(encode_coding_utf_8): Initialize produced_chars to 0.

(decode_coding_utf_16): Fix converting high and low bytes to
code-point.
(encode_coding_utf_16): Substitute coding->default_char for
non-Unicode characters.
(decode_coding): Don't call record_insert here.
(setup_coding_system): Initialize `surrogate' of
coding->spec.utf_16 to 0.
(EMIT_ONE_BYTE): Fix for multibyte case.

1 files changed, 59 insertions, 52 deletions

diff --git a/src/coding.c b/src/coding.c
index 1c6a84d6f8d..60b2d3658c9 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -46,31 +46,23 @@ Boston, MA 02111-1307, USA.  */
 
 CODING SYSTEM
 
-  Coding system is an encoding mechanism of one or more character
-  sets.  Here's a list of coding system types supported by Emacs.
-  When we say "decode", it means converting a text encoded by some
-  coding system into Emacs' internal format (emacs-utf-8), and when we
-  say "encode", it means converting a text of emacs-utf-8 to some
-  other coding system.
-
-  Emacs represents a coding system by a Lisp symbol.  Each symbol is a
-  key to the hash table Vcharset_hash_table.  This hash table
-  associates the symbol to the corresponding detailed specifications.
-
-  Before using a coding system for decoding and encoding, we setup a
-  structure of type `struct coding_system'.  This structure keeps
-  various information about a specific code conversion (e.g.  the
-  location of source and destination data).
-
-  Coding systems are classified into the following types by how to
-  represent a character in a byte sequence.  Here's a brief descrition
-  about type.
-
-  o Emacs' internal format (emacs-utf-8)
-
-  The extended UTF-8 which allows eight-bit raw bytes mixed with
-  character codes.  Emacs holds characters in buffers and strings by
-  this format.
+  Coding system is an object for a encoding mechanism that contains
+  information about how to convert byte sequence to character
+  sequences and vice versa.  When we say "decode", it means converting
+  a byte sequence of a specific coding system into a character
+  sequence that is represented by Emacs' internal coding system
+  `emacs-utf-8', and when we say "encode", it means converting a
+  character sequence of emacs-utf-8 to a byte sequence of a specific
+  coding system.
+
+  In Emacs Lisp, a coding system is represented by a Lisp symbol.  In
+  C level, a coding system is represented by a vector of attributes
+  stored in the hash table Vcharset_hash_table.  The conversion from a
+  coding system symbol to attributes vector is done by looking up
+  Vcharset_hash_table by the symbol.
+
+  Coding systems are classified into the following types depending on
+  the mechanism of encoding.  Here's a brief descrition about type.
 
   o UTF-8
 
@@ -137,6 +129,13 @@ END-OF-LINE FORMAT
   independent, any coding system described above can take any format
   of end-of-line (except for no-conversion).
 
+STRUCT CODING_SYSTEM
+
+  Before using a coding system for code conversion (i.e. decoding and
+  encoding), we setup a structure of type `struct coding_system'.
+  This structure keeps various information about a specific code
+  conversion (e.g.  the location of source and destination data).
+
 */
 
 /* COMMON MACROS */
@@ -818,19 +817,27 @@ static int detected_mask[coding_category_raw_text] =
 
 /* Like EMIT_ONE_BYTE, but emit two bytes; C1 and C2.  */
 
-#define EMIT_TWO_BYTES(c1, c2)                  \
-  do {                                          \
-    produced_chars += 2;                        \
-    if (multibytep)                             \
-      {                                         \
-        CHAR_STRING_ADVANCE ((int) (c1), dst);  \
-        CHAR_STRING_ADVANCE ((int) (c2), dst);  \
-      }                                         \
-    else                                        \
-      {                                         \
-        *dst++ = (c1);                          \
-        *dst++ = (c2);                          \
-      }                                         \
+#define EMIT_TWO_BYTES(c1, c2)          \
+  do {                                  \
+    produced_chars += 2;                \
+    if (multibytep)                     \
+      {                                 \
+        int ch;                         \
+                                        \
+        ch = (c1);                      \
+        if (ch >= 0x80)                 \
+          ch = BYTE8_TO_CHAR (ch);      \
+        CHAR_STRING_ADVANCE (ch, dst);  \
+        ch = (c2);                      \
+        if (ch >= 0x80)                 \
+          ch = BYTE8_TO_CHAR (ch);      \
+        CHAR_STRING_ADVANCE (ch, dst);  \
+      }                                 \
+    else                                \
+      {                                 \
+        *dst++ = (c1);                  \
+        *dst++ = (c2);                  \
+      }                                 \
   } while (0)
 
 
@@ -889,10 +896,14 @@ coding_set_source (coding)
         coding->source = GAP_END_ADDR + coding->src_pos_byte;
       else
         {
-          if (coding->src_pos < GPT
-              && coding->src_pos + coding->src_chars >= GPT)
-            move_gap_both (coding->src_pos, coding->src_pos_byte);
-          coding->source = BYTE_POS_ADDR (coding->src_pos_byte);
+          struct buffer *buf = XBUFFER (coding->src_object);
+          EMACS_INT beg_byte = BUF_BEG_BYTE (buf);
+          EMACS_INT gpt_byte = BUF_GPT_BYTE (buf);
+          unsigned char *beg_addr = BUF_BEG_ADDR (buf);
+
+          coding->source = beg_addr + coding->src_pos_byte - 1;
+          if (coding->src_pos_byte >= gpt_byte)
+            coding->source += BUF_GAP_SIZE (buf);
         }
     }
   else if (STRINGP (coding->src_object))
@@ -1182,7 +1193,7 @@ encode_coding_utf_8 (coding)
   int *charbuf_end = charbuf + coding->charbuf_used;
   unsigned char *dst = coding->destination + coding->produced;
   unsigned char *dst_end = coding->destination + coding->dst_bytes;
-  int produced_chars;
+  int produced_chars = 0;
   int c;
 
   if (multibytep)
@@ -1290,7 +1301,7 @@ decode_coding_utf_16 (coding)
       src_base = src;
       ONE_MORE_BYTE (c1);
       ONE_MORE_BYTE (c2);
-      c = (c1 << 16) | c2;
+      c = (c1 << 8) | c2;
       if (bom == utf_16_with_bom)
         {
           if (endian == utf_16_big_endian
@@ -1333,7 +1344,7 @@ decode_coding_utf_16 (coding)
       ONE_MORE_BYTE (c1);
       ONE_MORE_BYTE (c2);
       c = (endian == utf_16_big_endian
-           ? ((c1 << 16) | c2) : ((c2 << 16) | c1));
+           ? ((c1 << 8) | c2) : ((c2 << 8) | c1));
       if (surrogate)
         {
           if (! UTF_16_LOW_SURROGATE_P (c))
@@ -1404,8 +1415,8 @@ encode_coding_utf_16 (coding)
     {
       ASSURE_DESTINATION (safe_room);
       c = *charbuf++;
-      if (c >= 0x110000)
-        c = 0xFFFF;
+      if (c >= MAX_UNICODE_CHAR)
+        c = coding->default_char;
 
       if (c < 0x10000)
         {
@@ -4504,6 +4515,7 @@ setup_coding_system (coding_system, coding)
       val = AREF (attrs, coding_attr_utf_16_endian);
       CODING_UTF_16_ENDIAN (coding) = (NILP (val) ? utf_16_big_endian
                                        : utf_16_little_endian);
+      CODING_UTF_16_SURROGATE (coding) = 0;
       coding->detector = detect_coding_utf_16;
       coding->decoder = decode_coding_utf_16;
       coding->encoder = encode_coding_utf_16;
@@ -5458,11 +5470,6 @@ decode_coding (coding)
       coding->consumed = coding->src_bytes;
     }
 
-  if (BUFFERP (coding->dst_object))
-    {
-      record_insert (coding->dst_pos, coding->produced_char);
-    }
-
   return coding->result;
 }