Media: Ensure wp_read_image_metadata filter returns array for $iptc and $exif.

Makes the behavior of the filter lines up with its documentation.
Previously, both `$iptc` and `$exif` could return `false` when `exif_read_data()` or `iptcparse()` failed.

Now, if those functions do not return an array, the results are explicitly set to `array()`.

Props volodymyrkolesnykov, SergeyBiryukov, sabernhardt, sumitsingh, mikeschroder.
Fixes #54637.

git-svn-id: https://develop.svn.wordpress.org/trunk@53303 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/image.php

@@ -776,6 +776,10 @@ function wp_read_image_metadata( $file ) {
 				$iptc = @iptcparse( $info['APP13'] );
 			}
 
+			if ( ! is_array( $iptc ) ) {
+				$iptc = array();
+			}
+
 			// Headline, "A brief synopsis of the caption".
 			if ( ! empty( $iptc['2#105'][0] ) ) {
 				$meta['title'] = trim( $iptc['2#105'][0] );
@@ -845,6 +849,10 @@ function wp_read_image_metadata( $file ) {
 			$exif = @exif_read_data( $file );
 		}
 
+		if ( ! is_array( $exif ) ) {
+			$exif = array();
+		}
+
 		if ( ! empty( $exif['ImageDescription'] ) ) {
 			mbstring_binary_safe_encoding();
 			$description_length = strlen( $exif['ImageDescription'] );