diff options
| -rw-r--r-- | ChangeLog | 3 | ||||
| -rw-r--r-- | generic/regc_nfa.c | 41 | ||||
| -rw-r--r-- | tests/regexp.test | 7 |
3 files changed, 50 insertions, 1 deletions
@@ -1,5 +1,8 @@ 2007-11-15 Don Porter <dgp@users.sourceforge.net> + * generic/regc_nfa.c: Fixed infinite loop in the regexp compiler. + [Bug 1810038]. + * generic/regc_nfa.c: Corrected looping logic in fixempties() to avoid wasting time walking a list of dead states. [Bug 1832612] diff --git a/generic/regc_nfa.c b/generic/regc_nfa.c index c5d7bc9..741887f 100644 --- a/generic/regc_nfa.c +++ b/generic/regc_nfa.c @@ -859,6 +859,25 @@ pull( } /* + * 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 '$': + case BEHIND: + case AHEAD: + if (from == a->to) { + freearc(nfa, a); + } + break; + } + } + + /* * First, clone from state if necessary to avoid other outarcs. */ @@ -997,6 +1016,28 @@ push( } /* + * DGP 2007-11-15: Here we duplicate the same protections as appear + * in pull() above to avoid troubles with cloning a state with a + * circular constraint on its list of ins. It is not clear whether + * this is necessary, or is protecting against a "can't happen". + * Any test case that actually leads to a freearc() call here would + * be a welcome addition to the test suite. + */ + + for (a = to->ins; a != NULL; a = nexta) { + nexta = a->inchain; + switch (a->type) { + case '^': + case '$': + case BEHIND: + case AHEAD: + if (a->from == to) { + freearc(nfa, a); + } + break; + } + } + /* * First, clone to state if necessary to avoid other inarcs. */ diff --git a/tests/regexp.test b/tests/regexp.test index 03efa04..d0413c8 100644 --- a/tests/regexp.test +++ b/tests/regexp.test @@ -11,7 +11,7 @@ # See the file "license.terms" for information on usage and redistribution # of this file, and for a DISCLAIMER OF ALL WARRANTIES. # -# RCS: @(#) $Id: regexp.test,v 1.27 2005/05/10 18:35:23 kennykb Exp $ +# RCS: @(#) $Id: regexp.test,v 1.28 2007/11/15 21:38:50 dgp Exp $ if {[lsearch [namespace children] ::tcltest] == -1} { package require tcltest 2 @@ -655,6 +655,11 @@ test regexp-21.13 {multiple matches handle newlines} { } {{0 -1} {2 1} {4 3}} +test regexp-22.1 {Bug 1810038} { + regexp ($|^X)* {} +} 1 + + # cleanup ::tcltest::cleanupTests return |