1 files changed, 105 insertions, 20 deletions

diff --git a/src/coding.c b/src/coding.c
index e6f544c8f87..901f81a9247 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -972,6 +972,66 @@ record_conversion_result (struct coding_system *coding,
   } while (0)
 
 
+/* Store multibyte form of the character C in P, and advance P to the
+   end of the multibyte form.  This is like CHAR_STRING_ADVANCE but it
+   never calls MAYBE_UNIFY_CHAR.  */
+
+#define CHAR_STRING_ADVANCE_NO_UNIFY(c, p)      \
+  do {                                          \
+    if ((c) <= MAX_1_BYTE_CHAR)                 \
+      *(p)++ = (c);                             \
+    else if ((c) <= MAX_2_BYTE_CHAR)            \
+      *(p)++ = (0xC0 | ((c) >> 6)),             \
+        *(p)++ = (0x80 | ((c) & 0x3F));         \
+    else if ((c) <= MAX_3_BYTE_CHAR)            \
+      *(p)++ = (0xE0 | ((c) >> 12)),            \
+        *(p)++ = (0x80 | (((c) >> 6) & 0x3F)),  \
+        *(p)++ = (0x80 | ((c) & 0x3F));         \
+    else if ((c) <= MAX_4_BYTE_CHAR)            \
+      *(p)++ = (0xF0 | (c >> 18)),              \
+        *(p)++ = (0x80 | ((c >> 12) & 0x3F)),   \
+        *(p)++ = (0x80 | ((c >> 6) & 0x3F)),    \
+        *(p)++ = (0x80 | (c & 0x3F));           \
+    else if ((c) <= MAX_5_BYTE_CHAR)            \
+      *(p)++ = 0xF8,                            \
+        *(p)++ = (0x80 | ((c >> 18) & 0x0F)),   \
+        *(p)++ = (0x80 | ((c >> 12) & 0x3F)),   \
+        *(p)++ = (0x80 | ((c >> 6) & 0x3F)),    \
+        *(p)++ = (0x80 | (c & 0x3F));           \
+    else                                        \
+      (p) += BYTE8_STRING ((c) - 0x3FFF80, p);  \
+  } while (0)
+
+
+/* Return the character code of character whose multibyte form is at
+   P, and advance P to the end of the multibyte form.  This is like
+   STRING_CHAR_ADVANCE, but it never calls MAYBE_UNIFY_CHAR.  */
+
+#define STRING_CHAR_ADVANCE_NO_UNIFY(p)                         \
+  (!((p)[0] & 0x80)                                             \
+   ? *(p)++                                                     \
+   : ! ((p)[0] & 0x20)                                          \
+   ? ((p) += 2,                                                 \
+      ((((p)[-2] & 0x1F) << 6)                                  \
+       | ((p)[-1] & 0x3F)                                       \
+       | ((unsigned char) ((p)[-2]) < 0xC2 ? 0x3FFF80 : 0)))    \
+   : ! ((p)[0] & 0x10)                                          \
+   ? ((p) += 3,                                                 \
+      ((((p)[-3] & 0x0F) << 12)                                 \
+       | (((p)[-2] & 0x3F) << 6)                                \
+       | ((p)[-1] & 0x3F)))                                     \
+   : ! ((p)[0] & 0x08)                                          \
+   ? ((p) += 4,                                                 \
+      ((((p)[-4] & 0xF) << 18)                                  \
+       | (((p)[-3] & 0x3F) << 12)                               \
+       | (((p)[-2] & 0x3F) << 6)                                \
+       | ((p)[-1] & 0x3F)))                                     \
+   : ((p) += 5,                                                 \
+      ((((p)[-4] & 0x3F) << 18)                                 \
+       | (((p)[-3] & 0x3F) << 12)                               \
+       | (((p)[-2] & 0x3F) << 6)                                \
+       | ((p)[-1] & 0x3F))))
+
 
 static void
 coding_set_source (coding)
@@ -1037,20 +1097,23 @@ coding_alloc_by_realloc (coding, bytes)
 }
 
 static void
-coding_alloc_by_making_gap (coding, offset, bytes)
+coding_alloc_by_making_gap (coding, gap_head_used, bytes)
      struct coding_system *coding;
-     EMACS_INT offset, bytes;
+     EMACS_INT gap_head_used, bytes;
 {
-  if (BUFFERP (coding->dst_object)
-      && EQ (coding->src_object, coding->dst_object))
+  if (EQ (coding->src_object, coding->dst_object))
     {
-      EMACS_INT add = offset + (coding->src_bytes - coding->consumed);
+      /* The gap may contain the produced data at the head and not-yet
+         consumed data at the tail.  To preserve those data, we at
+         first make the gap size to zero, then increase the gap
+         size.  */
+      EMACS_INT add = GAP_SIZE;
 
-      GPT += offset, GPT_BYTE += offset;
-      GAP_SIZE -= add; ZV += add; Z += add; ZV_BYTE += add; Z_BYTE += add;
+      GPT += gap_head_used, GPT_BYTE += gap_head_used;
+      GAP_SIZE = 0; ZV += add; Z += add; ZV_BYTE += add; Z_BYTE += add;
       make_gap (bytes);
       GAP_SIZE += add; ZV -= add; Z -= add; ZV_BYTE -= add; Z_BYTE -= add;
-      GPT -= offset, GPT_BYTE -= offset;
+      GPT -= gap_head_used, GPT_BYTE -= gap_head_used;
     }
   else
     {
@@ -1073,7 +1136,11 @@ alloc_destination (coding, nbytes, dst)
   EMACS_INT offset = dst - coding->destination;
 
   if (BUFFERP (coding->dst_object))
-    coding_alloc_by_making_gap (coding, offset, nbytes);
+    {
+      struct buffer *buf = XBUFFER (coding->dst_object);
+
+      coding_alloc_by_making_gap (coding, dst - BUF_GPT_ADDR (buf), nbytes);
+    }
   else
     coding_alloc_by_realloc (coding, nbytes);
   record_conversion_result (coding, CODING_RESULT_SUCCESS);
@@ -1365,7 +1432,7 @@ encode_coding_utf_8 (coding)
             }
           else
             {
-              CHAR_STRING_ADVANCE (c, pend);
+              CHAR_STRING_ADVANCE_NO_UNIFY (c, pend);
               for (p = str; p < pend; p++)
                 EMIT_ONE_BYTE (*p);
             }
@@ -1382,7 +1449,7 @@ encode_coding_utf_8 (coding)
           if (CHAR_BYTE8_P (c))
             *dst++ = CHAR_TO_BYTE8 (c);
           else
-            dst += CHAR_STRING (c, dst);
+            CHAR_STRING_ADVANCE_NO_UNIFY (c, dst);
           produced_chars++;
         }
     }
@@ -5971,9 +6038,11 @@ produce_chars (coding, translation_table, last_block)
       int *buf = coding->charbuf;
       int *buf_end = buf + coding->charbuf_used;
 
-      if (BUFFERP (coding->src_object)
-          && EQ (coding->src_object, coding->dst_object))
-        dst_end = ((unsigned char *) coding->source) + coding->consumed;
+      if (EQ (coding->src_object, coding->dst_object))
+        {
+          coding_set_source (coding);
+          dst_end = ((unsigned char *) coding->source) + coding->consumed;
+        }
 
       while (buf < buf_end)
         {
@@ -6000,7 +6069,13 @@ produce_chars (coding, translation_table, last_block)
                                            buf_end - buf
                                            + MAX_MULTIBYTE_LENGTH * to_nchars,
                                            dst);
-                  dst_end = coding->destination + coding->dst_bytes;
+                  if (EQ (coding->src_object, coding->dst_object))
+                    {
+                      coding_set_source (coding);
+                      dst_end = ((unsigned char *) coding->source) + coding->consumed;
+                    }
+                  else
+                    dst_end = coding->destination + coding->dst_bytes;
                 }
 
               for (i = 0; i < to_nchars; i++)
@@ -6009,7 +6084,7 @@ produce_chars (coding, translation_table, last_block)
                     c = XINT (AREF (trans, i));
                   if (coding->dst_multibyte
                       || ! CHAR_BYTE8_P (c))
-                    CHAR_STRING_ADVANCE (c, dst);
+                    CHAR_STRING_ADVANCE_NO_UNIFY (c, dst);
                   else
                     *dst++ = CHAR_TO_BYTE8 (c);
                 }
@@ -6030,6 +6105,8 @@ produce_chars (coding, translation_table, last_block)
       const unsigned char *src = coding->source;
       const unsigned char *src_end = src + coding->consumed;
 
+      if (EQ (coding->dst_object, coding->src_object))
+        dst_end = (unsigned char *) src;
       if (coding->src_multibyte != coding->dst_multibyte)
         {
           if (coding->src_multibyte)
@@ -6057,6 +6134,8 @@ produce_chars (coding, translation_table, last_block)
                           coding_set_source (coding);
                           src = coding->source + offset;
                           src_end = coding->source + coding->src_bytes;
+                          if (EQ (coding->src_object, coding->dst_object))
+                            dst_end = (unsigned char *) src;
                         }
                     }
                   *dst++ = c;
@@ -6078,13 +6157,19 @@ produce_chars (coding, translation_table, last_block)
                     if (dst >= dst_end - 1)
                       {
                         EMACS_INT offset = src - coding->source;
+                        EMACS_INT more_bytes;
 
-                        dst = alloc_destination (coding, src_end - src + 2,
-                                                 dst);
+                        if (EQ (coding->src_object, coding->dst_object))
+                          more_bytes = ((src_end - src) / 2) + 2;
+                        else
+                          more_bytes = src_end - src + 2;
+                        dst = alloc_destination (coding, more_bytes, dst);
                         dst_end = coding->destination + coding->dst_bytes;
                         coding_set_source (coding);
                         src = coding->source + offset;
                         src_end = coding->source + coding->src_bytes;
+                        if (EQ (coding->src_object, coding->dst_object))
+                          dst_end = (unsigned char *) src;
                       }
                   }
                 EMIT_ONE_BYTE (c);
@@ -6572,12 +6657,12 @@ consume_chars (coding, translation_table, max_lookup)
           if (coding->encoder == encode_coding_raw_text)
             c = *src++, pos++;
           else if ((bytes = MULTIBYTE_LENGTH (src, src_end)) > 0)
-            c = STRING_CHAR_ADVANCE (src), pos += bytes;
+            c = STRING_CHAR_ADVANCE_NO_UNIFY (src), pos += bytes;
           else
             c = BYTE8_TO_CHAR (*src), src++, pos++;
         }
       else
-        c = STRING_CHAR_ADVANCE (src), pos++;
+        c = STRING_CHAR_ADVANCE_NO_UNIFY (src), pos++;
       if ((c == '\r') && (coding->mode & CODING_MODE_SELECTIVE_DISPLAY))
         c = '\n';
       if (! EQ (eol_type, Qunix))