From: Noam Postavsky <npostavs@gmail.com>
Date: Wed, 15 May 2019 22:51:30 +0000 (-0400)
Subject: Fix merge of sgml-syntax-propertize-rules
X-Git-Tag: emacs-27.0.90~2878
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=e7e92dc5d24ac3bcde69732bab6a6c3c0d9de97b;p=emacs.git

Fix merge of sgml-syntax-propertize-rules

During the merge of emacs-26, the sgml-syntax-propertize-rules part of
2019-01-17 "* lisp/textmodes/sgml-mode.el: Try and fix bug#33887." got
lost in the conflict against 2019-05-09 "Recognize single quote
attribute values in nxml and sgml (Bug#35381)".
* lisp/textmodes/sgml-mode.el (sgml-syntax-propertize-rules): Reapply
the 2019-01-17 change to speed up sgml-syntax-propertize-rules, taking
into account the 2019-05-09 which means we have to handle single
quotes as well.
---

diff --git a/lisp/textmodes/sgml-mode.el b/lisp/textmodes/sgml-mode.el
index 6dc1b9e727e..11b30537e67 100644
--- a/lisp/textmodes/sgml-mode.el
+++ b/lisp/textmodes/sgml-mode.el
@@ -339,12 +339,21 @@ Any terminating `>' or `/' is not matched.")
      ("--[ \t\n]*\\(>\\)" (1 "> b"))
      ("\\(<\\)[?!]" (1 (prog1 "|>"
                          (sgml-syntax-propertize-inside end))))
-     ;; Quotes outside of tags should not introduce strings.
-     ;; Be careful to call `syntax-ppss' on a position before the one we're
-     ;; going to change, so as not to need to flush the data we just computed.
-     ("[\"']" (0 (if (prog1 (zerop (car (syntax-ppss (match-beginning 0))))
-                       (goto-char (match-end 0)))
-                     (string-to-syntax ".")))))))
+     ;; Quotes outside of tags should not introduce strings which end up
+     ;; hiding tags.  We used to test every quote and mark it as "."
+     ;; if it's outside of tags, but there are too many quotes and
+     ;; the resulting number of calls to syntax-ppss made it too slow
+     ;; (bug#33887), so we're now careful to leave alone any pair
+     ;; of quotes that doesn't hold a < or > char, which is the vast majority.
+     ("\\(?:\\(1:\"\\)[^\"<>]*[<>\"]\\|\\(1:'\\)[^'<>]*[<>']\\)"
+      (1 (unless (memq (char-before) '(?\' ?\"))
+           ;; Be careful to call `syntax-ppss' on a position before the one
+           ;; we're going to change, so as not to need to flush the data we
+           ;; just computed.
+           (if (prog1 (zerop (car (syntax-ppss (match-beginning 0))))
+                 (goto-char (1- (match-end 0))))
+               (string-to-syntax ".")))))
+     )))
 
 (defun sgml-syntax-propertize (start end)
   "Syntactic keywords for `sgml-mode'."