Make c-emacs-features use the proper binding of parse-sexp-lookup-properties

This is relevant for bug #58558, although it does not fix it.  Due to a wrong
ordering of with-current-buffer and a let form, the function overwrote the
global value of parse-sexp-lookup-properties and two other variables.

* lisp/progmodes/cc-defs.el (c-emacs-features): Change the nesting of
with-current-buffer and let so that the let bindings get used.

1 files changed, 72 insertions, 79 deletions

diff --git a/lisp/progmodes/cc-defs.el b/lisp/progmodes/cc-defs.el
index aa6f33e9cab..1d98b215525 100644
--- a/lisp/progmodes/cc-defs.el
+++ b/lisp/progmodes/cc-defs.el
@@ -2153,86 +2153,79 @@ non-nil, a caret is prepended to invert the set."
     ;; Record whether the `category' text property works.
     (if c-use-category (setq list (cons 'category-properties list)))
 
-    (let ((buf (generate-new-buffer " test"))
-          parse-sexp-lookup-properties
-          parse-sexp-ignore-comments
-          lookup-syntax-properties)     ; XEmacs
+    (let ((buf (generate-new-buffer " test")))
       (with-current-buffer buf
-        (set-syntax-table (make-syntax-table))
-
-        ;; For some reason we have to set some of these after the
-        ;; buffer has been made current.  (Specifically,
-        ;; `parse-sexp-ignore-comments' in Emacs 21.)
-        (setq parse-sexp-lookup-properties t
-              parse-sexp-ignore-comments t
-              lookup-syntax-properties t)
-
-        ;; Find out if the `syntax-table' text property works.
-        (modify-syntax-entry ?< ".")
-        (modify-syntax-entry ?> ".")
-        (insert "<()>")
-        (c-mark-<-as-paren (point-min))
-        (c-mark->-as-paren (+ 3 (point-min)))
-        (goto-char (point-min))
-        (c-forward-sexp)
-        (if (= (point) (+ 4 (point-min)))
-            (setq list (cons 'syntax-properties list))
-          (error (concat
-                  "CC Mode is incompatible with this version of Emacs - "
-                  "support for the `syntax-table' text property "
-                  "is required.")))
-
-        ;; Find out if "\\s!" (generic comment delimiters) work.
-        (c-safe
-          (modify-syntax-entry ?x "!")
-          (if (string-match "\\s!" "x")
-              (setq list (cons 'gen-comment-delim list))))
-
-        ;; Find out if "\\s|" (generic string delimiters) work.
-        (c-safe
-          (modify-syntax-entry ?x "|")
-          (if (string-match "\\s|" "x")
-              (setq list (cons 'gen-string-delim list))))
-
-        ;; See if POSIX char classes work.
-        (when (and (string-match "[[:alpha:]]" "a")
-                   ;; All versions of Emacs 21 so far haven't fixed
-                   ;; char classes in `skip-chars-forward' and
-                   ;; `skip-chars-backward'.
-                   (progn
-                     (delete-region (point-min) (point-max))
-                     (insert "foo123")
-                     (skip-chars-backward "[:alnum:]")
-                     (bobp))
-                   (= (skip-chars-forward "[:alpha:]") 3))
-          (setq list (cons 'posix-char-classes list)))
-
-        ;; See if `open-paren-in-column-0-is-defun-start' exists and
-        ;; isn't buggy (Emacs >= 21.4).
-        (when (boundp 'open-paren-in-column-0-is-defun-start)
-          (let ((open-paren-in-column-0-is-defun-start nil)
-                (parse-sexp-ignore-comments t))
-            (delete-region (point-min) (point-max))
-            (set-syntax-table (make-syntax-table))
-            (modify-syntax-entry ?\' "\"")
-            (cond
-             ;; XEmacs.  Afaik this is currently an Emacs-only
-             ;; feature, but it's good to be prepared.
-             ((memq '8-bit list)
-              (modify-syntax-entry ?/ ". 1456")
-              (modify-syntax-entry ?* ". 23"))
-             ;; Emacs
-             ((memq '1-bit list)
-              (modify-syntax-entry ?/ ". 124b")
-              (modify-syntax-entry ?* ". 23")))
-            (modify-syntax-entry ?\n "> b")
-            (insert "/* '\n   () */")
-            (backward-sexp)
-            (if (bobp)
-                (setq list (cons 'col-0-paren list)))))
-
-        (set-buffer-modified-p nil))
-      (kill-buffer buf))
+        (let ((parse-sexp-lookup-properties t)
+              (parse-sexp-ignore-comments t)
+              (lookup-syntax-properties t))
+          (set-syntax-table (make-syntax-table))
+
+          ;; Find out if the `syntax-table' text property works.
+          (modify-syntax-entry ?< ".")
+          (modify-syntax-entry ?> ".")
+          (insert "<()>")
+          (c-mark-<-as-paren (point-min))
+          (c-mark->-as-paren (+ 3 (point-min)))
+          (goto-char (point-min))
+          (c-forward-sexp)
+          (if (= (point) (+ 4 (point-min)))
+              (setq list (cons 'syntax-properties list))
+            (error (concat
+                    "CC Mode is incompatible with this version of Emacs - "
+                    "support for the `syntax-table' text property "
+                    "is required.")))
+
+          ;; Find out if "\\s!" (generic comment delimiters) work.
+          (c-safe
+            (modify-syntax-entry ?x "!")
+            (if (string-match "\\s!" "x")
+                (setq list (cons 'gen-comment-delim list))))
+
+          ;; Find out if "\\s|" (generic string delimiters) work.
+          (c-safe
+            (modify-syntax-entry ?x "|")
+            (if (string-match "\\s|" "x")
+                (setq list (cons 'gen-string-delim list))))
+
+          ;; See if POSIX char classes work.
+          (when (and (string-match "[[:alpha:]]" "a")
+                     ;; All versions of Emacs 21 so far haven't fixed
+                     ;; char classes in `skip-chars-forward' and
+                     ;; `skip-chars-backward'.
+                     (progn
+                       (delete-region (point-min) (point-max))
+                       (insert "foo123")
+                       (skip-chars-backward "[:alnum:]")
+                       (bobp))
+                     (= (skip-chars-forward "[:alpha:]") 3))
+            (setq list (cons 'posix-char-classes list)))
+
+          ;; See if `open-paren-in-column-0-is-defun-start' exists and
+          ;; isn't buggy (Emacs >= 21.4).
+          (when (boundp 'open-paren-in-column-0-is-defun-start)
+            (let ((open-paren-in-column-0-is-defun-start nil)
+                  (parse-sexp-ignore-comments t))
+              (delete-region (point-min) (point-max))
+              (set-syntax-table (make-syntax-table))
+              (modify-syntax-entry ?\' "\"")
+              (cond
+               ;; XEmacs.  Afaik this is currently an Emacs-only
+               ;; feature, but it's good to be prepared.
+               ((memq '8-bit list)
+                (modify-syntax-entry ?/ ". 1456")
+                (modify-syntax-entry ?* ". 23"))
+               ;; Emacs
+               ((memq '1-bit list)
+                (modify-syntax-entry ?/ ". 124b")
+                (modify-syntax-entry ?* ". 23")))
+              (modify-syntax-entry ?\n "> b")
+              (insert "/* '\n   () */")
+              (backward-sexp)
+              (if (bobp)
+                  (setq list (cons 'col-0-paren list)))))
+
+          (set-buffer-modified-p nil))
+        (kill-buffer buf)))
 
     ;; Check how many elements `parse-partial-sexp' returns.
     (let ((ppss-size (or (c-safe (length