Commit c4782ea5 authored by Eli Zaretskii's avatar Eli Zaretskii
Browse files

Improve and extend filepos-to-bufferpos

* lisp/international/mule-util.el (filepos-to-bufferpos--dos):
Don't barf if F returns nil for some argument.
(filepos-to-bufferpos): Expand to support UTF-16 and not assume
that every encoding of type 'charset' is single-byte.
parent 517ab623
......@@ -320,6 +320,12 @@ per-character basis, this may not be accurate."
(while
(progn
(setq pos (funcall f (- byte eol-offset)))
;; Protect against accidental values of BYTE outside of the
;; valid region.
(when (null pos)
(if (<= byte eol-offset)
(setq pos (point-min))
(setq pos (point-max))))
;; Adjust POS for DOS EOL format.
(setq lines (1- (line-number-at-pos pos)))
(and (not (= lines eol-offset)) (> omax omin)))
......@@ -345,7 +351,25 @@ QUALITY can be:
(unless coding-system (setq coding-system buffer-file-coding-system))
(let ((eol (coding-system-eol-type coding-system))
(type (coding-system-type coding-system))
(base (coding-system-base coding-system))
(pm (save-restriction (widen) (point-min))))
(and (eq type 'utf-8-emacs)
(setq type 'utf-8))
(and (eq type 'utf-8)
;; Any post-read/pre-write conversions mean it's not really UTF-8.
(not (null (coding-system-get coding-system :pos-read-conversion)))
(setq type 'not-utf-8))
(and (not (eq type 'utf-8))
(eq quality 'exact)
(setq type 'use-exact))
(and (memq type '(charset raw-text undecided))
;; The following are all of type 'charset', but they are
;; actually variable-width encodings.
(not (memq base '(chinese-gbk chinese-gb18030 euc-tw euc-jis-2004
korean-iso-8bit chinese-iso-8bit
japanese-iso-8bit chinese-big5-hkscs
japanese-cp932 korean-cp949)))
(setq type 'single-byte))
(pcase type
(`utf-8
(when (coding-system-get coding-system :bom)
......@@ -353,8 +377,16 @@ QUALITY can be:
(if (= eol 1)
(filepos-to-bufferpos--dos (+ pm byte) #'byte-to-position)
(byte-to-position (+ pm byte))))
;; FIXME: What if it's a 2-byte charset? Are there such beasts?
(`charset
(`utf-16
;; Account for BOM, which is always 2 bytes in UTF-16.
(setq byte (- byte 2))
;; In approximate mode, assume all characters are within the
;; BMP, i.e. take up 2 bytes.
(setq byte (/ byte 2))
(if (= eol 1)
(filepos-to-bufferpos--dos (+ pm byte) #'byte-to-position)
(byte-to-position (+ pm byte))))
(`single-byte
(if (= eol 1)
(filepos-to-bufferpos--dos (+ pm byte) #'identity)
(+ pm byte)))
......
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