merge revision(s) 6d3f447aecfb56f7d3edbdf9cc68e748e150d7d8: [Backport #18631]

	Fix multiplex backreferencs near end of string in regexp match

	Idea from Jirka Marsik.

	Fixes [Bug #18631]
	---
	 regexec.c                | 6 ++++--
	 test/ruby/test_regexp.rb | 6 ++++++
	 2 files changed, 10 insertions(+), 2 deletions(-)

1 files changed, 4 insertions, 2 deletions

diff --git a/regexec.c b/regexec.c
index 8334b16e96..a7b948e99c 100644
--- a/regexec.c
+++ b/regexec.c
@@ -1176,11 +1176,13 @@ static int string_cmp_ic(OnigEncoding enc, int case_fold_flag,
 # define DATA_ENSURE_CHECK1    (s < right_range)
 # define DATA_ENSURE_CHECK(n)  (s + (n) <= right_range)
 # define DATA_ENSURE(n)        if (s + (n) > right_range) goto fail
+# define DATA_ENSURE_CONTINUE(n) if (s + (n) > right_range) continue
 # define ABSENT_END_POS        right_range
 #else
 # define DATA_ENSURE_CHECK1    (s < end)
 # define DATA_ENSURE_CHECK(n)  (s + (n) <= end)
 # define DATA_ENSURE(n)        if (s + (n) > end) goto fail
+# define DATA_ENSURE_CONTINUE(n) if (s + (n) > end) continue
 # define ABSENT_END_POS        end
 #endif /* USE_MATCH_RANGE_MUST_BE_INSIDE_OF_SPECIFIED_RANGE */
 
@@ -2643,7 +2645,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
 		  ? STACK_AT(mem_end_stk[mem])->u.mem.pstr
 		  : (UChar* )((void* )mem_end_stk[mem]));
 	  n = pend - pstart;
-	  DATA_ENSURE(n);
+	  DATA_ENSURE_CONTINUE(n);
 	  sprev = s;
 	  swork = s;
 	  STRING_CMP_VALUE(pstart, swork, n, is_fail);
@@ -2682,7 +2684,7 @@ match_at(regex_t* reg, const UChar* str, const UChar* end,
 		  ? STACK_AT(mem_end_stk[mem])->u.mem.pstr
 		  : (UChar* )((void* )mem_end_stk[mem]));
 	  n = pend - pstart;
-	  DATA_ENSURE(n);
+	  DATA_ENSURE_CONTINUE(n);
 	  sprev = s;
 	  swork = s;
 	  STRING_CMP_VALUE_IC(case_fold_flag, pstart, &swork, n, end, is_fail);