From 014a4fda54cb6897ed54ea9c44376db3459fc46e Mon Sep 17 00:00:00 2001 From: Kasumi Hanazuki Date: Thu, 13 Aug 2020 02:26:09 +0000 Subject: rb_str_{index,rindex}_m: Handle /\K/ in pattern When the pattern Regexp given to String#index and String#rindex contain a /\K/ (lookbehind) operator, these methods return the position where the beginning of the lookbehind pattern matches, while they are expected to return the position where the \K matches. ``` # without patch "abcdbce".index(/b\Kc/) # => 1 "abcdbce".rindex(/b\Kc/) # => 4 ``` This patch fixes this problem by using BEG(0) instead of the return value of rb_reg_search. ``` # with patch "abcdbce".index(/b\Kc/) # => 2 "abcdbce".rindex(/b\Kc/) # => 5 ``` Fixes [Bug #17118] --- string.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) (limited to 'string.c') diff --git a/string.c b/string.c index e1c6e54456..e984330b9a 100644 --- a/string.c +++ b/string.c @@ -3676,8 +3676,14 @@ rb_str_index_m(int argc, VALUE *argv, VALUE str) pos = str_offset(RSTRING_PTR(str), RSTRING_END(str), pos, rb_enc_check(str, sub), single_byte_optimizable(str)); - pos = rb_reg_search(sub, str, pos, 0); - pos = rb_str_sublen(str, pos); + if (rb_reg_search(sub, str, pos, 0) < 0) { + return Qnil; + } else { + VALUE match = rb_backref_get(); + struct re_registers *regs = RMATCH_REGS(match); + pos = rb_str_sublen(str, BEG(0)); + return LONG2NUM(pos); + } } else { StringValue(sub); @@ -3827,9 +3833,12 @@ rb_str_rindex_m(int argc, VALUE *argv, VALUE str) pos = str_offset(RSTRING_PTR(str), RSTRING_END(str), pos, enc, single_byte_optimizable(str)); - pos = rb_reg_search(sub, str, pos, 1); - pos = rb_str_sublen(str, pos); - if (pos >= 0) return LONG2NUM(pos); + if (rb_reg_search(sub, str, pos, 1) >= 0) { + VALUE match = rb_backref_get(); + struct re_registers *regs = RMATCH_REGS(match); + pos = rb_str_sublen(str, BEG(0)); + return LONG2NUM(pos); + } } else { StringValue(sub); -- cgit v1.2.3