@@ -1,6 +1,6 @@

;;; texmathp-test.el --- tests for texmathp -*- lexical-binding: t; -*-

-;; Copyright (C) 2020-2021 Free Software Foundation, Inc.

+;; Copyright (C) 2020-2026 Free Software Foundation, Inc.

;; This file is part of AUCTeX.

@@ -68,4 +68,28 @@ c")

(LaTeX-mode)

(texmathp)))))

+;; bug#81327

+(ert-deftest texmathp-escaped-toggle-onoff ()

+ "Test if the math toggle or onoff-regexp is actually unescaped."

+ (should (with-temp-buffer

+ ;; LaTeX: \begin{tabular}{c}$a$\\$b$\end{tabular}

+ (insert "\\begin{tabular}{c}$a$\\\\$b$\\end{tabular}")

+ (LaTeX-mode)

+ (search-backward "b$")

+ (texmathp)))

+

+ (should (with-temp-buffer

+ ;; LaTeX: a\\\(b\)c

+ (insert "a\\\\\\(b\\)c")

+ (LaTeX-mode)

+ (search-backward "b")

+ (texmathp)))

+

+ (should-not (with-temp-buffer

+ ;; LaTeX: a\\(b\\)c

+ (insert "a\\\\(b\\\\)c")

+ (LaTeX-mode)

+ (search-backward "b")

+ (texmathp))))

+

;;; texmathp-test.el ends here

diff --git a/texmathp.el b/texmathp.el
index 7dd443a0150..a95fe948d9f 100644
--- a/texmathp.el
+++ b/texmathp.el

@@ -172,6 +172,18 @@

("dsuspend" env-off))

"The default entries for `texmathp-tex-commands', which see.")

+(defun texmathp--escaped-p (&optional pos)

+ "Return t if the character at position POS is escaped.

+If POS is omitted, examine the character at point.

+A character is escaped if it is preceded by an odd number of

+escape characters, namely \"\\\" in (La)TeX.

+

+This is a copy of `TeX-escaped-p' provided by tex.el in order to keep

+this library usable stand-alone."

+ (save-excursion

+ (when pos (goto-char pos))

+ (not (zerop (mod (skip-chars-backward (regexp-quote "\\")) 2)))))

+

(defun texmathp-compile ()

"Compile the value of `texmathp-tex-commands' into the internal lists.

Call this when you have changed the value of that variable without using

@@ -192,12 +204,8 @@ customize (customize calls it when setting the variable)."

((memq type '(arg-on arg-off)) (push (car entry) texmathp-macros))

((memq type '(sw-on sw-off)) (push (car entry) switches))

((memq type '(sw-toggle)) (push (car entry) togglers))))

- (setq texmathp-onoff-regexp

- (concat "\\(?:[^\\]\\|\\`\\)"

- (regexp-opt switches t))

- texmathp-toggle-regexp

- (concat "\\([^\\$]\\|\\`\\)"

- (regexp-opt togglers t)))))

+ (setq texmathp-onoff-regexp (regexp-opt switches t)

+ texmathp-toggle-regexp (regexp-opt togglers t))))

(defcustom texmathp-tex-commands nil

"List of environments and macros influencing (La)TeX math mode.

@@ -312,9 +320,12 @@ See the variable `texmathp-tex-commands' about which commands are checked."

(save-excursion

(goto-char (cdr match))

(while (re-search-forward texmathp-toggle-regexp pos t)

- (if (setq math-on (not math-on))

- (setq sw-match (cons (match-string-no-properties 2) (match-beginning 2)))

- (setq sw-match nil)))

+ ;; Check the toggle is unescaped (bug#81327):

+ (unless (texmathp--escaped-p (match-beginning 1))

+ (if (setq math-on (not math-on))

+ (setq sw-match (cons (match-string-no-properties 1)

+ (match-beginning 1)))

+ (setq sw-match nil))))

(and math-on sw-match (setq match sw-match))))

;; Store info, show as message when interactive, and return

@@ -447,9 +458,11 @@ Limit searches to BOUND. The return value is like (\"\\macro\" . (point))."

(defun texmathp-match-switch (bound)

"Search backward for any of the math switches.

Limit searched to BOUND."

- ;; The return value is like ("\\(" . (point)).

+ ;; The return value is like ("\\(" . (point)) only if "\\(" isn't

+ ;; escaped (bug#81327):

(save-excursion

- (if (re-search-backward texmathp-onoff-regexp bound t)

+ (if (and (re-search-backward texmathp-onoff-regexp bound t)

+ (not (texmathp--escaped-p)))

(cons (buffer-substring-no-properties (match-beginning 1) (match-end 1))

(match-beginning 1))

nil)))