* lib/dfa.c (compare): Avoid integer overflow when analyzing
very large regular expressions.
---
ChangeLog | 4 ++++
lib/dfa.c | 9 ++-------
2 files changed, 6 insertions(+), 7 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index bc912c771..80b4abc5b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
2019-12-11 Paul Eggert <egg...@cs.ucla.edu>
+ dfa: fix index overflow
+ * lib/dfa.c (compare): Avoid integer overflow when analyzing
+ very large regular expressions.
+
dfa: update commentary for previous change
* NEWS: Mention the change.
* lib/dfa.c, lib/dfa.h (dfaparse, dfamust, dfacomp): Update comments.
diff --git a/lib/dfa.c b/lib/dfa.c
index 2347a91c1..ca123c68c 100644
--- a/lib/dfa.c
+++ b/lib/dfa.c
@@ -2423,13 +2423,8 @@ merge_nfa_state (struct dfa *d, size_t tindex, char
*flags,
static int
compare (const void *a, const void *b)
{
- int aindex;
- int bindex;
-
- aindex = (int) ((position *) a)->index;
- bindex = (int) ((position *) b)->index;
-
- return aindex - bindex;
+ position const *p = a, *q = b;
+ return p->index < q->index ? -1 : p->index > q->index;
}
static void
--
2.23.0
