diff --git a/src/backend/utils/adt/regexp.c b/src/backend/utils/adt/regexp.c
index e3a852769f..7463c0dd2f 100644
--- a/src/backend/utils/adt/regexp.c
+++ b/src/backend/utils/adt/regexp.c
@@ -936,6 +936,7 @@ setup_regexp_matches(text *orig_str, text *pattern, text *flags,
 	int			array_len;
 	int			array_idx;
 	int			prev_match_end;
+	int			prev_valid_match_end;
 	int			start_search;
 	int			maxlen = 0;		/* largest fetch length in characters */
 
@@ -991,6 +992,7 @@ setup_regexp_matches(text *orig_str, text *pattern, text *flags,
 
 	/* search for the pattern, perhaps repeatedly */
 	prev_match_end = 0;
+	prev_valid_match_end = 0;
 	start_search = 0;
 	while (RE_wchar_execute(cpattern, wide_str, wide_len, start_search,
 							pmatch_len, pmatch))
@@ -1043,13 +1045,15 @@ setup_regexp_matches(text *orig_str, text *pattern, text *flags,
 			matchctx->nmatches++;
 
 			/*
-			 * check length of unmatched portion between end of previous match
-			 * and start of current one
+			 * check length of unmatched portion between end of previous valid
+			 * (nondegenerate, or degenerate but not ignored) match and start
+			 * of current one
 			 */
 			if (fetching_unmatched &&
 				pmatch[0].rm_so >= 0 &&
-				(pmatch[0].rm_so - prev_match_end) > maxlen)
-				maxlen = (pmatch[0].rm_so - prev_match_end);
+				(pmatch[0].rm_so - prev_valid_match_end) > maxlen)
+				maxlen = (pmatch[0].rm_so - prev_valid_match_end);
+			prev_valid_match_end = pmatch[0].rm_eo;
 		}
 		prev_match_end = pmatch[0].rm_eo;
 
@@ -1075,8 +1079,8 @@ setup_regexp_matches(text *orig_str, text *pattern, text *flags,
 	 * input string
 	 */
 	if (fetching_unmatched &&
-		(wide_len - prev_match_end) > maxlen)
-		maxlen = (wide_len - prev_match_end);
+		(wide_len - prev_valid_match_end) > maxlen)
+		maxlen = (wide_len - prev_valid_match_end);
 
 	/*
 	 * Keep a note of the end position of the string for the benefit of
diff --git a/src/test/regress/expected/strings.out b/src/test/regress/expected/strings.out
index 19708c32fd..8e7470d1cb 100644
--- a/src/test/regress/expected/strings.out
+++ b/src/test/regress/expected/strings.out
@@ -674,6 +674,24 @@ SELECT regexp_split_to_array('123456','.');
  {"","","","","","",""}
 (1 row)
 
+SELECT regexp_split_to_array('123456','');
+ regexp_split_to_array 
+-----------------------
+ {1,2,3,4,5,6}
+(1 row)
+
+SELECT regexp_split_to_array('123456','(?:)');
+ regexp_split_to_array 
+-----------------------
+ {1,2,3,4,5,6}
+(1 row)
+
+SELECT regexp_split_to_array('1','');
+ regexp_split_to_array 
+-----------------------
+ {1}
+(1 row)
+
 -- errors
 SELECT foo, length(foo) FROM regexp_split_to_table('thE QUick bROWn FOx jUMPs ovEr The lazy dOG', 'e', 'zippy') AS foo;
 ERROR:  invalid regexp option: "z"
diff --git a/src/test/regress/sql/strings.sql b/src/test/regress/sql/strings.sql
index f9cfaeb44a..5e39458bd2 100644
--- a/src/test/regress/sql/strings.sql
+++ b/src/test/regress/sql/strings.sql
@@ -188,6 +188,9 @@ SELECT regexp_split_to_array('the quick brown fox jumps over the lazy dog', 'nom
 SELECT regexp_split_to_array('123456','1');
 SELECT regexp_split_to_array('123456','6');
 SELECT regexp_split_to_array('123456','.');
+SELECT regexp_split_to_array('123456','');
+SELECT regexp_split_to_array('123456','(?:)');
+SELECT regexp_split_to_array('1','');
 -- errors
 SELECT foo, length(foo) FROM regexp_split_to_table('thE QUick bROWn FOx jUMPs ovEr The lazy dOG', 'e', 'zippy') AS foo;
 SELECT regexp_split_to_array('thE QUick bROWn FOx jUMPs ovEr The lazy dOG', 'e', 'iz');