From: Tanaka Akira <akr@...>
Date: 2008-02-25T17:53:49+09:00
Subject: Re: possible bug in regexp lexing

In article <87d4qpw02t.fsf@fsij.org>,
  Tanaka Akira <akr@fsij.org> writes:

> Isn't it the current behavior?

(c != '\\' || c != term) is same as
(c != '\\' || term != '\\').

So the condition is always true except term is '\\' as:
%r\abc\.

However tokadd_escape is not called if term is '\\' because
tokadd_string tests c == term for termination before calling
tokadd_escape.

So, (c != '\\' || c != term) is always true.

> An refactoring is good to do, though.

Index: parse.y
===================================================================
--- parse.y	(revision 15595)
+++ parse.y	(working copy)
@@ -2890,8 +2890,7 @@ read_escape()
 }
 
 static int
-tokadd_escape(term)
-    int term;
+tokadd_escape()
 {
     int c;
 
@@ -2956,7 +2955,7 @@ tokadd_escape(term)
 	tokadd('\\'); tokadd('c');
       escaped:
 	if ((c = nextc()) == '\\') {
-	    return tokadd_escape(term);
+	    return tokadd_escape();
 	}
 	else if (c == -1) goto eof;
 	tokadd(c);
@@ -2968,8 +2967,7 @@ tokadd_escape(term)
 	return -1;
 
       default:
-	if (c != '\\' || c != term)
-	    tokadd('\\');
+        tokadd('\\');
 	tokadd(c);
     }
     return 0;
@@ -3089,7 +3087,7 @@ tokadd_string(func, term, paren, nest)
 	      default:
 		if (func & STR_FUNC_REGEXP) {
 		    pushback(c);
-		    if (tokadd_escape(term) < 0)
+		    if (tokadd_escape() < 0)
 			return -1;
 		    continue;
 		}
-- 
Tanaka Akira