Changeset 62029

Timestamp:

03/14/2026 11:54:43 PM (8 weeks ago)

Author:

SergeyBiryukov

Message:

Media: Correct parsing AVIF files with empty iref box on older PHP versions.

An empty iref box is pointless but is allowed by the specification. This commit imports an upstream fix from libavifinfo.

Follow-up to [57524], [58049].

Props yguyon.
Fixes #64669.

File:

• trunk/src/wp-includes/class-avif-info.php (modified) (8 diffs)

trunk/src/wp-includes/class-avif-info.php

@@ -10 +10 @@
  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
  *
- * Note: this class is from libavifinfo - https://aomedia.googlesource.com/libavifinfo/+/refs/heads/main/avifinfo.php at f509487.
+ * Note: this class is from libavifinfo - https://aomedia.googlesource.com/libavifinfo/+/refs/heads/main/avifinfo.php at 2b924de.
  * It is used as a fallback to parse AVIF files when the server doesn't support AVIF,
  * primarily to identify the width and height of the image.
@@ -110 +110 @@
   public $primary_item_features = array( // Deduced from the data below.
     'width'        => UNDEFINED, // In number of pixels.
-    'height'       => UNDEFINED, // Ignores mirror and rotation.
+    'height'       => UNDEFINED, // Ignores crop and rotation.
     'bit_depth'    => UNDEFINED, // Likely 8, 10 or 12 bits per channel per pixel.
     'num_channels' => UNDEFINED  // Likely 1, 2, 3 or 4 channels:
@@ -257 +257 @@
       $this->size = read_big_endian( substr( $data, 4, 4 ), 4 );
     } else if ( $this->size == 0 ) {
+      // ISO/IEC 14496-12 4.2.2:
+      //   if size is 0, then this box shall be in a top-level box
+      //   (i.e. not contained in another box)
+      // Unfortunately the presence of a parent box is unknown here.
       $this->size = $num_remaining_bytes;
     }
@@ -265 +269 @@
       return INVALID;
     }
+
+    // 16 bytes of usertype should be read here if the box type is 'uuid'.
+    // 'uuid' boxes are skipped so usertype is part of the skipped body.
 
     $has_fullbox_header = $this->type == 'meta' || $this->type == 'pitm' ||
@@ -303 +310 @@
       // Instead of considering this file as invalid, skip unparsable boxes.
       if ( !$is_parsable ) {
-        $this->type = 'unknownversion';
+        $this->type = 'skip'; // FreeSpaceBox. To be ignored by readers.
       }
     }
@@ -484 +491 @@
    * Parses an "iprp" box.
    *
-   * The "ipco" box contain the properties which are linked to items by the "ipma" box.
+   * The "ipco" box contains the properties which are linked to items by the "ipma" box.
    *
    * @param stream  $handle              The resource the box will be parsed from.
@@ -597 +604 @@
    */
   private function parse_iref( $num_remaining_bytes ) {
-    do {
+    while ( $num_remaining_bytes > 0 ) {
       $box    = new Box();
       $status = $box->parse( $this->handle, $this->num_parsed_boxes, $num_remaining_bytes );
@@ -657 +664 @@
       }
       $num_remaining_bytes -= $box->size;
-    } while ( $num_remaining_bytes > 0 );
+    }
     return NOT_FOUND;
   }