Subject: bug#48264: [PATCH v3 01/15] Stop checking the constant default for enable_multibyte_characters

From: Spencer Baugh <[email-masked]>
Date: Thu, 6 May 2021 17:33:32 -0400

The default is a constant "t", and can't be changed. So we don't need
to check it. This makes enable_multibyte_characters like every other
permanently buffer-local variable defined with DEFVAR_PER_BUFFER.

* src/buffer.c (reset_buffer, init_buffer):
* src/print.c (print_string, temp_output_buffer_setup):
* src/process.c (Fmake_pipe_process, Fmake_serial_process)
(set_network_socket_coding_system):
Don't check buffer_defaults for enable_multibyte_characters
---
 src/buffer.c  |  5 +----
 src/print.c   |  6 ++----
 src/process.c | 15 ++++-----------
 3 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/src/buffer.c b/src/buffer.c
index 8e33162989..8b3e15bc81 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -988,8 +988,7 @@ reset_buffer (register struct buffer *b)
   bset_last_selected_window (b, Qnil);
   bset_display_count (b, make_fixnum (0));
   bset_display_time (b, Qnil);
-  bset_enable_multibyte_characters
-    (b, BVAR (&buffer_defaults, enable_multibyte_characters));
+  bset_enable_multibyte_characters (b, Qt);
   bset_cursor_type (b, BVAR (&buffer_defaults, cursor_type));
   bset_extra_line_spacing (b, BVAR (&buffer_defaults, extra_line_spacing));
 
@@ -5406,8 +5405,6 @@ init_buffer (void)
 
   AUTO_STRING (scratch, "*scratch*");
   Fset_buffer (Fget_buffer_create (scratch, Qnil));
-  if (NILP (BVAR (&buffer_defaults, enable_multibyte_characters)))
-    Fset_buffer_multibyte (Qnil);
 
   char const *pwd = emacs_wd;
 
diff --git a/src/print.c b/src/print.c
index d4301fd7b6..653f17aa1d 100644
--- a/src/print.c
+++ b/src/print.c
@@ -453,8 +453,7 @@ print_string (Lisp_Object string, Lisp_Object printcharfun)
 	chars = SCHARS (string);
       else if (! print_escape_nonascii
 	       && (EQ (printcharfun, Qt)
-		   ? ! NILP (BVAR (&buffer_defaults, enable_multibyte_characters))
-		   : ! NILP (BVAR (current_buffer, enable_multibyte_characters))))
+		   || ! NILP (BVAR (current_buffer, enable_multibyte_characters))))
 	{
 	  /* If unibyte string STRING contains 8-bit codes, we must
 	     convert STRING to a multibyte string containing the same
@@ -572,8 +571,7 @@ temp_output_buffer_setup (const char *bufname)
   bset_undo_list (current_buffer, Qt);
   eassert (current_buffer->overlays_before == NULL);
   eassert (current_buffer->overlays_after == NULL);
-  bset_enable_multibyte_characters
-    (current_buffer, BVAR (&buffer_defaults, enable_multibyte_characters));
+  bset_enable_multibyte_characters (current_buffer, Qt);
   specbind (Qinhibit_read_only, Qt);
   specbind (Qinhibit_modification_hooks, Qt);
   Ferase_buffer ();
diff --git a/src/process.c b/src/process.c
index 84e301a87a..44ba6c578e 100644
--- a/src/process.c
+++ b/src/process.c
@@ -2399,8 +2399,7 @@ usage:  (make-pipe-process &rest ARGS)  */)
       }
     else if (!NILP (Vcoding_system_for_read))
       val = Vcoding_system_for_read;
-    else if ((!NILP (buffer) && NILP (BVAR (XBUFFER (buffer), enable_multibyte_characters)))
-	     || (NILP (buffer) && NILP (BVAR (&buffer_defaults, enable_multibyte_characters))))
+    else if (!NILP (buffer) && NILP (BVAR (XBUFFER (buffer), enable_multibyte_characters)))
       /* We dare not decode end-of-line format by setting VAL to
 	 Qraw_text, because the existing Emacs Lisp libraries
 	 assume that they receive bare code including a sequence of
@@ -2425,8 +2424,6 @@ usage:  (make-pipe-process &rest ARGS)  */)
       }
     else if (!NILP (Vcoding_system_for_write))
       val = Vcoding_system_for_write;
-    else if (NILP (BVAR (current_buffer, enable_multibyte_characters)))
-      val = Qnil;
     else
       {
 	if (CONSP (coding_systems))
@@ -3124,8 +3121,7 @@ usage:  (make-serial-process &rest ARGS)  */)
     }
   else if (!NILP (Vcoding_system_for_read))
     val = Vcoding_system_for_read;
-  else if ((!NILP (buffer) && NILP (BVAR (XBUFFER (buffer), enable_multibyte_characters)))
-	   || (NILP (buffer) && NILP (BVAR (&buffer_defaults, enable_multibyte_characters))))
+  else if (!NILP (buffer) && NILP (BVAR (XBUFFER (buffer), enable_multibyte_characters)))
     val = Qnil;
   pset_decode_coding_system (p, val);
 
@@ -3138,8 +3134,7 @@ usage:  (make-serial-process &rest ARGS)  */)
     }
   else if (!NILP (Vcoding_system_for_write))
     val = Vcoding_system_for_write;
-  else if ((!NILP (buffer) && NILP (BVAR (XBUFFER (buffer), enable_multibyte_characters)))
-	   || (NILP (buffer) && NILP (BVAR (&buffer_defaults, enable_multibyte_characters))))
+  else if (!NILP (buffer) && NILP (BVAR (XBUFFER (buffer), enable_multibyte_characters)))
     val = Qnil;
   pset_encode_coding_system (p, val);
 
@@ -3181,9 +3176,7 @@ set_network_socket_coding_system (Lisp_Object proc, Lisp_Object host,
   else if (!NILP (Vcoding_system_for_read))
     val = Vcoding_system_for_read;
   else if ((!NILP (p->buffer)
-	    && NILP (BVAR (XBUFFER (p->buffer), enable_multibyte_characters)))
-	   || (NILP (p->buffer)
-	       && NILP (BVAR (&buffer_defaults, enable_multibyte_characters))))
+	    && NILP (BVAR (XBUFFER (p->buffer), enable_multibyte_characters))))
     /* We dare not decode end-of-line format by setting VAL to
        Qraw_text, because the existing Emacs Lisp libraries
        assume that they receive bare code including a sequence of
-- 
2.31.1