handle config.channel default for tarballs

Signed-off-by: onur-ozkan <work@onurozkan.dev>

Author: onur-ozkan

Diff for: src/bootstrap/src/core/config/config.rs

@@ -1540,9 +1540,6 @@ impl Config {
             }
         }
 
-        let file_content = t!(fs::read_to_string(config.src.join("src/ci/channel")));
-        let ci_channel = file_content.trim_end();
-
         // Give a hard error if `--config` or `RUST_BOOTSTRAP_CONFIG` are set to a missing path,
         // but not if `bootstrap.toml` hasn't been created.
         let mut toml = if !using_default_path || toml_path.exists() {
@@ -1847,16 +1844,20 @@ impl Config {
         let mut lld_enabled = None;
         let mut std_features = None;
 
+        let file_content = t!(fs::read_to_string(config.src.join("src/ci/channel")));
+        let ci_channel = file_content.trim_end();
+
         let is_user_configured_rust_channel =
-            if let Some(channel) = toml.rust.as_ref().and_then(|r| r.channel.clone()) {
-                if channel == "auto-detect" {
+            match toml.rust.as_ref().and_then(|r| r.channel.clone()) {
+                Some(channel) if channel == "auto-detect" => {
                     config.channel = ci_channel.into();
-                } else {
+                    true
+                }
+                Some(channel) => {
                     config.channel = channel;
+                    true
                 }
-                true
-            } else {
-                false
+                None => false,
             };
 
         let default = config.channel == "dev";
@@ -1882,6 +1883,10 @@ impl Config {
                 && config.src.join(".cargo/config.toml").exists(),
         );
 
+        if !is_user_configured_rust_channel && config.rust_info.is_from_tarball() {
+            config.channel = ci_channel.into();
+        }
+
         if let Some(rust) = toml.rust {
             let Rust {
                 optimize: optimize_toml,
@@ -2085,8 +2090,6 @@ impl Config {
 
                 config.channel = channel;
             }
-        } else if config.rust_info.is_from_tarball() && !is_user_configured_rust_channel {
-            ci_channel.clone_into(&mut config.channel);
         }
 
         if let Some(llvm) = toml.llvm {