Improve display of raw bytes in the echo-area

* src/print.c (print_object): When printing a unibyte string,
convert non-ASCII bytes to their character code, before sending
them to 'printchar'.  (Bug#43632)

1 files changed, 27 insertions, 23 deletions

diff --git a/src/print.c b/src/print.c
index 0ecc98f37bf..dca095f2812 100644
--- a/src/print.c
+++ b/src/print.c
@@ -1929,7 +1929,7 @@ print_object (Lisp_Object obj, Lisp_Object printcharfun, bool escapeflag)
           ptrdiff_t i, i_byte;
           ptrdiff_t size_byte;
           /* True means we must ensure that the next character we output
-             cannot be taken as part of a hex character escape.  */
+             cannot be taken as part of a hex character escape.  */
           bool need_nonhex = false;
           bool multibyte = STRING_MULTIBYTE (obj);
 
@@ -1976,25 +1976,29 @@ print_object (Lisp_Object obj, Lisp_Object printcharfun, bool escapeflag)
                   /* If we just had a hex escape, and this character
                      could be taken as part of it,
                      output `\ ' to prevent that.  */
-                  if (c_isxdigit (c))
-                    {
-                      if (need_nonhex)
-                        print_c_string ("\\ ", printcharfun);
-                      printchar (c, printcharfun);
-                    }
-                  else if (c == '\n' && print_escape_newlines
-                           ? (c = 'n', true)
-                           : c == '\f' && print_escape_newlines
-                           ? (c = 'f', true)
-                           : c == '\"' || c == '\\')
-                    {
-                      printchar ('\\', printcharfun);
-                      printchar (c, printcharfun);
-                    }
-                  else if (print_escape_control_characters && c_iscntrl (c))
+                  if (c_isxdigit (c))
+                    {
+                      if (need_nonhex)
+                        print_c_string ("\\ ", printcharfun);
+                      printchar (c, printcharfun);
+                    }
+                  else if (c == '\n' && print_escape_newlines
+                           ? (c = 'n', true)
+                           : c == '\f' && print_escape_newlines
+                           ? (c = 'f', true)
+                           : c == '\"' || c == '\\')
+                    {
+                      printchar ('\\', printcharfun);
+                      printchar (c, printcharfun);
+                    }
+                  else if (print_escape_control_characters && c_iscntrl (c))
                     octalout (c, SDATA (obj), i_byte, size_byte, printcharfun);
-                  else
-                    printchar (c, printcharfun);
+                  else if (!multibyte
+                           && SINGLE_BYTE_CHAR_P (c)
+                           && !ASCII_CHAR_P (c))
+                    printchar (BYTE8_TO_CHAR (c), printcharfun);
+                  else
+                    printchar (c, printcharfun);
                   need_nonhex = false;
                 }
             }
@@ -2024,7 +2028,7 @@ print_object (Lisp_Object obj, Lisp_Object printcharfun, bool escapeflag)
                           && len == size_byte);
 
         if (! NILP (Vprint_gensym)
-            && !SYMBOL_INTERNED_IN_INITIAL_OBARRAY_P (obj))
+            && !SYMBOL_INTERNED_IN_INITIAL_OBARRAY_P (obj))
           print_c_string ("#:", printcharfun);
         else if (size_byte == 0)
           {
@@ -2047,7 +2051,7 @@ print_object (Lisp_Object obj, Lisp_Object printcharfun, bool escapeflag)
                     || c == ',' || c == '.' || c == '`'
                     || c == '[' || c == ']' || c == '?' || c <= 040
                     || c == NO_BREAK_SPACE
-                    || confusing)
+                    || confusing)
                   {
                     printchar ('\\', printcharfun);
                     confusing = false;
@@ -2112,7 +2116,7 @@ print_object (Lisp_Object obj, Lisp_Object printcharfun, bool escapeflag)
 
                   if (!NILP (Vprint_circle))
                     {
-                      /* With the print-circle feature.  */
+                      /* With the print-circle feature.  */
                       Lisp_Object num = Fgethash (obj, Vprint_number_table,
                                                   Qnil);
                       if (FIXNUMP (num))
@@ -2164,7 +2168,7 @@ print_object (Lisp_Object obj, Lisp_Object printcharfun, bool escapeflag)
       {
         int len;
         /* We're in trouble if this happens!
-           Probably should just emacs_abort ().  */
+           Probably should just emacs_abort ().  */
         print_c_string ("#<EMACS BUG: INVALID DATATYPE ", printcharfun);
         if (VECTORLIKEP (obj))
           len = sprintf (buf, "(PVEC 0x%08zx)", (size_t) ASIZE (obj));