Canon EOS R5 CR3 pegs cpu at 100% with no GUI, #5882

rtengine/canon_cr3_decoder.cc

@@ -602,7 +602,9 @@ int DCraw::parseCR3(
                             relpos_inBox += lTag;
                         }
                     }
-
+                    if (!szItem) {
+                        goto fin;
+                    }
                     relpos_inDir += szItem;
                 }