sgml-mode: Only set sgml-xml-mode if guessed to be an XML file

* lisp/textmodes/sgml-mode.el (sgml-mode): Don't override
sgml-xml-mode if the result of the guess is used as the buffer local
value.  (Bug#47877)

diff --git a/lisp/textmodes/sgml-mode.el b/lisp/textmodes/sgml-mode.el
index 67f731917e25dd61359aae76cdcd80b51713ae80..d5930e82df3ed0296547c64e9da5a3de25451a28 100644 (file)
--- a/lisp/textmodes/sgml-mode.el
+++ b/lisp/textmodes/sgml-mode.el
@@ -623,7 +623,8 @@ Do \\[describe-key] on the following bindings to discover what they do.
   (setq-local syntax-propertize-function #'sgml-syntax-propertize)
   (setq-local syntax-ppss-table sgml-tag-syntax-table)
   (setq-local facemenu-add-face-function 'sgml-mode-facemenu-add-face-function)
-  (setq-local sgml-xml-mode (sgml-xml-guess))
+  (when (sgml-xml-guess)
+    (setq-local sgml-xml-mode t))
   (unless sgml-xml-mode
     (setq-local skeleton-transformation-function sgml-transformation-function))
   ;; This will allow existing comments within declarations to be