Don't read git files when --no-gitconfig is given + unused variables (#1728)

* Fix unused variables

* Don't read git files when --no-gitconfig is given

Despite starting delta with `--no-gitconfig`, strace still shows
that `.git/config` etc. files are accessed. By no longer doing
that it is very clear that no config options are read from there.

8 files changed, 20 insertions, 31 deletions

diff --git a/src/cli.rs b/src/cli.rs
index 723ea42c..a18f11e4 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -1159,18 +1159,19 @@ pub enum DetectDarkLight {
 }
 
 impl Opt {
-    pub fn from_args_and_git_config(
-        env: DeltaEnv,
-        git_config: Option<GitConfig>,
-        assets: HighlightingAssets,
-    ) -> Self {
-        let mut final_config = git_config;
+    pub fn from_args_and_git_config(env: &DeltaEnv, assets: HighlightingAssets) -> Self {
         let matches = Self::command().get_matches();
 
+        let mut final_config = if *matches.get_one::<bool>("no_gitconfig").unwrap_or(&false) {
+            None
+        } else {
+            GitConfig::try_create(env)
+        };
+
         if let Some(path) = matches.get_one::<String>("config") {
             if !path.is_empty() {
                 let path = Path::new(path);
-                final_config = Some(GitConfig::from_path(&env, path, true));
+                final_config = Some(GitConfig::from_path(env, path, true));
             }
         }
 
@@ -1178,7 +1179,7 @@ impl Opt {
     }
 
     pub fn from_iter_and_git_config<I>(
-        env: DeltaEnv,
+        env: &DeltaEnv,
         iter: I,
         git_config: Option<GitConfig>,
     ) -> Self
@@ -1196,14 +1197,14 @@ impl Opt {
     }
 
     fn from_clap_and_git_config(
-        env: DeltaEnv,
+        env: &DeltaEnv,
         arg_matches: clap::ArgMatches,
         mut git_config: Option<GitConfig>,
         assets: HighlightingAssets,
     ) -> Self {
         let mut opt = Opt::from_arg_matches(&arg_matches)
             .unwrap_or_else(|_| delta_unreachable("Opt::from_arg_matches failed"));
-        opt.env = env;
+        opt.env = env.clone();
         options::set::set_options(&mut opt, &mut git_config, &arg_matches, assets);
         opt.git_config = git_config;
         opt
diff --git a/src/config.rs b/src/config.rs
index 76789289..5247cdf8 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -125,7 +125,6 @@ pub struct Config {
     pub show_themes: bool,
     pub side_by_side_data: side_by_side::SideBySideData,
     pub side_by_side: bool,
-    pub syntax_dummy_theme: SyntaxTheme,
     pub syntax_set: SyntaxSet,
     pub syntax_theme: Option<SyntaxTheme>,
     pub tab_cfg: utils::tabs::TabCfg,
@@ -417,7 +416,6 @@ impl From<cli::Opt> for Config {
             side_by_side: opt.side_by_side && !handlers::hunk::is_word_diff(),
             side_by_side_data,
             styles_map,
-            syntax_dummy_theme: SyntaxTheme::default(),
             syntax_set: opt.computed.syntax_set,
             syntax_theme: opt.computed.syntax_theme,
             tab_cfg: utils::tabs::TabCfg::new(opt.tab_width),
diff --git a/src/env.rs b/src/env.rs
index 8c169bcc..49c7b212 100644
--- a/src/env.rs
+++ b/src/env.rs
@@ -77,6 +77,8 @@ pub mod tests {
         env::set_var("DELTA_FEATURES", feature);
         let env = DeltaEnv::init();
         assert_eq!(env.features, Some(feature.into()));
+        // otherwise `current_dir` is not used in the test cfg:
+        assert_eq!(env.current_dir, env::current_dir().ok());
     }
 
     #[test]
diff --git a/src/features/mod.rs b/src/features/mod.rs
index dfc3582d..133cea42 100644
--- a/src/features/mod.rs
+++ b/src/features/mod.rs
@@ -103,7 +103,7 @@ pub mod tests {
         let builtin_features = make_builtin_features();
         let mut args = vec!["delta".to_string()];
         args.extend(builtin_features.keys().map(|s| format!("--{s}")));
-        let opt = cli::Opt::from_iter_and_git_config(DeltaEnv::default(), args, None);
+        let opt = cli::Opt::from_iter_and_git_config(&DeltaEnv::default(), args, None);
         let features: HashSet<&str> = opt
             .features
             .as_deref()
diff --git a/src/main.rs b/src/main.rs
index 67ea0ca3..925e7dc4 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -76,11 +76,7 @@ fn main() -> std::io::Result<()> {
 fn run_app() -> std::io::Result<i32> {
     let assets = utils::bat::assets::load_highlighting_assets();
     let env = env::DeltaEnv::init();
-    let opt = cli::Opt::from_args_and_git_config(
-        env.clone(),
-        git_config::GitConfig::try_create(&env),
-        assets,
-    );
+    let opt = cli::Opt::from_args_and_git_config(&env, assets);
 
     let subcommand_result = if let Some(shell) = opt.generate_completion {
         Some(subcommands::generate_completion::generate_completion_file(
diff --git a/src/subcommands/show_colors.rs b/src/subcommands/show_colors.rs
index 2898dd97..9d0428c7 100644
--- a/src/subcommands/show_colors.rs
+++ b/src/subcommands/show_colors.rs
@@ -4,7 +4,6 @@ use crate::colors;
 use crate::config;
 use crate::delta;
 use crate::env::DeltaEnv;
-use crate::git_config;
 use crate::paint;
 use crate::paint::BgShouldFill;
 use crate::style;
@@ -16,11 +15,7 @@ pub fn show_colors() -> std::io::Result<()> {
 
     let assets = utils::bat::assets::load_highlighting_assets();
     let env = DeltaEnv::default();
-    let opt = cli::Opt::from_args_and_git_config(
-        env.clone(),
-        git_config::GitConfig::try_create(&env),
-        assets,
-    );
+    let opt = cli::Opt::from_args_and_git_config(&env, assets);
     let config = config::Config::from(opt);
 
     let mut output_type =
diff --git a/src/subcommands/show_themes.rs b/src/subcommands/show_themes.rs
index 52c92386..86cae34d 100644
--- a/src/subcommands/show_themes.rs
+++ b/src/subcommands/show_themes.rs
@@ -36,7 +36,7 @@ pub fn show_themes(dark: bool, light: bool, computed_theme_is_light: bool) -> st
 
     let git_config = git_config::GitConfig::try_create(&env);
     let opt = cli::Opt::from_iter_and_git_config(
-        env.clone(),
+        &env,
         &["delta", "--navigate", "--show-themes"],
         git_config,
     );
@@ -47,11 +47,8 @@ pub fn show_themes(dark: bool, light: bool, computed_theme_is_light: bool) -> st
 
     for theme in &themes {
         let git_config = git_config::GitConfig::try_create(&env);
-        let opt = cli::Opt::from_iter_and_git_config(
-            env.clone(),
-            &["delta", "--features", theme],
-            git_config,
-        );
+        let opt =
+            cli::Opt::from_iter_and_git_config(&env, &["delta", "--features", theme], git_config);
         let is_dark_theme = opt.dark;
         let is_light_theme = opt.light;
         let config = config::Config::from(opt);
diff --git a/src/tests/integration_test_utils.rs b/src/tests/integration_test_utils.rs
index 764be5d2..09e445e9 100644
--- a/src/tests/integration_test_utils.rs
+++ b/src/tests/integration_test_utils.rs
@@ -66,7 +66,7 @@ fn _make_options_from_args_and_git_config(
             None
         }
     };
-    cli::Opt::from_iter_and_git_config(env, args, git_config)
+    cli::Opt::from_iter_and_git_config(&env, args, git_config)
 }
 
 pub fn make_options_from_args(args: &[&str]) -> cli::Opt {