On Tue, 15 Sep 2020 10:43:05 -0700
Jim Meyering <j...@meyering.net> wrote:
> One nit with the patch: this statement is duplicated:
>
> + position *p = firstpos - stk[-1].nfirstpos;
> + for (position *p = firstpos - stk[-1].nfirstpos;
I removed first declaration.
> And can you clarify your comment below?
>
> > The bug is introduced in commit cafb61533f5bfb989698e3924f97471498b2422b
> > which is a first patch I wrote, and I attach a patch to fix the bug.
>
> That commit refers to a Sept 13 change by Paul Eggert. Is that the
> patch you intended to reference?
Sorry, it points da0e8454a8e68035ef4b87dbb9097f85df6ece27.
Thanks,
Norihiro
From 9c5a68b9a3f84f2ec77fddfbbc07c617588d1e8a Mon Sep 17 00:00:00 2001
From: Norihiro Tanaka <nori...@kcn.ne.jp>
Date: Mon, 14 Sep 2020 22:21:05 +0900
Subject: [PATCH] dfa: fix failure in removal of epsilon closure
If there are a espilon in a branch and the closure is iterated, maybe fails
in removal of the node. The bug is introduced in
commit da0e8454a8e68035ef4b87dbb9097f85df6ece27.
* lib/dfa.c (dfaanalyze): Calculate backward transition for not only
concatenation but closure.
---
lib/dfa.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/lib/dfa.c b/lib/dfa.c
index 746c7b5..7851fab 100644
--- a/lib/dfa.c
+++ b/lib/dfa.c
@@ -2701,6 +2701,17 @@ dfaanalyze (struct dfa *d, bool searchflag)
case STAR:
case PLUS:
+ /* Every element in the lastpos of the argument is in the backward
+ set of every element in the firstpos. */
+ if (d->epsilon)
+ {
+ tmp.elems = lastpos - stk[-1].nlastpos;
+ tmp.nelem = stk[-1].nlastpos;
+ for (position *p = firstpos - stk[-1].nfirstpos;
+ p < firstpos; p++)
+ merge2 (&backward[p->index], &tmp, &merged);
+ }
+
/* Every element in the firstpos of the argument is in the follow
of every element in the lastpos. */
{
--
1.7.1
