qstrs behave differently between REPL and frozen modules -- demonstrated by network_wlan.c bugs.

[envirocoder]

The following code doesn't work in _boot.py but does when run from the repl.

import network
ap = network.WLAN(network.AP_IF)
print(ap.config('mac'))
print(ap.config('dhcp_hostname'))

resulting in the error:

Traceback (most recent call last):
  File "_boot.py", line 4, in <module>
ValueError: unknown config param

I think this is related to string interning. Looking in corresponding generated frozen_content.c:

    0x16, MP_QSTR_ap & 0xff, MP_QSTR_ap >> 8, 
    0x11, MP_QSTR_print & 0xff, MP_QSTR_print >> 8, 
    0x11, MP_QSTR_ap & 0xff, MP_QSTR_ap >> 8, 
    0x14, MP_QSTR_config & 0xff, MP_QSTR_config >> 8, 
    0x10, MP_QSTR_mac & 0xff, MP_QSTR_mac >> 8, 
    0x36, 0x01, 
    0x34, 0x01, 
    0x59, 
    0x11, MP_QSTR_print & 0xff, MP_QSTR_print >> 8, 
    0x11, MP_QSTR_ap & 0xff, MP_QSTR_ap >> 8, 
    0x14, MP_QSTR_config & 0xff, MP_QSTR_config >> 8, 
    0x23, 0x00, 
    0x36, 0x01, 
    0x34, 0x01, 
    0x59, 
    0x51, 
    0x63, 
};
STATIC const mp_obj_str_t const_obj__boot__lt_module_gt__0 = {{&mp_type_str}, 18850, 13, (const byte*)"\x64\x68\x63\x70\x5f\x68\x6f\x73\x74\x6e\x61\x6d\x65"};

It appears MP_QSTR_mac is treated differently than \x64\x68\x63\x70\x5f\x68\x6f\x73\x74\x6e\x61\x6d\x65 (dhcp_hostname).

I think this means that the reference to case QS(MP_QSTR_dhcp_hostname): on

micropython/ports/esp32/network_wlan.c

Line 527 in de7e3cd

case QS(MP_QSTR_dhcp_hostname): {

doesn't match.

I found this when adding my own code to the network_wlan -- initially I thought it was my bug (see https://forum.micropython.org/viewtopic.php?f=3&t=11519) but I now think its something wider.

While, as was pointed out to me, only literals shorter than length 10 are supposed to be QSTRs, in this behaviour they're looked up from strings on the REPL but not from frozen.

[dpgeorge]

Thanks for the report. This was previously an issue on esp8266 and was fixed on that port, see #3442

[dpgeorge]

See #8077 for a fix.

[dpgeorge]

Fixed by 5adb1fa