Can't send a data value of 0 via IR module.

[crankyoldgit]

Can't send a data value of 0 via the IR module.

The IR subsystem fails to send a message when the data payload is 0 (zero).

To Reproduce
Send a MQTT message to the irsend module.
e.g.
topic: "cmnd/SONOFF_DEVICE/irsend"
payload: '{"Protocol": "SAMSUNG","Bits":32,"data":0}'
Expected behavior
A Samsung 32bit message with a value of 0 should be transmitted.
e.g. A call of irsend->sendSAMSUNG(0, 32); should be made. It doesn't.

Screenshots
N/A

Additional context
I think the bug is here:
https://github.com/arendst/Sonoff-Tasmota/blob/development/sonoff/xdrv_02_irremote.ino#L301

        data = strtoul(root[UpperCase_P(parm_uc, PSTR(D_JSON_IR_DATA))], NULL, 0);
        if (protocol && bits && data) {

When data is 0, it evaluates as False in the above if statement.

Most simple fix is to change:

        if (protocol && bits && data) {

to:

        if (protocol && bits) {

Technically a more correct fix is to check if you had a parsing error (you can't do that with strtoul()) and to NOT assume a return value of 0 from strtoul() is a parse error, a str of "0" is valid and a potential value, and a real result of strtoul().

TL;DR: When strtoul() returns zero, it isn't always a failure to convert.

Workarounds:
Specify a value that has the lower bits as zero. e.g. 2^32 which has the lower 32 bits as 0, but the entire value is != 0. e.g. 0b100000000000000000000000000000000

MQTT example of the workaround:

payload: '{"Protocol": "SAMSUNG","Bits":32,"data":0}'  // does nothing

payload: '{"Protocol": "SAMSUNG","Bits":32,"data":4294967296}'  // works (sends a 0 IR message)

Ref:
crankyoldgit/IRremoteESP8266#447 (comment)

[arendst]

I agree. I went for your simple fix and PR

Another solution would be to test for any string length before using strtoul