From 9305fa136918010fab36c09e7174c5a45b422141 Mon Sep 17 00:00:00 2001
From: Maxime Coste <mawww@kakoune.org>
Date: Mon, 9 Oct 2017 11:20:05 +0800
Subject: [PATCH] Regex: Fix lookaround use in moon.kak

(?=[A-Z]\w*) is strictly the same as (?=[A-Z]) as \w* will always
at least match an empty string.
---
 src/regex_impl.cc | 4 ++--
 src/regex_impl.hh | 7 +++++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/regex_impl.cc b/src/regex_impl.cc
index 2e3b9ccf..6673695d 100644
--- a/src/regex_impl.cc
+++ b/src/regex_impl.cc
@@ -1067,13 +1067,13 @@ auto test_regex = UnitTest{[]{
     }
 
     {
-        TestVM<> vm{R"((?!foo)...)"};
+        TestVM<> vm{R"((?!f[oa]o)...)"};
         kak_assert(not vm.exec("foo"));
         kak_assert(vm.exec("qux"));
     }
 
     {
-        TestVM<> vm{R"(...(?<=foo))"};
+        TestVM<> vm{R"(...(?<=f.o))"};
         kak_assert(vm.exec("foo"));
         kak_assert(not vm.exec("qux"));
     }
diff --git a/src/regex_impl.hh b/src/regex_impl.hh
index cb5a53be..d18de8a1 100644
--- a/src/regex_impl.hh
+++ b/src/regex_impl.hh
@@ -388,8 +388,11 @@ private:
             auto cp = (look_direction == MatchDirection::Forward ? *pos : *(pos-1)), ref = *it;
             if (ref == 0xF000)
             {} // any character matches
-            else if (ref > 0xF0000 and ref <= 0xFFFFD and not m_program.matchers[ref - 0xF0001](cp))
-                return false;
+            else if (ref > 0xF0000 and ref <= 0xFFFFD)
+            {
+                if (not m_program.matchers[ref - 0xF0001](cp))
+                    return false;
+            }
             else if (ref != cp)
                 return false;