Attachment "1810038.patch" to
ticket [1810038fff]
added by
dgp
2007-11-16 04:32:23.
Index: generic/regc_nfa.c
===================================================================
RCS file: /cvsroot/tcl/tcl/generic/regc_nfa.c,v
retrieving revision 1.9
diff -u -r1.9 regc_nfa.c
--- generic/regc_nfa.c 15 Nov 2007 17:07:11 -0000 1.9
+++ generic/regc_nfa.c 15 Nov 2007 21:31:14 -0000
@@ -859,6 +859,25 @@
}
/*
+ * DGP 2007-11-15: Cloning a state with a circular constraint on its list
+ * of outs can lead to trouble [Bug 1810038], so get rid of them first.
+ */
+
+ for (a = from->outs; a != NULL; a = nexta) {
+ nexta = a->outchain;
+ switch (a->type) {
+ case '^':
+ case '$':
+ case BEHIND:
+ case AHEAD:
+ if (from == a->to) {
+ freearc(nfa, a);
+ }
+ break;
+ }
+ }
+
+ /*
* First, clone from state if necessary to avoid other outarcs.
*/
@@ -997,6 +1016,28 @@
}
/*
+ * DGP 2007-11-15: Here we duplicate the same protections as appear
+ * in pull() above to avoid troubles with cloning a state with a
+ * circular constraint on its list of ins. It is not clear whether
+ * this is necessary, or is protecting against a "can't happen".
+ * Any test case that actually leads to a freearc() call here would
+ * be a welcome addition to the test suite.
+ */
+
+ for (a = to->ins; a != NULL; a = nexta) {
+ nexta = a->inchain;
+ switch (a->type) {
+ case '^':
+ case '$':
+ case BEHIND:
+ case AHEAD:
+ if (a->from == to) {
+ freearc(nfa, a);
+ }
+ break;
+ }
+ }
+ /*
* First, clone to state if necessary to avoid other inarcs.
*/
Index: tests/regexp.test
===================================================================
RCS file: /cvsroot/tcl/tcl/tests/regexp.test,v
retrieving revision 1.27
diff -u -r1.27 regexp.test
--- tests/regexp.test 10 May 2005 18:35:23 -0000 1.27
+++ tests/regexp.test 15 Nov 2007 21:31:15 -0000
@@ -655,6 +655,11 @@
} {{0 -1} {2 1} {4 3}}
+test regexp-22.1 {Bug 1810038} {
+ regexp ($|^X)* {}
+} 1
+
+
# cleanup
::tcltest::cleanupTests
return
