(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;
     }