Description:
------------
When the php run the code which invoke HTMLPurifier, The php-fpm or php cli processes CPU usage 100%, The php-fpm will occur Nginx response 504 (time out). When I run `php HTMLPurifier.standalone.php`, the process CPU usage to 100% and can not be exit normally. I need force kill it.

The problem occur php 7.1.5/7.1.4 (I tested versions on my virtual machine). Also I tested php 7.0.19, No problem with it.


I compiled the official released version:

./configure --enable-debug
make

Changed opcache.enable_cli=1 in the php.ini-development, and loaded opcache.so file from php-src/modules/ directory.

Run the script

./sapi/cli/php -c ~/HTMLPurifier.standalone.php


The gdb backtrace 

---- gdb backtrace ----

(gdb) bt
#0  0x00007ffff63b2495 in raise (sig=6)
    at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1  0x00007ffff63b3c75 in abort () at abort.c:92
#2  0x00007ffff63ab60e in __assert_fail_base (
    fmt=<value optimized out>, assertion=0x7fffef950328 "0",
    file=0x7fffef950268 "/root/download/php-7.1.5/ext/opcache/Optimizer/zend_inference.c", line=<value optimized out>,
    function=<value optimized out>) at assert.c:96
#3  0x00007ffff63ab6d0 in __assert_fail (assertion=0x7fffef950328 "0",
    file=0x7fffef950268 "/root/download/php-7.1.5/ext/opcache/Optimizer/zend_inference.c", line=1902,
    function=0x7fffef950cb0 "check_type_narrowing") at assert.c:105
#4  0x00007fffef92a210 in check_type_narrowing (
    op_array=0x7fffe74f06f8, ssa=0x7fffe7216700,
    worklist=0x7fffffffa700, var=37, old_type=402653444,
    new_type=411040760)
    at /root/download/php-7.1.5/ext/opcache/Optimizer/zend_inference.c:1902
#5  0x00007fffef939041 in zend_update_type_info (
    op_array=0x7fffe74f06f8, ssa=0x7fffe7216700, script=0x7ffff5a7a000,
    worklist=0x7fffffffa700, i=44)
    at /root/download/php-7.1.5/ext/opcache/Optimizer/zend_inference.c:3113
#6  0x00007fffef93b810 in zend_infer_types_ex (op_array=0x7fffe74f06f8,
    script=0x7ffff5a7a000, ssa=0x7fffe7216700, worklist=0x7fffffffa700)
    at /root/download/php-7.1.5/ext/opcache/Optimizer/zend_inference.c:3332
#7  0x00007fffef93d743 in zend_infer_types (op_array=0x7fffe74f06f8,
    script=0x7ffff5a7a000, ssa=0x7fffe7216700)
    at /root/download/php-7.1.5/ext/opcache/Optimizer/zend_inference.c:3811
#8  0x00007fffef93dbae in zend_ssa_inference (arena=0x7fffffffa860,
    op_array=0x7fffe74f06f8, script=0x7ffff5a7a000, ssa=0x7fffe7216700)
    at /root/download/php-7.1.5/ext/opcache/Optimizer/zend_inference.c:3876
#9  0x00007fffef914839 in zend_dfa_analyze_op_array (
---Type <return> to continue, or q <return> to quit---
    op_array=0x7fffe74f06f8, ctx=0x7fffffffa860, ssa=0x7fffe7216700,
    flags=0x7fffe72166fc)
    at /root/download/php-7.1.5/ext/opcache/Optimizer/dfa_pass.c:106
#10 0x00007fffef8feae5 in zend_optimize_script (script=0x7ffff5a7a000,
    optimization_level=2147467263, debug_level=0)
    at /root/download/php-7.1.5/ext/opcache/Optimizer/zend_optimizer.c:993
#11 0x00007fffef8dab79 in cache_script_in_shared_memory (
    new_persistent_script=0x7ffff5a7a000,
    key=0x1126d90 "/root/HTMLPurifier.standalone.php", key_length=33,
    from_shared_memory=0x7fffffffaaa0)
    at /root/download/php-7.1.5/ext/opcache/ZendAccelerator.c:1273
#12 0x00007fffef8dc5ad in persistent_compile_file (
    file_handle=0x7fffffffe030, type=8)
    at /root/download/php-7.1.5/ext/opcache/ZendAccelerator.c:1865
#13 0x000000000087b325 in zend_execute_scripts (type=8, retval=0x0,
    file_count=3) at /root/download/php-7.1.5/Zend/zend.c:1470
#14 0x00000000007e54a6 in php_execute_script (
    primary_file=0x7fffffffe030)
    at /root/download/php-7.1.5/main/main.c:2537
#15 0x000000000096f87a in do_cli (argc=4, argv=0x1126cf0)
    at /root/download/php-7.1.5/sapi/cli/php_cli.c:993
#16 0x00000000009707b9 in main (argc=4, argv=0x1126cf0)
    at /root/download/php-7.1.5/sapi/cli/php_cli.c:1381

Test script:
---------------
https://gist.github.com/lkebin/e25594cfd493e984054686a7cd2ec4b8

Expected result:
----------------
From php cli to run the test script should be empty output and exit 0