Merge nucleic/tidy-thistle-egret-5vjm into dev

brush-builtins/src/dot.rs

@@ -1,4 +1,4 @@
-use std::path::Path;
+use std::path::{Path, PathBuf};
 
 use brush_core::builtins;
 use clap::Parser;
@@ -22,13 +22,29 @@ impl builtins::Command for DotCommand {
         context: brush_core::ExecutionContext<'_, SE>,
     ) -> Result<brush_core::ExecutionResult, Self::Error> {
         // TODO(dot): Handle trap inheritance.
+        // nash: POSIX requires `.` to search PATH when its operand has no slash.
+        // Git's `git-subtree` relies on this with `. git-sh-setup`; treating the
+        // operand as cwd-relative leaves `require_work_tree` undefined.
+        let script_path = Path::new(&self.script_path);
+        let resolved_path = if context.shell.options().source_builtin_searches_path
+            && !self.script_path.chars().any(std::path::is_separator)
+        {
+            context
+                .shell
+                .env_str("PATH")
+                .and_then(|path| {
+                    std::env::split_paths(path.as_ref())
+                        .map(|dir| dir.join(script_path))
+                        .find(|candidate| candidate.is_file())
+                })
+                .unwrap_or_else(|| PathBuf::from(script_path))
+        } else {
+            PathBuf::from(script_path)
+        };
+
         context
             .shell
-            .source_script(
-                Path::new(&self.script_path),
-                self.script_args.iter(),
-                &context.params,
-            )
+            .source_script(&resolved_path, self.script_args.iter(), &context.params)
             .await
     }
 }