(set_auto_coding_unwind): New function.

(Finsert_file_contents): If the current buffer is empty, decide
the coding system after the file is inserted in the buffer.  If
not, insert the head and tail of a file in a temporary buffer and
call set-auto-coding-function.
(e_write): If there are carryover bytes in encoding because of
incomplete multibyte form, write them out as is.

1 files changed, 189 insertions, 149 deletions

diff --git a/src/fileio.c b/src/fileio.c
index 66ac9587342..742c7ad95fe 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -3246,6 +3246,26 @@ Lisp_Object Qfind_buffer_file_type;
 #define READ_BUF_SIZE (64 << 10)
 #endif
 
+/* This function is called when a function bound to
+   Vset_auto_coding_function causes some error.  At that time, a text
+   of a file has already been inserted in the current buffer, but,
+   markers has not yet been adjusted.  Thus we must adjust markers
+   here.  We are sure that the buffer was empty before the text of the
+   file was inserted.  */
+
+static Lisp_Object
+set_auto_coding_unwind (multibyte)
+     Lisp_Object multibyte;
+{
+  int inserted = Z_BYTE - BEG_BYTE;
+
+  if (!NILP (multibyte))
+    inserted = multibyte_chars_in_text (GPT_ADDR - inserted, inserted);
+  adjust_after_insert (PT, PT_BYTE, Z, Z_BYTE, inserted);
+
+  return Qnil;
+}
+
 DEFUN ("insert-file-contents", Finsert_file_contents, Sinsert_file_contents,
   1, 5, 0,
   "Insert contents of file FILENAME after point.\n\
@@ -3290,6 +3310,7 @@ actually used.")
   unsigned char buffer[1 << 14];
   int replace_handled = 0;
   int set_coding_system = 0;
+  int coding_system_decided = 0;
 
   if (current_buffer->base_buffer && ! NILP (visit))
     error ("Cannot do file visiting in an indirect buffer");
@@ -3392,161 +3413,107 @@ actually used.")
         }
     }
 
-  /* Decide the coding-system of the file.  */
-  {
-    Lisp_Object val;
-    val = Qnil;
-
-    if (!NILP (Vcoding_system_for_read))
-      val = Vcoding_system_for_read;
-    else if (! NILP (replace))
-      /* In REPLACE mode, we can use the same coding system
-         that was used to visit the file.  */
-      val = current_buffer->buffer_file_coding_system;
-    else if (! not_regular)
-      {
-        /* Don't try looking inside a file for a coding system specification
-           if it is not seekable.  */
-        if (! NILP (Vset_auto_coding_function))
-          {
-            /* Find a coding system specified in the heading two lines
-               or in the tailing several lines of the file.  We assume
-               that the 1K-byte and 3K-byte for heading and tailing
-               respectively are sufficient fot this purpose.  */
-            int nread;
-            int beginning_of_end, end_of_beginning;
-
-            if (st.st_size <= (1024 * 4))
-              {
-                nread = read (fd, read_buf, 1024 * 4);
-                end_of_beginning = nread;
-                beginning_of_end = 0;
-              }
-            else
-              {
-                nread = read (fd, read_buf, 1024);
-                end_of_beginning = nread;
-                beginning_of_end = nread;
-                if (nread >= 0)
-                  {
-                    if (lseek (fd, st.st_size - (1024 * 3), 0) < 0)
-                      report_file_error ("Setting file position",
-                                         Fcons (orig_filename, Qnil));
-                    nread += read (fd, read_buf + nread, 1024 * 3);
-                  }
-              }
+  if (BEG < Z)
+    {
+      /* Decide the coding system to use for reading the file now
+         because we can't use an optimized method for handling
+         `coding:' tag if the current buffer is not empty.  */
+      Lisp_Object val;
+      val = Qnil;
 
-            if (nread < 0)
-              error ("IO error reading %s: %s",
-                     XSTRING (orig_filename)->data, strerror (errno));
-            else if (nread > 0)
-              {
-                int i;
-                int possible_spec = 0;
-                unsigned char *p, *p1;
-                Lisp_Object tem;
-                unsigned char *copy = (unsigned char *) alloca (nread + 1);
-
-                /* Make a copy of the contents of read_buf in COPY, 
-                   and convert it to lower case so we can compare
-                   more efficiently.  */
-                bcopy (read_buf, copy, nread);
-                for (i = 0; i < nread; i++)
-                  copy[i] = DOWNCASE (copy[i]);
-                /* Ensure various comparisons fail at end of data.  */
-                copy[nread] = 0;
-
-                /* Now test quickly whether the file contains a -*- line.  */
-                p = copy;
-                while (*p != '\n' && p - copy < end_of_beginning)
-                  p++;
-                if (copy[0] == '#' && copy[1] == '!')
-                  while (*p != '\n' && p - copy < end_of_beginning)
-                    p++;
-                p1 = copy;
-                while (p - p1 >= 3)
-                  {
-                    if (p1[0] == '-' && p1[1] == '*' && p1[2] == '-')
-                      {
-                        while (p - p1 >= 7)
-                          {
-                            if (! bcmp ("coding:", p1, 7))
-                              {
-                                possible_spec = 1;
-                                goto win;
-                              }
-                            p1++;
-                          }
-                        break;
-                      }
-                    p1++;
-                  }
+      if (!NILP (Vcoding_system_for_read))
+        val = Vcoding_system_for_read;
+      else if (! NILP (replace))
+        /* In REPLACE mode, we can use the same coding system
+           that was used to visit the file.  */
+        val = current_buffer->buffer_file_coding_system;
+      else
+        {
+          /* Don't try looking inside a file for a coding system
+             specification if it is not seekable.  */
+          if (! not_regular && ! NILP (Vset_auto_coding_function))
+            {
+              /* Find a coding system specified in the heading two
+                 lines or in the tailing several lines of the file.
+                 We assume that the 1K-byte and 3K-byte for heading
+                 and tailing respectively are sufficient fot this
+                 purpose.  */
+              int how_many, nread;
+
+              if (st.st_size <= (1024 * 4))
+                nread = read (fd, read_buf, 1024 * 4);
+              else
+                {
+                  nread = read (fd, read_buf, 1024);
+                  if (nread >= 0)
+                    {
+                      if (lseek (fd, st.st_size - (1024 * 3), 0) < 0)
+                        report_file_error ("Setting file position",
+                                           Fcons (orig_filename, Qnil));
+                      nread += read (fd, read_buf + nread, 1024 * 3);
+                    }
+                }
 
-                /* Test quickly whether the file
-                   contains a local variables list.  */
-                p = &copy[nread - 1];
-                p1 = &copy[beginning_of_end];
-                while (p > p1)
-                  {
-                    if (p[0] == '\n' && p[1] == '\f')
-                      break;
-                    p--;
-                  }
-                p1 = &copy[nread];
-                while (p1 - p >= 16)
-                  {
-                    if (! bcmp ("local variables:", p, 16))
-                      {
-                        possible_spec = 1;
-                        break;
-                      }
-                    p++;
-                  }
-              win:
+              if (nread < 0)
+                error ("IO error reading %s: %s",
+                       XSTRING (orig_filename)->data, strerror (errno));
+              else if (nread > 0)
+                {
+                  int count = specpdl_ptr - specpdl;
+                  struct buffer *prev = current_buffer;
+
+                  record_unwind_protect (Fset_buffer, Fcurrent_buffer ());
+                  temp_output_buffer_setup (" *code-converting-work*");
+                  set_buffer_internal (XBUFFER (Vstandard_output));
+                  current_buffer->enable_multibyte_characters = Qnil;
+                  insert_1_both (read_buf, nread, nread, 0, 0, 0);
+                  TEMP_SET_PT_BOTH (BEG, BEG_BYTE);
+                  val = call1 (Vset_auto_coding_function, make_number (nread));
+                  set_buffer_internal (prev);
+                  /* Discard the unwind protect for recovering the
+                     current buffer.  */
+                  specpdl_ptr--;
+
+                  /* Rewind the file for the actual read done later.  */
+                  if (lseek (fd, 0, 0) < 0)
+                    report_file_error ("Setting file position",
+                                       Fcons (orig_filename, Qnil));
+                }
+            }
 
-                if (possible_spec)
-                  {
-                    /* Always make this a unibyte string
-                       because we have not yet decoded it.  */ 
-                    tem = make_unibyte_string (read_buf, nread);
-                    val = call1 (Vset_auto_coding_function, tem);
-                  }
+          if (NILP (val))
+            {
+              /* If we have not yet decided a coding system, check
+                 file-coding-system-alist.  */
+              Lisp_Object args[6], coding_systems;
+
+              args[0] = Qinsert_file_contents, args[1] = orig_filename;
+              args[2] = visit, args[3] = beg, args[4] = end, args[5] = replace;
+              coding_systems = Ffind_operation_coding_system (6, args);
+              if (CONSP (coding_systems))
+                val = XCONS (coding_systems)->car;
+            }
+        }
 
-                /* Rewind the file for the actual read done later.  */
-                if (lseek (fd, 0, 0) < 0)
-                  report_file_error ("Setting file position",
-                                     Fcons (orig_filename, Qnil));
-              }
-          }
-        if (NILP (val))
-          {
-            Lisp_Object args[6], coding_systems;
+      setup_coding_system (Fcheck_coding_system (val), &coding);
 
-            args[0] = Qinsert_file_contents, args[1] = orig_filename;
-            args[2] = visit, args[3] = beg, args[4] = end, args[5] = replace;
-            coding_systems = Ffind_operation_coding_system (6, args);
-            if (CONSP (coding_systems))
-              val = XCONS (coding_systems)->car;
-          }
-      }
+      if (NILP (Vcoding_system_for_read)
+          && NILP (current_buffer->enable_multibyte_characters))
+        {
+          /* We must suppress all text conversion except for end-of-line
+             conversion.  */
+          int eol_type;
 
-    if (NILP (Vcoding_system_for_read)
-        && NILP (current_buffer->enable_multibyte_characters))
-      {
-        /* We must suppress all text conversion except for end-of-line
-           conversion.  */
-        struct coding_system coding_temp;
+          eol_type = coding.eol_type;
+          setup_coding_system (Qraw_text, &coding);
+          coding.eol_type = eol_type;
+        }
 
-        setup_coding_system (Fcheck_coding_system (val), &coding_temp);
-        setup_coding_system (Qraw_text, &coding);
-        coding.eol_type = coding_temp.eol_type;
-      }
-    else
-      setup_coding_system (Fcheck_coding_system (val), &coding);
+      coding_system_decided = 1;
+    }
 
-    /* Ensure we always set Vlast_coding_system_used.  */
-    set_coding_system = 1;
-  }
+  /* Ensure we always set Vlast_coding_system_used.  */
+  set_coding_system = 1;
 
   /* If requested, replace the accessible part of the buffer
      with the file contents.  Avoid replacing text at the
@@ -3563,6 +3530,7 @@ actually used.")
      But if we discover the need for conversion, we give up on this method
      and let the following if-statement handle the replace job.  */
   if (!NILP (replace)
+      && BEGV < ZV
       && ! CODING_REQUIRE_DECODING (&coding)
       && (coding.eol_type == CODING_EOL_UNDECIDED
           || coding.eol_type == CODING_EOL_LF))
@@ -3741,7 +3709,7 @@ actually used.")
      is needed, in a simple way that needs a lot of memory.
      The preceding if-statement handles the case of no conversion
      in a more optimized way.  */
-  if (!NILP (replace) && ! replace_handled)
+  if (!NILP (replace) && ! replace_handled && BEGV < ZV)
     {
       int same_at_start = BEGV_BYTE;
       int same_at_end = ZV_BYTE;
@@ -3993,6 +3961,69 @@ actually used.")
 
   if (inserted > 0)
     {
+      if (! coding_system_decided)
+        {
+          /* The coding system is not yet decided.  Decide it by an
+             optimized method for handling `coding:' tag.  */
+          Lisp_Object val;
+          val = Qnil;
+
+          if (!NILP (Vcoding_system_for_read))
+            val = Vcoding_system_for_read;
+          else
+            {
+              if (! NILP (Vset_auto_coding_function))
+                {
+                  /* Since we are sure that the current buffer was
+                     empty before the insertion, we can toggle
+                     enable-multibyte-characters directly here without
+                     taking care of marker adjustment and byte
+                     combining problem.  */
+                  Lisp_Object prev_multibyte;
+                  int count = specpdl_ptr - specpdl;
+
+                  prev_multibyte = current_buffer->enable_multibyte_characters;
+                  current_buffer->enable_multibyte_characters = Qnil;
+                  record_unwind_protect (set_auto_coding_unwind,
+                                         prev_multibyte);
+                  val = call1 (Vset_auto_coding_function,
+                               make_number (inserted));
+                  /* Discard the unwind protect for recovering the
+                     error of Vset_auto_coding_function.  */
+                  specpdl_ptr--;
+                  current_buffer->enable_multibyte_characters = prev_multibyte;
+                  TEMP_SET_PT_BOTH (BEG, BEG_BYTE);
+                }
+
+              if (NILP (val))
+                {
+                  /* If the coding system is not yet decided, check
+                     file-coding-system-alist.  */
+                  Lisp_Object args[6], coding_systems;
+
+                  args[0] = Qinsert_file_contents, args[1] = orig_filename;
+                  args[2] = visit, args[3] = beg, args[4] = end, args[5] = Qnil;
+                  coding_systems = Ffind_operation_coding_system (6, args);
+                  if (CONSP (coding_systems))
+                    val = XCONS (coding_systems)->car;
+                }
+            }
+
+          setup_coding_system (Fcheck_coding_system (val), &coding);
+
+          if (NILP (Vcoding_system_for_read)
+              && NILP (current_buffer->enable_multibyte_characters))
+            {
+              /* We must suppress all text conversion except for
+                 end-of-line conversion.  */
+              int eol_type;
+
+              eol_type = coding.eol_type;
+              setup_coding_system (Qraw_text, &coding);
+              coding.eol_type = eol_type;
+            }
+        }
+
       if (CODING_MAY_REQUIRE_DECODING (&coding))
         {
           /* Here, we don't have to consider byte combining (see the
@@ -4763,13 +4794,22 @@ e_write (desc, addr, nbytes, coding)
      now it is handled within encode_coding.  */
   while (1)
     {
-      encode_coding (coding, addr, buf, nbytes, WRITE_BUF_SIZE);
+      int result;
+
+      result = encode_coding (coding, addr, buf, nbytes, WRITE_BUF_SIZE);
       nbytes -= coding->consumed, addr += coding->consumed;
       if (coding->produced > 0)
         {
           coding->produced -= write (desc, buf, coding->produced);
           if (coding->produced) return -1;
         }
+      if (result == CODING_FINISH_INSUFFICIENT_SRC)
+        {
+          /* The source text ends by an incomplete multibyte form.
+             There's no way other than write it out as is.  */
+          nbytes -= write (desc, addr, nbytes);
+          if (nbytes) return -1;
+        }
       if (nbytes <= 0)
         break;
     }