Fixes https://gitea.com/gitea/tea/issues/1053
## What
tea hangs forever on Windows when it is started by something that owns a console but redirects
tea's stdio: a Windows service, a CI runner, an automation harness. Every command is affected,
`tea --version` included.
## Root cause
`modules/theme` imported `charm.land/lipgloss/v2/compat` for one struct type,
`compat.AdaptiveColor`. But compat detects the terminal background from package-level vars:
```go
var (
HasDarkBackground = lipgloss.HasDarkBackground(os.Stdin, os.Stdout)
Profile = colorprofile.Detect(os.Stdout, os.Environ())
)
```
Go initialises every package in the import graph before `main()` runs, and every file in package
`cmd` imports `modules/context`, which imports `modules/theme`. So tea queried the terminal on
every invocation, before urfave/cli had even looked at the arguments — which is why `--version`
hung.
On Windows that query opens `CONIN$`/`CONOUT$` and asks the console directly instead of giving up
when stdio is redirected, then waits for a reply that never comes. The read has a 2 second timeout,
but it does not fire, because the cancel it relies on is a no-op for that handle. Full trace in the
issue.
## Changes
- `modules/theme/theme.go` — drop the `compat` import and use `lipgloss.LightDark`, a plain
function that touches no terminal. `TeaTheme.Theme` is already handed the `isDark` it needs.
This also fixes a bug hiding in plain sight: `compat.AdaptiveColor` resolves against a
process-wide value detected at init, so the title color ignored the `isDark` argument huh passed
in. `Theme(true)` and `Theme(false)` returned the same color.
- `modules/theme/background.go` — new `HasDarkBackground()` helper that only asks the terminal when
stdin and stdout are both terminals, and otherwise assumes dark, which is the default lipgloss
itself falls back to. This is the same rule lipgloss already applies on Unix.
- `modules/interact/print.go` — `printTitleAndContent` called
`lipgloss.HasDarkBackground(os.Stdin, os.Stdout)` directly, so it hit the same wait on the
interactive paths, `tea login add` among them. It now goes through the helper.
## Why fix this in tea
The underlying bug is upstream and I have opened PRs for both halves of it: https://github.com/charmbracelet/ultraviolet/pull/138 and
https://github.com/charmbracelet/lipgloss/pull/713. But it is not fixed in any released version — lipgloss v2.0.5 is byte-identical to
v2.0.4 in the relevant files — so upgrading dependencies does not help, and tea would stay broken on
Windows until Charm cuts a release and tea bumps `go.mod`.
Separately, these changes stand on their own. tea should not query the terminal in order to print a
version string, whatever upstream does.
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Willem Kokke <mail@willem.net>
Willem Kokke