[olemke]

Summary

Constructing a Workspace used to initialize its variables with a plain copy of the global defaults map. Since Wsv stores its value through a std::shared_ptr, that copy shared the underlying value objects between every workspace and the global defaults, so a method writing its out variable in place silently corrupted the same variable in all other workspaces — including workspaces created later. This branch deep-copies each default variable in the Workspace constructor and adds a regression test that pins the behavior in place.

Changes

• src/workspace_class.h: The Workspace constructor now initializes its variable map by deep-copying each global default with Wsv::copied() (per-type copy dispatch) instead of copying the map itself, so every workspace owns independent value objects and writes to out variables stay local to that workspace.
• tests/python/workspaces-do-not-share-defaults.py: New regression test that calls jac_targetsAddTemperature() on one workspace and asserts that a second workspace, and one constructed only after the call, are unaffected. It fails on the base commit and passes with the fix.

Reproduction

Standalone script demonstrating the bug:

"""Minimal repro: Workspace instances sharing variable payloads."""

import pyarts3 as pa

a = pa.Workspace()
b = pa.Workspace()

before = b.jac_targets.target_count()
a.jac_targetsAddTemperature()  # writes the `out` variable `jac_targets` of `a`
after = b.jac_targets.target_count()

print(f"b.jac_targets.target_count(): {before} -> {after}")
if after != before:
    raise SystemExit("BUG: calling a method on `a` corrupted `b`")
print("OK: the two workspaces are independent")

Output on the base commit (bug):

$ python3 wsv_sharing_repro.py
b.jac_targets.target_count(): 0 -> 1
BUG: calling a method on `a` corrupted `b`
exit code: 1

Expected output with this branch (fix):

$ python3 wsv_sharing_repro.py
b.jac_targets.target_count(): 0 -> 0
OK: the two workspaces are independent
exit code: 0

The corruption also affected workspaces created after the method call, because the global defaults themselves were mutated; tests/python/workspaces-do-not-share-defaults.py covers that case as well.

[riclarsson]

Please merge. Good find.