QTextDocument::setHtml() consuming more than 25 GB of memory

1. Build the attached project.
   No sanitizers needed.
2. Run the resulting program passing in the attached input file, e.g.:

   ./report 51266.html
   

   The program will allocate more than 25GB of memory and keep growing. If the file is broken, could QTextDocument notice that and exit earlier?

Google's oss-fuzz found this as issue 51266.