merge r47598 partially. extracted commits are as follows. [Bug #9728]

https://github.com/k-takata/Onigmo/commit/15ddec6d18e27fdc1988236764e766fd5892ecf5


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@47954 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 1 deletions

diff --git a/regexec.c b/regexec.c
index 973d3eac00..6c5ba57760 100644
--- a/regexec.c
+++ b/regexec.c
@@ -4184,7 +4184,7 @@ onig_search_gpos(regex_t* reg, const UChar* str, const UChar* end,
             prev = s;
             s += enclen(reg->enc, s, end);
 
-            if ((reg->anchor & ANCHOR_LOOK_BEHIND) == 0) {
+            if ((reg->anchor & (ANCHOR_LOOK_BEHIND | ANCHOR_PREC_READ_NOT)) == 0) {
               while (!ONIGENC_IS_MBC_NEWLINE_EX(reg->enc, prev, str, end, reg->options, 0)
                      && s < range) {
                 prev = s;