Fix for how config works

[MrSurly]

Consider a Config field for a component is -bat_pwr,+ext_pwr,+dual_pwr,+kitchen_sink

Let's ignore the exclude (bat_pwr). This component is present in multiple variants; ext_pwr, dual_pwr, kitchen_sink

Given the current code below, and assuming we selected ext_pwr:

    result = True
    for opt in opts:
        #options that start with '-' are explicitly removed from certain configurations
        if opt.startswith('-') and opt[1:].lower() == self.prefs.pcbConfig.lower():
            result = False
            break
        if opt.startswith("+"):
            result = False
            if opt[1:].lower() == self.prefs.pcbConfig.lower():
                result = True

This means that the result will be False for this component because it loops through opts multiple times. The last opt is +kitchen_sink, but since it sets result to False, and the following if statement fails (because we're using ext_pwr), this component is not fitted.

Proposed change:

included = not bool(opts) #included by default if no options
excluded = False

config = self.prefs.pcbConfig.lower()
for opt in opts:
    #options that start with '-' are explicitly removed from certain configurations
    if opt.startswith('-') and opt[1:].lower() == config:
        excluded = True
        break
    if opt.startswith("+") and opt[1:].lower() == config:
        included = True
        break

result = included and not excluded

• included is set to True if opts is empty, else it's False
• Any hit on the iterate breaks, since pcbConfig is only a single value
• Edge cases where a config includes the same variant twice, then the first variant that matches will take precedence. Arguably, this should be an error condition.

[SchrodingersGat]

@MrSurly this makes sense, thanks for the contribution :)