From 6c9a1deb41f0a9d3dd7e8615a0015a74a851b426 Mon Sep 17 00:00:00 2001 From: Eli Zaretskii Date: Sat, 18 May 2019 10:15:19 +0300 Subject: [PATCH] Fix visiting and saving UTF-16 encoded XML files * lisp/international/mule.el (sgml-xml-auto-coding-function): When the 'enncoding' tag specifies a UTF-16 encoding, enforce saving the buffer with BOM, per the XML spec. (xml-find-file-coding-system): Recognize UTF-16 encodings with BOM. (Bug#35766) (Bug#8282) * lisp/international/mule-cmds.el (select-safe-coding-system): Don't consider UTF-16 encodings with and without BOM as "different", so as not to annoy users with redundant questions about mismatch between the XML/SGML header and the selected explicit encoding. --- lisp/international/mule-cmds.el | 8 +++++++- lisp/international/mule.el | 22 +++++++++++++++++++--- 2 files changed, 26 insertions(+), 4 deletions(-) diff --git a/lisp/international/mule-cmds.el b/lisp/international/mule-cmds.el index dfa9e4e6c8c..27296ecfb2c 100644 --- a/lisp/international/mule-cmds.el +++ b/lisp/international/mule-cmds.el @@ -1029,7 +1029,13 @@ It is highly recommended to fix it before writing to a file." ;; This check perhaps isn't ideal, but is probably ;; the best thing to do. (not (auto-coding-alist-lookup (or file buffer-file-name ""))) - (not (coding-system-equal coding-system auto-cs))) + (not (coding-system-equal coding-system auto-cs)) + ;; coding-system-equal barfs on 'charset'. + (or (equal (coding-system-type auto-cs) 'charset) + (equal (coding-system-type coding-system) 'charset) + (not (coding-system-equal (coding-system-type auto-cs) + (coding-system-type + coding-system))))) (unless (yes-or-no-p (format "Selected encoding %s disagrees with \ %s specified by file contents. Really save (else edit coding cookies \ diff --git a/lisp/international/mule.el b/lisp/international/mule.el index b5414de0dba..21f3118a98e 100644 --- a/lisp/international/mule.el +++ b/lisp/international/mule.el @@ -2498,7 +2498,18 @@ This function is intended to be added to `auto-coding-functions'." (when end (if (re-search-forward "encoding=[\"']\\(.+?\\)[\"']" end t) (let* ((match (match-string 1)) - (sym (intern (downcase match)))) + (sym-name (downcase match)) + (sym-name + ;; https://www.w3.org/TR/xml/#charencoding says: + ;; "Entities encoded in UTF-16 MUST [...] begin + ;; with the Byte Order Mark." The trick below is + ;; based on the fact that utf-16be/le don't + ;; specify BOM, while utf-16-be/le do. + (cond + ((equal sym-name "utf-16le") "utf-16-le") + ((equal sym-name "utf-16be") "utf-16-be") + (t sym-name))) + (sym (intern sym-name))) (if (coding-system-p sym) ;; If the encoding tag is UTF-8 and the buffer's ;; encoding is one of the variants of UTF-8, use the @@ -2587,9 +2598,14 @@ added by processing software." (let ((detected (with-coding-priority '(utf-8) (coding-system-base - (detect-coding-region (point-min) (point-max) t))))) - ;; Pure ASCII always comes back as undecided. + (detect-coding-region (point-min) (point-max) t)))) + (bom (list (char-after 1) (char-after 2)))) (cond + ((equal bom '(#xFE #xFF)) + 'utf-16be-with-signature) + ((equal bom '(#xFF #xFE)) + 'utf-16le-with-signature) + ;; Pure ASCII always comes back as undecided. ((memq detected '(utf-8 undecided)) 'utf-8) ((eq detected 'utf-16le-with-signature) 'utf-16le-with-signature) -- 2.39.2