[elpa] externals/mathjax 8c35f39ade: Apply some code review suggestions

[ELPA Syncer]

branch: externals/mathjax
commit 8c35f39adefca645cace9cc2ad623257f1cabe4c
Author: Augusto Stoffel <arstoffel@gmail.com>
Commit: Augusto Stoffel <arstoffel@gmail.com>

    Apply some code review suggestions
---
 .gitignore       |  5 +++++
 math2svg/main.js |  2 +-
 mathjax.el       | 23 ++++++++++++++++-------
 3 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/.gitignore b/.gitignore
index 4c60eb5193..fad6b5fd46 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,8 @@
 .dir-locals.el
 autoloads.el
 *.elc
+math2svg.js*
+
+# ELPA-generated files.
+mathjax-pkg.el
+mathjax-autoloads.el
diff --git a/math2svg/main.js b/math2svg/main.js
index b8114cfae6..0fe3c74969 100644
--- a/math2svg/main.js
+++ b/math2svg/main.js
@@ -17,7 +17,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-// Cf. https://github.com/mathjax/MathJax-demos-node/blob/master/simple
+// Cf. https://github.com/mathjax/MathJax-demos-node/blob/master/preload
 
 const config = JSON.parse(process.argv[2] || "{}")
 MathJax = {
diff --git a/mathjax.el b/mathjax.el
index 74371c64c7..478d227d89 100644
--- a/mathjax.el
+++ b/mathjax.el
@@ -4,6 +4,7 @@
 
 ;; Author: Augusto Stoffel <arstoffel@gmail.com>
 ;; URL: https://github.com/astoff/mathjax.el
+;; Package-Requires: ((emacs "27.1"))
 ;; Version: 0
 ;; Keywords: tex, text, tools
 
@@ -37,9 +38,12 @@
 (defvar mathjax--ttl 60
   "Time to let the MathJax process live without producing output.")
 
-(defvar mathjax--installation-directory (if load-file-name
-                                            (file-name-directory 
load-file-name)
-                                          default-directory)
+(defvar mathjax--installation-directory
+  (if-let ((file (if (fboundp 'macroexp-file-name) ;Emacs≥28.
+                     (macroexp-file-name)
+                   load-file-name)))
+      (file-name-directory file)
+    default-directory)
   "Directory where the `mathjax' package is installed.")
 
 (defun mathjax-available-p ()
@@ -136,7 +140,12 @@ FORMAT and OPTIONS are passed directly to 
`mathjax-render', which see."
          (callback
           (lambda (data)
             (when (and (buffer-live-p buffer)
-                       (< start end)) ;funky erase-buffer detection
+                       ;; Normally we allow buffer modifications
+                       ;; between the time `mathjax-display' is called
+                       ;; and the callback is called, but not if the
+                       ;; region was deleted entirely.  Hence the test
+                       ;; below.
+                       (< start end))
               (with-current-buffer buffer
                 (dolist (ov (overlays-at start))
                   (when (eq (overlay-get ov 'category) 'mathjax)
@@ -146,9 +155,9 @@ FORMAT and OPTIONS are passed directly to `mathjax-render', 
which see."
                   (overlay-put ov 'category 'mathjax)
                   (overlay-put ov 'evaporate t)
                   (when-let ((svg (alist-get 'svg data)))
-                    (let* ((h (and (string-match "height=\"\\([-.0-9]*\\)" svg)
+                    (let* ((h (and (string-match "height=\"\\([-.0-9]+\\)" svg)
                                    (string-to-number (match-string 1 svg))))
-                           (va (and (string-match "vertical-align: 
\\([-.0-9]*\\)" svg)
+                           (va (and (string-match "vertical-align: 
\\([-.0-9]+\\)" svg)
                                     (string-to-number (match-string 1 svg))))
                            (ascent (if (and h va) (round (* 100 (+ va h) (/ 
h))) 100))
                            (image (svg-image svg :ascent ascent)))
@@ -183,7 +192,7 @@ line.")
 (defun mathjax--math-searchfn (items)
   "Return a function to search for math regions.
 
-ITEMS should be a list like `mathjax-delimiers'.  The returned function
+ITEMS should be a list like `mathjax-delimiters'.  The returned function
 takes one argument, the search bound, and returns a list of the form
 
   (OUTER-START INNER-START INNER-END OUTER-END . OPTIONS)