regex: read/print bug: escaped double quote.

Because the regex printer wrongly uses out_str_char (for the
sake of borrowing its semicolon-notation processing) when
a regex prints, all characters that require escaping in a
string literal get escaped, which includes the " character.
Unfortunately the \" sequence which results is rejected
by the regex parser.

* lib.c (out_str_char): Kludge: add extra argument to
distinguish regex use versus string use, and treat the double
quote accordingly.
(out_str_readable): Give 0 arg to new param of out_str_char.

* lib.h (out_str_char): Declaration updated.

* regex.c (print_class_char, print_rec): Pass 1 to new param
of out_str_char.

1 files changed, 2 insertions, 2 deletions

diff --git a/regex.c b/regex.c
index 47693e97..3fb6b42c 100644
--- a/regex.c
+++ b/regex.c
@@ -2272,7 +2272,7 @@ static void print_class_char(val ch, val first_p, val stream, int *semi_flag)
     put_char(ch, stream);
     return;
   }
-  out_str_char(c_chr(ch), stream, semi_flag);
+  out_str_char(c_chr(ch), stream, semi_flag, 1);
 }
 
 static void print_rec(val exp, val stream, int *semi_flag);
@@ -2311,7 +2311,7 @@ static void print_rec(val exp, val stream, int *semi_flag)
       put_char(exp, stream);
       break;
     default:
-      out_str_char(ch, stream, semi_flag);
+      out_str_char(ch, stream, semi_flag, 1);
     }
   } else if (stringp(exp)) {
     cnum i;