Homie.prepareToSleep results in crash on ESP32

[qwandor]

Using the latest version from the develop branch, on an ESP32 with SSL enabled, I get the following crash a few seconds after calling Homie.prepareToSleep(), and never get a READY_TO_SLEEP event:

Offline message acknowledged. Disconnecting MQTT...
assertion "pbuf_free: p->ref > 0" failed: file "/home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/lwip/lwip/src/core/pbuf.c", line 765, function: pbuf_free

Backtrace: 0x4008d190:0x3ffd5720 0x4008d3c1:0x3ffd5740 0x401120c3:0x3ffd5760 0x4012b913:0x3ffd5790 0x401969c1:0x3ffd57b0 0x40196a99:0x3ffd5800 0x40196fd2:0x3ffd5820 0x400898a5:0x3ffd5850
#0 0x4008d190:0x3ffd5720 in invoke_abort at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/esp32/panic.c:707
#1 0x4008d3c1:0x3ffd5740 in abort at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/esp32/panic.c:707
#2 0x401120c3:0x3ffd5760 in __assert_func at /Users/ivan/e/newlib_xtensa-2.2.0-bin/newlib_xtensa-2.2.0/xtensa-esp32-elf/newlib/libc/stdlib/../../../.././newlib/libc/stdlib/assert.c:63 (discriminator 8)
#3 0x4012b913:0x3ffd5790 in pbuf_free at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/lwip/lwip/src/core/pbuf.c:1331
#4 0x401969c1:0x3ffd57b0 in AsyncClient::_recv(tcp_pcb*, pbuf*, signed char) at .pio/libdeps/m5stick-c/AsyncTCP/src/AsyncTCP.cpp:1246
#5 0x40196a99:0x3ffd5800 in AsyncClient::_s_recv(void*, tcp_pcb*, pbuf*, signed char) at .pio/libdeps/m5stick-c/AsyncTCP/src/AsyncTCP.cpp:1246
#6 0x40196fd2:0x3ffd5820 in _async_service_task(void*) at .pio/libdeps/m5stick-c/AsyncTCP/src/AsyncTCP.cpp:1246
(inlined by) _async_service_task at .pio/libdeps/m5stick-c/AsyncTCP/src/AsyncTCP.cpp:202
#7 0x400898a5:0x3ffd5850 in vPortTaskWrapper at /home/runner/work/esp32-arduino-lib-builder/esp32-arduino-lib-builder/esp-idf/components/freertos/port.c:355 (discriminator 1)

Rebooting...
ets Jun 8 2016 00:22:57

rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 188777542, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:2
load:0x3fff0018,len:4
load:0x3fff001c,len:1044
load:0x40078000,len:8896
load:0x40080400,len:5828
entry 0x400806ac

[qwandor]

This is on an M5Stick-C, in case it makes a difference.