Allow empty iref boxes Use a while loop instead of a do-while loop in C ParseIref(). Use a while loop instead of a do-while loop in PHP parse_iref(). There is already a while loop in Rust parse_iref(), likely because there is no do-while in Rust. See https://aomedia.g-issues.chromium.org/issues/466109759. Change-Id: Ia400a59ee3f90211226ba431a006f8aea3241f77

diff --git a/avifinfo.c b/avifinfo.c
index 5d7ec78..f8f7a04 100644
--- a/avifinfo.c
+++ b/avifinfo.c

@@ -620,7 +620,7 @@
                                         AvifInfoInternalFeatures* features) {
   features->iref_parsed = 1;
 
-  do {
+  while (num_remaining_bytes > 0) {
     AvifInfoInternalBox box;
     AVIFINFO_CHECK_FOUND(AvifInfoInternalParseBox(
         nesting_level, stream, num_remaining_bytes, num_parsed_boxes, &box));
@@ -672,7 +672,7 @@
       AVIFINFO_CHECK_FOUND(AvifInfoInternalSkip(stream, box.content_size));
     }
     num_remaining_bytes -= box.size;
-  } while (num_remaining_bytes > 0);
+  }
   AVIFINFO_RETURN(kNotFound);
 }
 

diff --git a/avifinfo.php b/avifinfo.php
index dfb67c3..228df83 100644
--- a/avifinfo.php
+++ b/avifinfo.php

@@ -597,7 +597,7 @@
    * @return Status                      FOUND on success or an error on failure.
    */
   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 );
       if ( $status != FOUND ) {
@@ -657,7 +657,7 @@
         }
       }
       $num_remaining_bytes -= $box->size;
-    } while ( $num_remaining_bytes > 0 );
+    }
     return NOT_FOUND;
   }