From d9d2140ea2af084b0455f84bc9948e3d639cdfb8 Mon Sep 17 00:00:00 2001
From: Maxime Coste <mawww@kakoune.org>
Date: Mon, 4 Feb 2019 17:33:29 +1100
Subject: [PATCH] Fix regex not always selecting the leftmost longest match

(Actually the rightmost longest match when searching backwards)

Fixes #2710
---
 src/regex_impl.cc | 6 ++++++
 src/regex_impl.hh | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/regex_impl.cc b/src/regex_impl.cc
index 8742e19cc..1ff73472b 100644
--- a/src/regex_impl.cc
+++ b/src/regex_impl.cc
@@ -1489,6 +1489,12 @@ auto test_regex = UnitTest{[]{
         kak_assert(StringView{vm.captures()[0], vm.captures()[1]}  == "baz");
     }
 
+    {
+        TestVM<RegexMode::Backward | RegexMode::Search> vm{R"(a[^\n]*\n|\n)"};
+        kak_assert(vm.exec("foo\nbar\nb", RegexExecFlags::None));
+        kak_assert(StringView{vm.captures()[0], vm.captures()[1]}  == "ar\n");
+    }
+
     {
         TestVM<> vm{R"(()*)"};
         kak_assert(not vm.exec(" "));
diff --git a/src/regex_impl.hh b/src/regex_impl.hh
index 962fbf611..ee374429d 100644
--- a/src/regex_impl.hh
+++ b/src/regex_impl.hh
@@ -510,7 +510,7 @@ private:
             forward ? utf8::to_next(pos, config.subject_end)
                     : utf8::to_previous(pos, config.subject_begin);
 
-            if (search)
+            if (search and not m_found_match)
             {
                 if (start_desc and m_threads.next_is_empty())
                     to_next_start(pos, config, *start_desc);