1 files changed, 85 insertions, 74 deletions

diff --git a/lisp/international/utf-16.el b/lisp/international/utf-16.el
index 7786795f4a5..6ccac419f57 100644
--- a/lisp/international/utf-16.el
+++ b/lisp/international/utf-16.el
@@ -68,48 +68,49 @@
 ;; Needed in macro expansion, so can't be let-bound.  Zapped after use.
 (eval-and-compile
 (defconst utf-16-decode-ucs
-  ;; We have the unicode in r1.  Output is character codes in r0, r1,
-  ;; and r2 if appropriate.
-  `((lookup-integer utf-8-subst-table r0 r3)
-    (if r7 (r1 = r3))                   ; got a translation
-    (if (r1 < 128)
-       (r0 = ,(charset-id 'ascii))
-     (if (r1 < 160)
-         (r0 = ,(charset-id 'eight-bit-control))
-       (if (r1 < 256)
-           ((r0 = ,(charset-id 'latin-iso8859-1))
-            (r1 -= 128))
-         (if (r1 < #x2500)
-             ((r0 = ,(charset-id 'mule-unicode-0100-24ff))
-              (r1 -= #x100)
-              (r2 = (((r1 / 96) + 32) << 7))
-              (r1 %= 96)
-              (r1 += (r2 + 32)))
-           (if (r1 < #x3400)
-               ((r0 = ,(charset-id 'mule-unicode-2500-33ff))
-                (r1 -= #x2500)
-                (r2 = (((r1 / 96) + 32) << 7))
-                (r1 %= 96)
-                (r1 += (r2 + 32)))
-             (if (r1 < #xd800)          ; 2 untranslated bytes
-;;               ;; Assume this is rare, so don't worry about the
-;;               ;; overhead of the call.
-;;               (call mule-utf-16-untrans)
-                 ((r0 = ,(charset-id 'mule-unicode-e000-ffff))
-                  (r1 = 15037))         ; U+fffd
-               (if (r1 < #xe000)        ; surrogate
-;;                      ((call mule-utf-16-untrans)
-;;                       (write-multibyte-character r0 r1)
-;;                       (read r3 r4)
-;;                       (call mule-utf-16-untrans))
-                   ((read r3 r4)
-                    (r0 = ,(charset-id 'mule-unicode-e000-ffff))
-                    (r1 = 15037))
-                 ((r0 = ,(charset-id 'mule-unicode-e000-ffff))
-                  (r1 -= #xe000)
-                  (r2 = (((r1 / 96) + 32) << 7))
-                  (r1 %= 96)
-                  (r1 += (r2 + 32)))))))))))))
+  ;; We have the unicode in r1.  Output is charset ID in r0, code point
+  ;; in r1.
+  `((lookup-integer utf-subst-table-for-decode r1 r3)
+    (if r7                              ; got a translation
+        ((r0 = r1) (r1 = r3))
+      (if (r1 < 128)
+          (r0 = ,(charset-id 'ascii))
+        (if (r1 < 160)
+            (r0 = ,(charset-id 'eight-bit-control))
+          (if (r1 < 256)
+              ((r0 = ,(charset-id 'latin-iso8859-1))
+               (r1 -= 128))
+            (if (r1 < #x2500)
+                ((r0 = ,(charset-id 'mule-unicode-0100-24ff))
+                 (r1 -= #x100)
+                 (r2 = (((r1 / 96) + 32) << 7))
+                 (r1 %= 96)
+                 (r1 += (r2 + 32)))
+              (if (r1 < #x3400)
+                  ((r0 = ,(charset-id 'mule-unicode-2500-33ff))
+                   (r1 -= #x2500)
+                   (r2 = (((r1 / 96) + 32) << 7))
+                   (r1 %= 96)
+                   (r1 += (r2 + 32)))
+                (if (r1 < #xd800)       ; 2 untranslated bytes
+                    ;;           ;; Assume this is rare, so don't worry about the
+                    ;;           ;; overhead of the call.
+                    ;;           (call mule-utf-16-untrans)
+                    ((r0 = ,(charset-id 'mule-unicode-e000-ffff))
+                     (r1 = 15037))      ; U+fffd
+                  (if (r1 < #xe000)     ; surrogate
+                      ;;                        ((call mule-utf-16-untrans)
+                      ;;                         (write-multibyte-character r0 r1)
+                      ;;                         (read r3 r4)
+                      ;;                         (call mule-utf-16-untrans))
+                      ((read r3 r4)
+                       (r0 = ,(charset-id 'mule-unicode-e000-ffff))
+                       (r1 = 15037))
+                    ((r0 = ,(charset-id 'mule-unicode-e000-ffff))
+                     (r1 -= #xe000)
+                     (r2 = (((r1 / 96) + 32) << 7))
+                     (r1 %= 96)
+                     (r1 += (r2 + 32))))))))))))))
 
 (define-ccl-program ccl-decode-mule-utf-16-le
   `(2                                   ; 2 bytes -> 1 to 4 bytes
@@ -118,14 +119,14 @@
       (read r3 r4)
       (r1 = (r4 <8 r3))
       ,utf-16-decode-ucs
-      (translate-character utf-8-translation-table-for-decode r0 r1)
+      (translate-character utf-translation-table-for-decode r0 r1)
       (write-multibyte-character r0 r1)
       (repeat))))
   "Decode little endian UTF-16 (ignoring signature bytes).
 Basic decoding is done into the charsets ascii, latin-iso8859-1 and
-mule-unicode-*.  Un-representable Unicode characters are
-decoded as U+fffd.  The result is run through translation table
-`utf-8-translation-table-for-decode' if that is defined.")
+mule-unicode-*.  Un-representable Unicode characters are decoded as
+U+fffd.  The result is run through the translation-table named
+`utf-translation-table-for-decode'.")
 
 (define-ccl-program ccl-decode-mule-utf-16-be
   `(2                                   ; 2 bytes -> 1 to 4 bytes
@@ -134,14 +135,14 @@ decoded as U+fffd.  The result is run through translation table
       (read r3 r4)
       (r1 = (r3 <8 r4))
       ,utf-16-decode-ucs
-      (translate-character utf-8-translation-table-for-decode r0 r1)
+      (translate-character utf-translation-table-for-decode r0 r1)
       (write-multibyte-character r0 r1)
       (repeat))))
   "Decode big endian UTF-16 (ignoring signature bytes).
 Basic decoding is done into the charsets ascii, latin-iso8859-1 and
 mule-unicode-*.  Un-representable Unicode characters are
-decoded as U+fffd.  The result is run through translation table
-`utf-8-non-latin-8859-table'.")
+decoded as U+fffd.  The result is run through the translation-table of
+name `utf-translation-table-for-decode'.")
 
 (makunbound 'utf-16-decode-ucs)         ; done with it
 
@@ -176,15 +177,18 @@ decoded as U+fffd.  The result is run through translation table
      (write #xfe)
      (loop
       (read-multibyte-character r0 r1)
-      (translate-character ucs-mule-to-mule-unicode r0 r1)
-      ,utf-16-decode-to-ucs
+      (lookup-character utf-subst-table-for-encode r0 r1)
+      (if (r7 == 0)
+          ((translate-character utf-translation-table-for-encode r0 r1)
+           ,utf-16-decode-to-ucs))
       (write (r0 & 255))
       (write (r0 >> 8))
       (repeat))))
   "Encode to little endian UTF-16 with signature.
 Characters from the charsets ascii, eight-bit-control,
 eight-bit-graphic, latin-iso8859-1 and mule-unicode-* are encoded
-after translation through the table `ucs-mule-to-mule-unicode'.
+after translation through the translation-table of name
+`utf-translation-table-for-encode'.
 Others are encoded as U+FFFD.")
 
 (define-ccl-program ccl-encode-mule-utf-16-be
@@ -193,15 +197,18 @@ Others are encoded as U+FFFD.")
      (write #xff)
      (loop
       (read-multibyte-character r0 r1)
-      (translate-character ucs-mule-to-mule-unicode r0 r1)
-      ,utf-16-decode-to-ucs
+      (lookup-character utf-subst-table-for-encode r0 r1)
+      (if (r7 == 0)
+          ((translate-character utf-translation-table-for-encode r0 r1)
+           ,utf-16-decode-to-ucs))
       (write (r0 >> 8))
       (write (r0 & 255))
       (repeat))))
   "Encode to big endian UTF-16 with signature.
 Characters from the charsets ascii, eight-bit-control,
 eight-bit-graphic, latin-iso8859-1 and mule-unicode-* are encoded
-after translation through the table `ucs-mule-to-mule-unicode'.
+after translation through the translation-table named
+`utf-translation-table-for-encode'.
 Others are encoded as U+FFFD.")
 
 (makunbound 'utf-16-decode-to-ucs)
@@ -210,20 +217,19 @@ Others are encoded as U+FFFD.")
 
 Assumes and ignores the leading two-byte signature.
 
-The supported Emacs character sets are the following, plus others
-which may be included in the translation table
-`ucs-mule-to-mule-unicode':
- ascii
- eight-bit-control
- latin-iso8859-1
- mule-unicode-0100-24ff
- mule-unicode-2500-33ff
- mule-unicode-e000-ffff
-
-Note that Unicode characters out of the ranges U+0000-U+33FF and
-U+E200-U+FFFF are decoded as U+FFFD, effectively corrupting the data
-if they are re-encoded.  Emacs characters without Unicode conversions
-are encoded as U+FFFD."))
+It supports Unicode characters of these ranges:
+    U+0000..U+33FF, U+E000..U+FFFF.
+They correspond to these Emacs character sets:
+    ascii, latin-iso8859-1, mule-unicode-0100-24ff,
+    mule-unicode-2500-33ff, mule-unicode-e000-ffff
+
+On decoding (e.g. reading a file), Unicode characters not in the above
+ranges are decoded as U+FFFD, effectively corrupting the data
+if they are re-encoded.  
+
+On encoding (e.g. writing a file), Emacs characters not belonging to
+any of the character sets listed above are encoded into the byte
+sequence representing U+FFFD (REPLACEMENT CHARACTER)."))
   (make-coding-system
    'mule-utf-16-le 4
    ?u         ; Mule-UCS uses ?U, but code-pages uses that for koi8-u.
@@ -242,7 +248,11 @@ are encoded as U+FFFD."))
      (mime-charset . utf-16le)
      (coding-category . coding-category-utf-16-le)
      (valid-codes (0 . 255))
-     (pre-write-conversion . utf-16-le-pre-write-conversion)))
+     (pre-write-conversion . utf-16-le-pre-write-conversion)
+     (dependency unify-8859-on-encoding-mode
+                 unify-8859-on-decoding-mode
+                 utf-fragment-on-decoding
+                 utf-translate-cjk)))
 
   (make-coding-system
    'mule-utf-16-be 4 ?u
@@ -261,10 +271,11 @@ are encoded as U+FFFD."))
      (mime-charset . utf-16be)
      (coding-category . coding-category-utf-16-be)
      (valid-codes (0 . 255))
-     (pre-write-conversion . utf-16-be-pre-write-conversion)))
-
-  (register-char-codings 'mule-utf-16-le ucs-mule-to-mule-unicode)
-  (register-char-codings 'mule-utf-16-be ucs-mule-to-mule-unicode))
+     (pre-write-conversion . utf-16-be-pre-write-conversion)
+     (dependency unify-8859-on-encoding-mode
+                 unify-8859-on-decoding-mode
+                 utf-fragment-on-decoding
+                 utf-translate-cjk))))
 
 (define-coding-system-alias 'utf-16-le 'mule-utf-16-le)
 (define-coding-system-alias 'utf-16-be 'mule-utf-16-be)