From 38ade1742c46b2840ad23411b3105766bd32338c Mon Sep 17 00:00:00 2001
From: Andrew Moore <andrew@blakeslee.xyz>
Date: Sun, 9 Aug 2026 16:37:41 -0700
Subject: [PATCH] Merge nucleic/tidy-thistle-egret-5vjm into dev

---
 NUCLEIC_FORK.md                               |  1 +
 brush-builtins/src/dot.rs                     | 28 +++++++++++++++----
 .../tests/cases/compat/builtins/dot.yaml      | 10 +++++++
 3 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/NUCLEIC_FORK.md b/NUCLEIC_FORK.md
index 56acdc8..5660200 100644
--- a/NUCLEIC_FORK.md
+++ b/NUCLEIC_FORK.md
@@ -15,6 +15,7 @@ Every fork change is marked with a `// nash:` comment. Current patches:
 | `brush-core/src/expansion.rs` | corpus divergence D1: added `ExpansionPiece::LiteralText` — literal unquoted text is never field-split (bash splits only expansion results) but keeps glob characters active. Parameter-expansion substitutions (`${v:-word}` etc.) convert back to splittable at the expansion boundary; `ExpanderOptions.field_split_literal_text` lets data-string callers opt in. Upstream candidate. |
 | `brush-core/src/completion.rs` | `compgen -W` word list opts into `field_split_literal_text` (the -W string is data) |
 | `brush-shell/tests/cases/compat/ifs.yaml` | removed `known_failure` from 3 IFS tests the D1 fix repairs |
+| `brush-builtins/src/dot.rs` + `brush-shell/tests/cases/compat/builtins/dot.yaml` | the `.` / `source` builtin searches `PATH` for slashless operands when `sourcepath` is enabled, as Bash/POSIX require; fixes `git-subtree` sourcing `git-sh-setup` |
 | `brush-core/src/gate.rs` (new) + `lib.rs` | the `Gate` trait (docs/NASH.md §4.2): process-global, verdict-shaped hook; allow-all default so an unconfigured shell behaves exactly like upstream |
 | `brush-core/src/commands.rs` | `SimpleCommand::execute` split into gate wrapper + `execute_inner`: `on_exec` before dispatch (Deny short-circuits), completion correlated through all three spawn-result variants |
 | `brush-core/src/processes.rs` | `ChildProcess.gate_token` + `on_exit` reporting from `wait()`/`poll()` (128+signal for signal deaths) |
diff --git a/brush-builtins/src/dot.rs b/brush-builtins/src/dot.rs
index 7bf5a4b..a53e796 100644
--- a/brush-builtins/src/dot.rs
+++ b/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
     }
 }
diff --git a/brush-shell/tests/cases/compat/builtins/dot.yaml b/brush-shell/tests/cases/compat/builtins/dot.yaml
index a583e04..b606608 100644
--- a/brush-shell/tests/cases/compat/builtins/dot.yaml
+++ b/brush-shell/tests/cases/compat/builtins/dot.yaml
@@ -11,6 +11,16 @@ cases:
       . script.sh
       echo "var: ${var}"
 
+  - name: "Dot searches PATH for git setup scripts"
+    test_files:
+      - path: "git-core/git-sh-setup"
+        contents: |
+          require_work_tree() { echo "sourced git setup"; }
+    stdin: |
+      PATH="$PWD/git-core:$PATH"
+      . git-sh-setup
+      require_work_tree
+
   - name: "Basic source usage"
     test_files:
       - path: "script.sh"