(e_write): Short cut for the case of no encoding.

1 files changed, 31 insertions, 8 deletions

diff --git a/src/fileio.c b/src/fileio.c
index 17be7bf4d9c..d20e3eecf89 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -5362,18 +5362,41 @@ e_write (desc, string, start, end, coding)
   do
     {
       if (STRINGP (string))
-        encode_coding_object (coding, string,
-                              start, string_char_to_byte (string, start),
-                              end, string_char_to_byte (string, end), Qt);
+        {
+          coding->src_multibyte = SCHARS (string) < SBYTES (string);
+          if (CODING_REQUIRE_ENCODING (coding))
+            encode_coding_object (coding, string,
+                                  start, string_char_to_byte (string, start),
+                                  end, string_char_to_byte (string, end), Qt);
+          else
+            coding->dst_object = string, coding->produced = SBYTES (string);
+        }
       else
-        encode_coding_object (coding, Fcurrent_buffer (),
-                              start, CHAR_TO_BYTE (start),
-                              end, CHAR_TO_BYTE (end), Qt);
+        {
+          int start_byte = CHAR_TO_BYTE (start);
+          int end_byte = CHAR_TO_BYTE (end);
+
+          coding->src_multibyte = (end - start) < (end_byte - start_byte);
+          if (CODING_REQUIRE_ENCODING (coding))
+            encode_coding_object (coding, Fcurrent_buffer (),
+                                  start, CHAR_TO_BYTE (start),
+                                  end, CHAR_TO_BYTE (end), Qt);
+          else
+            {
+              coding->dst_object = Qnil;
+              coding->produced = end - start;
+              coding->dst_pos_byte = start_byte;
+            }
+        }
 
       if (coding->produced > 0)
         {
-          coding->produced -= emacs_write (desc, SDATA (coding->dst_object),
-                                           coding->produced);
+          coding->produced -=
+            emacs_write (desc,
+                         STRINGP (coding->dst_object)
+                         ? SDATA (coding->dst_object)
+                         : BYTE_POS_ADDR (coding->dst_pos_byte),
+                         coding->produced);
 
           if (coding->produced)
             {