copy current exe to CODEX_HOME/.sandbox-bin for apply_patch (#13669)

We do this for codex-command-runner.exe as well for the same reason.
Windows sandbox users cannot execute binaries in the WindowsApp/
installed directory for the Codex App. This causes apply-patch to fail
because it tries to execute codex.exe as the sandbox user.

codex-rs/core/src/tools/runtimes/apply_patch.rs

@@ -46,13 +46,23 @@ impl ApplyPatchRuntime {
         Self
     }
 
-    fn build_command_spec(req: &ApplyPatchRequest) -> Result<CommandSpec, ToolError> {
-        use std::env;
+    fn build_command_spec(
+        req: &ApplyPatchRequest,
+        _codex_home: &std::path::Path,
+    ) -> Result<CommandSpec, ToolError> {
         let exe = if let Some(path) = &req.codex_exe {
             path.clone()
         } else {
-            env::current_exe()
-                .map_err(|e| ToolError::Rejected(format!("failed to determine codex exe: {e}")))?
+            #[cfg(target_os = "windows")]
+            {
+                codex_windows_sandbox::resolve_current_exe_for_launch(_codex_home, "codex.exe")
+            }
+            #[cfg(not(target_os = "windows"))]
+            {
+                std::env::current_exe().map_err(|e| {
+                    ToolError::Rejected(format!("failed to determine codex exe: {e}"))
+                })?
+            }
         };
         let program = exe.to_string_lossy().to_string();
         Ok(CommandSpec {
@@ -159,7 +169,7 @@ impl ToolRuntime<ApplyPatchRequest, ExecToolCallOutput> for ApplyPatchRuntime {
         attempt: &SandboxAttempt<'_>,
         ctx: &ToolCtx,
     ) -> Result<ExecToolCallOutput, ToolError> {
-        let spec = Self::build_command_spec(req)?;
+        let spec = Self::build_command_spec(req, &ctx.turn.config.codex_home)?;
         let env = attempt
             .env_for(spec, None)
             .map_err(|err| ToolError::Codex(err.into()))?;

codex-rs/windows-sandbox-rs/src/helper_materialization.rs

@@ -88,6 +88,34 @@ pub(crate) fn resolve_helper_for_launch(
     }
 }
 
+pub fn resolve_current_exe_for_launch(
+    codex_home: &Path,
+    fallback_executable: &str,
+) -> PathBuf {
+    let source = match std::env::current_exe() {
+        Ok(path) => path,
+        Err(_) => return PathBuf::from(fallback_executable),
+    };
+    let Some(file_name) = source.file_name() else {
+        return source;
+    };
+    let destination = helper_bin_dir(codex_home).join(file_name);
+    match copy_from_source_if_needed(&source, &destination) {
+        Ok(_) => destination,
+        Err(err) => {
+            let sandbox_log_dir = crate::sandbox_dir(codex_home);
+            log_note(
+                &format!(
+                    "helper copy failed for current executable: {err:#}; falling back to legacy path {}",
+                    source.display()
+                ),
+                Some(&sandbox_log_dir),
+            );
+            source
+        }
+    }
+}
+
 pub(crate) fn copy_helper_if_needed(
     kind: HelperExecutable,
     codex_home: &Path,
@@ -349,3 +377,4 @@ mod tests {
         );
     }
 }
+

codex-rs/windows-sandbox-rs/src/lib.rs

@@ -60,6 +60,8 @@ pub use dpapi::unprotect as dpapi_unprotect;
 #[cfg(target_os = "windows")]
 pub use elevated_impl::run_windows_sandbox_capture as run_windows_sandbox_capture_elevated;
 #[cfg(target_os = "windows")]
+pub use helper_materialization::resolve_current_exe_for_launch;
+#[cfg(target_os = "windows")]
 pub use hide_users::hide_current_user_profile_dir;
 #[cfg(target_os = "windows")]
 pub use hide_users::hide_newly_created_users;