From fcddd9c175cba2511558cba4e6e2e0005d821da5 Mon Sep 17 00:00:00 2001
From: Marius Gerbershagen <marius.gerbershagen@gmail.com>
Date: Tue, 3 Mar 2026 20:55:09 +0100
Subject: [PATCH] compiler.d: fix order of evaluation bug for nested eval-when
 forms

---
 src/c/compiler.d                    |  2 ++
 src/tests/normal-tests/compiler.lsp | 23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/src/c/compiler.d b/src/c/compiler.d
index 15a005815..23b4930b0 100644
--- a/src/c/compiler.d
+++ b/src/c/compiler.d
@@ -1649,10 +1649,12 @@ c_eval_when(cl_env_ptr env, cl_object args, int flags) {
       args = ECL_NIL;
   } else if (when_load_p(situation)) {
     if (when_compile_p(situation)) {
+      int result = compile_toplevel_body(env, args, flags);
       int current_mode = c_env->mode;
       c_env->mode = FLAG_EXECUTE;
       execute_each_form(env, args);
       c_env->mode = current_mode;
+      return result;
     }
   } else if (when_compile_p(situation)) {
     int current_mode = c_env->mode;
diff --git a/src/tests/normal-tests/compiler.lsp b/src/tests/normal-tests/compiler.lsp
index 044f5d305..5a3d9dce8 100644
--- a/src/tests/normal-tests/compiler.lsp
+++ b/src/tests/normal-tests/compiler.lsp
@@ -2678,3 +2678,26 @@
     (is (typep (first +c.0113.3+) 'base-string))
     (is (string= (first +c.0113.4+) "bb"))
     (is (and (typep (first +c.0113.4+) 'string) (not (typep (first +c.0113.4+) 'base-string))))))
+
+;;; Date 2026-03-05
+;;; Description
+;;;
+;;;     Wrong order of evaluation for nested eval-when forms in the
+;;;     bytecompiler.
+;;;
+(test cmp.0114.nested-eval-when
+  (eval '(defparameter *nested-eval-when-0114* ""))
+  (let* ((part-1 "So the last will be first, ")
+         (part-2 "and the first will be last.")
+         (ofile
+          (with-compiler ("nested-eval-when-0114.lsp")
+            `(eval-when (:load-toplevel :compile-toplevel :execute)
+               (eval-when (:compile-toplevel)
+                 (setf *nested-eval-when-0114*
+                       (concatenate 'string *nested-eval-when-0114* ,part-1)))
+               (setf *nested-eval-when-0114*
+                     (concatenate 'string *nested-eval-when-0114* ,part-2))))))
+    (delete-file "nested-eval-when-0114.lsp")
+    (delete-file ofile)
+    (is (equal (concatenate 'string part-1 part-2)
+               *nested-eval-when-0114*))))