Fix byte-compiler warning for failed uses of lexical vars

* lisp/emacs-lisp/bytecomp.el (byte-compile-form): Fix byte-compiler
warning for failed uses of lexical vars.  (Bug#44980)
* test/lisp/emacs-lisp/bytecomp-tests.el
(bytecomp--define-warning-file-test): Don't prefix tests with
'warn'.
(bytecomp/error-lexical-var-with-add-hook\.el)
(bytecomp/error-lexical-var-with-remove-hook\.el)
(bytecomp/error-lexical-var-with-run-hook-with-args-until-failure\.el)
(bytecomp/error-lexical-var-with-run-hook-with-args-until-success\.el)
(bytecomp/error-lexical-var-with-run-hook-with-args\.el)
(bytecomp/error-lexical-var-with-symbol-value\.el): New tests.
* test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-symbol-value.el:
* test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-run-hook-with-args.el:
* test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-run-hook-with-args-until-success.el:
* test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-run-hook-with-args-until-failure.el:
* test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-remove-hook.el:
* test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-add-hook.el:
New files.

8 files changed, 45 insertions, 4 deletions

diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index a20f3634560..879f08a09f6 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -3203,7 +3203,7 @@ for symbols generated by the byte compiler itself."
                              run-hook-with-args-until-failure))
           (pcase (cdr form)
             (`(',var . ,_)
-             (when (assq var byte-compile-lexical-variables)
+             (when (memq var byte-compile-lexical-variables)
                (byte-compile-report-error
                 (format-message "%s cannot use lexical var `%s'" fn var))))))
         ;; Warn about using obsolete hooks.
diff --git a/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-add-hook.el b/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-add-hook.el
new file mode 100644
index 00000000000..5f390898e6a
--- /dev/null
+++ b/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-add-hook.el
@@ -0,0 +1,4 @@
+;;; -*- lexical-binding: t; -*-
+(let ((foo nil))
+  (add-hook 'foo #'next-line)
+  foo)
diff --git a/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-remove-hook.el b/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-remove-hook.el
new file mode 100644
index 00000000000..eaa625eba1c
--- /dev/null
+++ b/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-remove-hook.el
@@ -0,0 +1,4 @@
+;;; -*- lexical-binding: t; -*-
+(let ((foo nil))
+  (remove-hook 'foo #'next-line)
+  foo)
diff --git a/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-run-hook-with-args-until-failure.el b/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-run-hook-with-args-until-failure.el
new file mode 100644
index 00000000000..7a116ad464b
--- /dev/null
+++ b/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-run-hook-with-args-until-failure.el
@@ -0,0 +1,3 @@
+;;; -*- lexical-binding: t; -*-
+(let ((foo nil))
+  (run-hook-with-args-until-failure 'foo))
diff --git a/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-run-hook-with-args-until-success.el b/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-run-hook-with-args-until-success.el
new file mode 100644
index 00000000000..96d10a343df
--- /dev/null
+++ b/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-run-hook-with-args-until-success.el
@@ -0,0 +1,3 @@
+;;; -*- lexical-binding: t; -*-
+(let ((foo nil))
+  (run-hook-with-args-until-success 'foo #'next-line))
diff --git a/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-run-hook-with-args.el b/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-run-hook-with-args.el
new file mode 100644
index 00000000000..bb9101bd070
--- /dev/null
+++ b/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-run-hook-with-args.el
@@ -0,0 +1,3 @@
+;;; -*- lexical-binding: t; -*-
+(let ((foo nil))
+  (run-hook-with-args 'foo))
diff --git a/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-symbol-value.el b/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-symbol-value.el
new file mode 100644
index 00000000000..5f390898e6a
--- /dev/null
+++ b/test/lisp/emacs-lisp/bytecomp-resources/error-lexical-var-with-symbol-value.el
@@ -0,0 +1,4 @@
+;;; -*- lexical-binding: t; -*-
+(let ((foo nil))
+  (add-hook 'foo #'next-line)
+  foo)
diff --git a/test/lisp/emacs-lisp/bytecomp-tests.el b/test/lisp/emacs-lisp/bytecomp-tests.el
index bea9663d241..d9052da5436 100644
--- a/test/lisp/emacs-lisp/bytecomp-tests.el
+++ b/test/lisp/emacs-lisp/bytecomp-tests.el
@@ -548,7 +548,7 @@ Subtests signal errors if something goes wrong."
   (should (equal (funcall 'def) -1)))
 
 (defmacro bytecomp--define-warning-file-test (file re-warning &optional reverse)
-  `(ert-deftest ,(intern (format "bytecomp-warn/%s" file)) ()
+  `(ert-deftest ,(intern (format "bytecomp/%s" file)) ()
      :expected-result ,(if reverse :failed :passed)
      (with-current-buffer (get-buffer-create "*Compile-Log*")
        (let ((inhibit-read-only t)) (erase-buffer))
@@ -556,9 +556,29 @@ Subtests signal errors if something goes wrong."
        (ert-info ((buffer-string) :prefix "buffer: ")
          (should (re-search-forward ,re-warning))))))
 
-(bytecomp--define-warning-file-test "warn-free-setq.el" "free.*foo")
+(bytecomp--define-warning-file-test "error-lexical-var-with-add-hook.el"
+                            "add-hook.*lexical var")
 
-(bytecomp--define-warning-file-test "warn-free-variable-reference.el" "free.*bar")
+(bytecomp--define-warning-file-test "error-lexical-var-with-remove-hook.el"
+                            "remove-hook.*lexical var")
+
+(bytecomp--define-warning-file-test "error-lexical-var-with-run-hook-with-args-until-failure.el"
+                            "args-until-failure.*lexical var")
+
+(bytecomp--define-warning-file-test "error-lexical-var-with-run-hook-with-args-until-success.el"
+                            "args-until-success.*lexical var")
+
+(bytecomp--define-warning-file-test "error-lexical-var-with-run-hook-with-args.el"
+                            "args.*lexical var")
+
+(bytecomp--define-warning-file-test "error-lexical-var-with-symbol-value.el"
+                            "symbol-value.*lexical var")
+
+(bytecomp--define-warning-file-test "warn-free-setq.el"
+                            "free.*foo")
+
+(bytecomp--define-warning-file-test "warn-free-variable-reference.el"
+                            "free.*bar")
 
 (bytecomp--define-warning-file-test "warn-obsolete-defun.el"
                             "foo-obsolete.*obsolete function.*99.99")