From: Justin Viiret <justin.viiret@intel.com>
Date: Mon, 6 Mar 2017 03:15:56 +0000 (+1100)
Subject: ng: check can_never_match before validate_fuzzy
X-Git-Tag: v4.5.0^2~195
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5edecbf539fb3b979f45c5832ef8c04c07bc085e;p=thirdparty%2Fvectorscan.git

ng: check can_never_match before validate_fuzzy
---

diff --git a/src/nfagraph/ng.cpp b/src/nfagraph/ng.cpp
index 9453aae9..2f6d8cd7 100644
--- a/src/nfagraph/ng.cpp
+++ b/src/nfagraph/ng.cpp
@@ -330,6 +330,10 @@ bool NG::addGraph(NGWrapper &w) {
     /* ensure utf8 starts at cp boundary */
     ensureCodePointStart(rm, w);
 
+    if (can_never_match(w)) {
+        throw CompileError(w.expressionIndex, "Pattern can never match.");
+    }
+
     // validate graph's suitability for fuzzing before resolving asserts
     validate_fuzzy_compile(w, w.edit_distance, w.utf8, cc.grey);
 
diff --git a/unit/hyperscan/bad_patterns.txt b/unit/hyperscan/bad_patterns.txt
index 09a2f7e1..3d6d9db9 100644
--- a/unit/hyperscan/bad_patterns.txt
+++ b/unit/hyperscan/bad_patterns.txt
@@ -141,3 +141,4 @@
 144:/abc\b/{edit_distance=1} #Zero-width assertions are disallowed for approximate matching.
 145:/abc/8{edit_distance=1} #UTF-8 is disallowed for approximate matching.
 146:/(*UTF8)abc/{edit_distance=1} #UTF-8 is disallowed for approximate matching.
+147:/\b\BMYBt/s{edit_distance=1} #Pattern can never match.