fix(runtime/ops): use argv[0] as exe-name if present in op_exec_path()

[jhheider]

Signed-off-by: Jacob Heider [email protected]

fixes #17464

should be fairly non-invasive (given it falls back to original code), but it could break some existing usages which might rely on the current (platform-inconsistent) behavior.

[CLAassistant]

All committers have signed the CLA.

[jhheider]

Ok, this passes, and unfortunately we can't use PathBuf::canonicalize(), since it follows symlinks. So, using the URL module will have to remain to canonicalize the string only. But this does use argv[0] if present as exe_name, and joins it to cwd if it's relative (say, './foo').

The major risk here is changing behavior someone might be relying on. On linux, symlinks resolve to their target instead of themselves. The upside is that it will behave the same across platforms, now.

[dsherret]

I think this will break if a user does Deno.chdir before calling this function. I wonder if we should follow Rust and leave this up to users to do? I'm not sure what's best.

[jhheider]

Hm. That's a valid concern. I'll take a look at the execution environment and see if we can detect that.

Obviously, continuing to do what Rust does is one type of expectable behavior. It's unfortunate that different kernels do this differently. So, I'm torn between it's surprising because it's different from Rust or it's surprising because of environmental inconsistencies.

Obviously, we could use canonicalize() and always resolve the symlinks, but that feels like the worst version.

[jhheider]

use std::env;

fn main() {
  println!("{}", env::current_dir().unwrap().to_str().unwrap());
  env::set_current_dir("..").unwrap();
  println!("{}", env::current_dir().unwrap().to_str().unwrap());
}

Obviously does what you'd expect: "/Users/jacob\n/Users". And given that Deno.chdir() calls ops_chdir() > set_current_dir(), we can assume that your case will do that. So, a proper (full) solution would be to compute the value from argv[0] at invocation time, and cache it for the duration.

[jhheider]

Other options could include skipping it for relative executions paths, or passing those out instead of resolving to absolute paths.