diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index 6a27ef4140..b019bc1a0d 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -5722,6 +5722,17 @@ l4: goto out_locked; } + /* + * Also check Xmin: if this tuple was created by an aborted + * (sub)transaction, then we already locked the last live one in the + * chain, thus we're done, so return success. + */ + if (TransactionIdDidAbort(HeapTupleHeaderGetXmin(mytup.t_data))) + { + UnlockReleaseBuffer(buf); + return HeapTupleMayBeUpdated; + } + old_infomask = mytup.t_data->t_infomask; old_infomask2 = mytup.t_data->t_infomask2; xmax = HeapTupleHeaderGetRawXmax(mytup.t_data); diff --git a/src/test/regress/expected/combocid.out b/src/test/regress/expected/combocid.out index b63894c283..17eb94a8ff 100644 --- a/src/test/regress/expected/combocid.out +++ b/src/test/regress/expected/combocid.out @@ -140,3 +140,30 @@ SELECT ctid,cmin,* FROM combocidtest; (0,6) | 0 | 444 (3 rows) +-- test for bug reported in +-- CABRT9RC81YUf1=jsmWopcKJEro=VoeG2ou6sPwyOUTx_qteRsg@mail.gmail.com +CREATE TABLE IF NOT EXISTS testcase( + id int PRIMARY KEY, + balance numeric +); +INSERT INTO testcase VALUES (1, 0); +BEGIN; +SELECT * FROM testcase WHERE testcase.id = 1 FOR UPDATE; + id | balance +----+--------- + 1 | 0 +(1 row) + +UPDATE testcase SET balance = balance + 400 WHERE id=1; +SAVEPOINT subxact; +UPDATE testcase SET balance = balance - 100 WHERE id=1; +ROLLBACK TO SAVEPOINT subxact; +-- should return one tuple +SELECT * FROM testcase WHERE id = 1 FOR UPDATE; + id | balance +----+--------- + 1 | 400 +(1 row) + +ROLLBACK; +DROP TABLE testcase; diff --git a/src/test/regress/sql/combocid.sql b/src/test/regress/sql/combocid.sql index f24ac6b01a..4faea36f41 100644 --- a/src/test/regress/sql/combocid.sql +++ b/src/test/regress/sql/combocid.sql @@ -91,3 +91,21 @@ SELECT ctid,cmin,* FROM combocidtest; COMMIT; SELECT ctid,cmin,* FROM combocidtest; + +-- test for bug reported in +-- CABRT9RC81YUf1=jsmWopcKJEro=VoeG2ou6sPwyOUTx_qteRsg@mail.gmail.com +CREATE TABLE IF NOT EXISTS testcase( + id int PRIMARY KEY, + balance numeric +); +INSERT INTO testcase VALUES (1, 0); +BEGIN; +SELECT * FROM testcase WHERE testcase.id = 1 FOR UPDATE; +UPDATE testcase SET balance = balance + 400 WHERE id=1; +SAVEPOINT subxact; +UPDATE testcase SET balance = balance - 100 WHERE id=1; +ROLLBACK TO SAVEPOINT subxact; +-- should return one tuple +SELECT * FROM testcase WHERE id = 1 FOR UPDATE; +ROLLBACK; +DROP TABLE testcase;