3 files changed, 31 insertions, 9 deletions
diff --git a/src/backend/regex/regexec.c b/src/backend/regex/regexec.c
index 3748a9c1714..78ebdee39e4 100644
--- a/src/backend/regex/regexec.c
+++ b/src/backend/regex/regexec.c
@@ -487,19 +487,21 @@ cfindloop(struct vars * v,
 					*coldp = cold;
 					return er;
 				}
-				if ((shorter) ? end == estop : end == begin)
-				{
-					/* no point in trying again */
-					*coldp = cold;
-					return REG_NOMATCH;
-				}
-				/* go around and try again */
+				/* try next shorter/longer match with same begin point */
 				if (shorter)
+				{
+					if (end == estop)
+						break;	/* NOTE BREAK OUT */
 					estart = end + 1;
+				}
 				else
+				{
+					if (end == begin)
+						break;	/* NOTE BREAK OUT */
 					estop = end - 1;
-			}
-		}
+				}
+			}					/* end loop over endpoint positions */
+		}						/* end loop over beginning positions */
 	} while (close < v->stop);
 
 	*coldp = cold;
diff --git a/src/test/regress/expected/regex.out b/src/test/regress/expected/regex.out
index 757f2a4028a..df39ef937dd 100644
--- a/src/test/regress/expected/regex.out
+++ b/src/test/regress/expected/regex.out
@@ -173,3 +173,18 @@ select 'a' ~ '((((((a+|)+|)+|)+|)+|)+|)';
  t
 (1 row)
 
+-- Test backref in combination with non-greedy quantifier
+-- https://core.tcl.tk/tcl/tktview/6585b21ca8fa6f3678d442b97241fdd43dba2ec0
+select 'Programmer' ~ '(\w).*?\1' as t;
+ t 
+---
+ t
+(1 row)
+
+select regexp_matches('Programmer', '(\w)(.*?\1)', 'g');
+ regexp_matches 
+----------------
+ {r,ogr}
+ {m,m}
+(2 rows)
+
diff --git a/src/test/regress/sql/regex.sql b/src/test/regress/sql/regex.sql
index 1426562119a..e5f690263b9 100644
--- a/src/test/regress/sql/regex.sql
+++ b/src/test/regress/sql/regex.sql
@@ -41,3 +41,8 @@ select 'a' ~ '($|^)*';
 -- Test for infinite loop in fixempties() (Tcl bugs 3604074, 3606683)
 select 'a' ~ '((((((a)*)*)*)*)*)*';
 select 'a' ~ '((((((a+|)+|)+|)+|)+|)+|)';
+
+-- Test backref in combination with non-greedy quantifier
+-- https://core.tcl.tk/tcl/tktview/6585b21ca8fa6f3678d442b97241fdd43dba2ec0
+select 'Programmer' ~ '(\w).*?\1' as t;
+select regexp_matches('Programmer', '(\w)(.*?\1)', 'g');