(print_escape_nonascii): New variable.

(print) <Lisp_String>: Use it to force printing single-byte
non-ASCII characters as octal escapes.
(syms_of_print): Define print-escape-nonascii.

diff --git a/src/print.c b/src/print.c
index 879b48933c906f386562d2a08b5e94e1fd26d719..e9faec9118838dd3679ecadbe44275108548e395 100644 (file)
--- a/src/print.c
+++ b/src/print.c
@@ -130,6 +130,11 @@ int print_escape_newlines;
 
 Lisp_Object Qprint_escape_newlines;
 
+/* Nonzero means to print single-byte non-ascii characters in strings as
+   octal escapes.  */
+
+int print_escape_nonascii;
+
 /* Nonzero means print (quote foo) forms as 'foo, etc.  */
 
 int print_quoted;
@@ -1248,9 +1253,10 @@ print (obj, printcharfun, escapeflag)
                }
              else if (SINGLE_BYTE_CHAR_P (c)
                       && ! ASCII_BYTE_P (c)
-                      && ! NILP (current_buffer->enable_multibyte_characters))
+                      && (! NILP (current_buffer->enable_multibyte_characters)
+                          || print_escape_nonascii))
                {
-                 /* When multibyte is enabled,
+                 /* When multibyte is enabled or when explicitly requested,
                     print single-byte non-ASCII string chars
                     using octal escapes.  */
                  unsigned char outbuf[5];
@@ -1807,6 +1813,12 @@ A value of nil means no limit.");
 Also print formfeeds as backslash-f.");
   print_escape_newlines = 0;
 
+  DEFVAR_BOOL ("print-escape-nonascii", &print_escape_nonascii,
+    "Non-nil means print non-ASCII characters in strings as backslash-NNN.\n\
+NNN is the octal representation of the character's value.\n\
+Only single-byte characters are affected.");
+  print_escape_nonascii = 0;
+
   DEFVAR_BOOL ("print-quoted", &print_quoted,
     "Non-nil means print quoted forms with reader syntax.\n\
 I.e., (quote foo) prints as 'foo, (function foo) as #'foo, and, backquoted\n\