Should there be a test for config.WorkingDir == "" to default it to C:\ for Windows as it's done from Linux above in L321?

I thought it make some sense to have "" value, assuming it has meaning "unspecified" to bypass it father and something later will know what exactly it means. In other words I wasn't sure if it is right place to do it. So should I add this test here?

What do you need to change the existing code? Seems like all that is new is the s.Process.Cwd = config.WorkingDir. Doesn't config.Cmd... expand properly to zero automatically by golang?

Seems the model is inconsistent already. We should likely be using replaceOrAppendEnvValues everywhere. But at a minimum I think yes we should be appending here too otherwise call order would really matter for env's.

hmm, when we use replaceOrAppendEnvValues, what should override what? s.Process.Env should override config.Env or opposite config.Env overrides s.Process.Env ? In other words it should be:
s.Process.Env = replaceOrAppendEnvValues(s.Process.Env, config.Env)
or
s.Process.Env = replaceOrAppendEnvValues(config.Env, s.Process.Env)
?

also should we check if current working directory was already set or override it no matter what?

cwd := config.WorkingDir
if cwd == "" {
   cwd = "/"
}
s.Process.Cwd = cwd

or

if s.Process.Cwd != "" {
  s.Process.Cwd = config.WorkingDir
}

more specifically, say we have image:

FROM ...
...
WORKDIR "/bin"

then we create container with options:

opts := []oci.SpecOpts{
  WithProcessCwd("/app"),
  WithImageConfig(image)
}

what should be current working directory for this container "/app" or "/bin"?

I added following changes:
WithImageConfigArgs will override env,args,cwd of all previous WithXxx calls.
env will be merged using replaceOrAppendEnvValues instead of append.
args,cwd will be just replaced

Should s.Process.Env be appended to ^ as done for Linux in L313?

Hard to answer for me actually, as I have arguments "for" and "against". So on one hand it was like this before but on other hand why do we have different behavior for linux and windows? Also why do we have different "merge"/"apply" behaviors, so all other parameters we replace/override, but for env we use "append" behavior, what are use cases to have this exception?