributes = $scanner->allocate_and_return_parsed_attributes();
 
-				// Rules failed checks: Hide widget.
-				return false;
+			if ( ! is_array( $attributes ) || empty( $attributes['conditions']['rules'] ) ) {
+				// No Rules: Display widget.
+				return $instance;
 			}
-		}
 
+			if ( self::filter_widget_check_conditions( $attributes['conditions'] ) ) {
+				// Rules passed checks: Display widget.
+				return $instance;
+			}
+
+			// Rules failed checks: Hide widget.
+			return false;
+		}
 		// No visibility found.
 		return $instance;
 	}

projects/plugins/jetpack/tests/php/modules/widget-visibility/Jetpack_Widget_Conditions_Test.php

@@ -59,4 +59,49 @@ public function test_filter_widget() {
 		$return_val = Jetpack_Widget_Conditions::filter_widget( $block );
 		$this->assertSame( $expected, $return_val );
 	}
+
+	/**
+	 * Verifies that filter_widget handles parsed blocks arrays (output of parse_blocks)
+	 * and respects visibility rules without throwing errors.
+	 */
+	public function test_filter_widget_with_parsed_blocks_array() {
+		// Block with rule for "Display only when logged out" (Will pass during unit tests).
+		$block_content = '<!-- wp:paragraph {"conditions":{"action":"show","rules":[{"major":"loggedin","minor":"loggedout"}],"match_all":0}} -->'
+			. "\n" . '<p>Test Paragraph</p>'
+			. "\n" . '<!-- /wp:paragraph -->';
+		$parsed_blocks = parse_blocks( $block_content );
+		$block         = array( 'content' => $parsed_blocks );
+		$expected      = unserialize( serialize( $block ) );
+		$return_val    = Jetpack_Widget_Conditions::filter_widget( $block );
+		$this->assertSame( $expected, $return_val );
+
+		// Block with rule for "Display only when logged in" (Will fail during unit tests).
+		$block_content = '<!-- wp:paragraph {"conditions":{"action":"show","rules":[{"major":"loggedin","minor":"loggedin"}],"match_all":0}} -->'
+			. "\n" . '<p>Test Paragraph</p>'
+			. "\n" . '<!-- /wp:paragraph -->';
+		$parsed_blocks = parse_blocks( $block_content );
+		$block         = array( 'content' => $parsed_blocks );
+		$expected      = false;
+		$return_val    = Jetpack_Widget_Conditions::filter_widget( $block );
+		$this->assertSame( $expected, $return_val );
+	}
+
+	/**
+	 * Verifies that filter_widget safely bails and returns the instance when content
+	 * is an unknown array shape that cannot be normalized.
+	 */
+	public function test_filter_widget_with_unknown_array_shape() {
+		$block    = array( 'content' => array( 'foo' => 'bar' ) );
+		$expected = unserialize( serialize( $block ) );
+		$this->assertSame( $expected, Jetpack_Widget_Conditions::filter_widget( $block ) );
+	}
+
+	/**
+	 * Verifies that filter_widget safely returns the instance when content is an empty array.
+	 */
+	public function test_filter_widget_with_empty_array_content() {
+		$block    = array( 'content' => array() );
+		$expected = unserialize( serialize( $block ) );
+		$this->assertSame( $expected, Jetpack_Widget_Conditions::filter_widget( $block ) );
+	}
 }