Make mailcap consistent about regexp-quoting minors

* lisp/net/mailcap.el (mailcap-mime-data): Quote regexp.
(mailcap-mime-extensions): Ditto.
(mailcap--regexp-quote-type): New function.
(mailcap-parse-mimetype-file): Use it to get consistent quoting of
(regexp) strings (bug#52038).  Before you'd get both
application/vnd\.ms-excel and application/vnd.ms-excel (etc),
making prompting confusing.

1 files changed, 8 insertions, 3 deletions

diff --git a/lisp/net/mailcap.el b/lisp/net/mailcap.el
index a5f589459b7..b678df30bd4 100644
--- a/lisp/net/mailcap.el
+++ b/lisp/net/mailcap.el
@@ -125,7 +125,7 @@ is consulted."
      ("vnd\\.ms-excel"
       (viewer . "gnumeric %s")
       (test   . (getenv "DISPLAY"))
-      (type . "application/vnd.ms-excel"))
+      (type . "application/vnd\\.ms-excel"))
      ("octet-stream"
       (viewer . mailcap-save-binary-file)
       (non-viewer . t)
@@ -979,7 +979,7 @@ If NO-DECODE is non-nil, don't decode STRING."
     (".vox"   . "audio/basic")
     (".vrml"  . "x-world/x-vrml")
     (".wav"   . "audio/x-wav")
-    (".xls"   . "application/vnd.ms-excel")
+    (".xls"   . "application/vnd\\.ms-excel")
     (".wrl"   . "x-world/x-vrml")
     (".xbm"   . "image/xbm")
     (".xpm"   . "image/xpm")
@@ -1051,7 +1051,8 @@ If FORCE, re-parse even if already parsed."
         (setq save-pos (point))
         (skip-chars-forward "^ \t\n")
         (downcase-region save-pos (point))
-        (setq type (buffer-substring save-pos (point)))
+        (setq type (mailcap--regexp-quote-type
+                    (buffer-substring save-pos (point))))
         (while (not (eolp))
           (skip-chars-forward " \t")
           (setq save-pos (point))
@@ -1064,6 +1065,10 @@ If FORCE, re-parse even if already parsed."
         (setq mailcap-mime-extensions (append extns mailcap-mime-extensions)
               extns nil)))))
 
+(defun mailcap--regexp-quote-type (type)
+  (pcase-let ((`(,major ,minor) (split-string type "/")))
+    (concat major "/" (regexp-quote minor))))
+
 (defun mailcap-extension-to-mime (extn)
   "Return the MIME content type of the file extensions EXTN."
   (mailcap-parse-mimetypes)