Give a better error message when reading invalid "\unicode" escapes.

* src/lread.c (read_escape): Give a clearer error message on
Unicode escape sequences (bug#36988).

diff --git a/src/lread.c b/src/lread.c
index e444830c99ae7ad353acdb879a21f63e7a2b0133..6ae7a0d8ba0a5cdd9c3ec9c5974f9b0018feffbb 100644 (file)
--- a/src/lread.c
+++ b/src/lread.c
@@ -2585,7 +2585,8 @@ read_escape (Lisp_Object readcharfun, bool stringp)
               want.  */
            int digit = char_hexdigit (c);
            if (digit < 0)
-             error ("Non-hex digit used for Unicode escape");
+             error ("Non-hex character used for Unicode escape: %c (%d)",
+                    c, c);
            i = (i << 4) + digit;
          }
        if (i > 0x10FFFF)