From f19567011f710e535632eeb1c7b36eb44b4fdad0 Mon Sep 17 00:00:00 2001
From: Martin von Zweigbergk <martinvonz@google.com>
Date: Thu, 9 May 2024 13:16:39 -0700
Subject: [PATCH] config: set `$LESS` and `$LESSCHARSET` even if `$PAGER` is
 set

Our current default for `ui.pager` is this:

```toml
ui.pager = { command = ["less"], env_default = { LESS = "-FRX", LESSCHARSET = "utf-8" } }
```

If the user has `$PAGER` set, we take that value and replace the above
table by a scalar set to the value from the environment variable. That
means that anyone who has set `$PAGER` to just `less` will lose both
the `-FRX` and the charset, making e.g. colored output from `jj`
result in escaped ANSI codes rendered by `less`. The lack of those
options might not matter for other tools they use so they might not
have realized that they wanted those options.

This patch attempts to improve the situation by setting the value from
`$PAGER` in `ui.pager.command` so the rest of the config is left
alone.

The default config will still be ignored if you set the scalar
`ui.pager` to e.g. `less`, since that overrides the table.

Closes #2926
---
 cli/src/config.rs | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/cli/src/config.rs b/cli/src/config.rs
index de7b5fe8ac..63ca5dab08 100644
--- a/cli/src/config.rs
+++ b/cli/src/config.rs
@@ -324,7 +324,18 @@ fn env_base() -> config::Config {
         builder = builder.set_override("ui.color", "never").unwrap();
     }
     if let Ok(value) = env::var("PAGER") {
-        builder = builder.set_override("ui.pager", value).unwrap();
+        builder = builder
+            .set_override(
+                "ui.pager.command",
+                config::Value::new(
+                    None,
+                    config::ValueKind::Array(vec![config::Value::new(
+                        None,
+                        config::ValueKind::String(value),
+                    )]),
+                ),
+            )
+            .unwrap();
     }
     if let Ok(value) = env::var("VISUAL") {
         builder = builder.set_override("ui.editor", value).unwrap();