jw.pkg.lib.util.get_profile_env(): add -> keep

Replace the boolean parameter "add" with the richer "keep":

  - False            -> Don't keep anything
  - True             -> Keep what's in the current environment
  - List of strings  -> Keep those variables

Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/lib/util.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-from typing import Sequence
+from typing import Sequence, Iterable
 
 import os, sys, subprocess, json, time, asyncio
 
@@ -299,10 +299,28 @@ async def get_password(args: Namespace|None=None, url: str|None=None, askpass_en
             return parsed.password
     return await run_askpass(askpass_env, AskpassKey.Password)
 
-async def get_profile_env(throw: bool=True, add=False) -> dict[str, str]: # export
+async def get_profile_env(throw: bool=True, keep: Iterable[str]|bool=False) -> dict[str, str]: # export
-    env: dict[str,str]|None = None if add else {}
+    """
-    # Run bash, source /etc/profile, then print environment as NUL-separated key=value pairs
+    Get a fresh environment from /etc/profile
-    cmd = ['/bin/bash', '-lc', 'unset PROFILEREAD; source /etc/profile >/dev/null 2>&1; env -0']
+
+    Args:
+        keep:
+          - False            -> Don't keep anything
+          - True             -> Keep what's in the current environment
+          - List of strings  -> Keep those variables
+
+    Returns:
+        Dictionary with fresh environment
+    """
+    env: dict[str,str]|None = None
+    if keep == False or isinstance(keep, Iterable):
+        env = {
+            'HOME': os.environ.get('HOME', '/'),
+            'USER': os.environ.get('USER', ''),
+            'PATH': '/usr/bin:/bin',
+        }
+    # Run bash as a login shell, which sources /etc/profile, then print environment as NUL-separated key=value pairs
+    cmd = ['/usr/bin/env', '-i', '/bin/bash', '-lc', 'env -0']
     stdout, stderr = await run_cmd(*cmd, throw=throw, output_encoding="bytes", verbose=True, env=env)
     ret: dict[str, str] = {}
     for entry in stdout.split(b"\0"):
@@ -310,4 +328,9 @@ async def get_profile_env(throw: bool=True, add=False) -> dict[str, str]: # expo
             continue
         key, val = entry.split(b"=", 1)
         ret[key.decode()] = val.decode()
+    if isinstance(keep, Iterable):
+        for key in keep:
+            val = os.getenv(key)
+            if val is not None:
+                ret[key] = val
     return ret