crash while decoding INSERT ON CONFLICT

Hi,

I got the following backtrace in a logical replication setup using 10.3.

Program terminated with signal 11, Segmentation fault.
#0  ReorderBufferCommit (rb=0xde2a08, xid=<value optimized out>,
commit_lsn=6211559254952, end_lsn=<value optimized out>,
commit_time=<value optimized out>, origin_id=<value optimized out>,
    origin_lsn=0) at reorderbuffer.c:1397
1397                                            change->action =
REORDER_BUFFER_CHANGE_INSERT;
Missing separate debuginfos, use: debuginfo-install
glibc-2.12-1.209.el6_9.2.x86_64 libxml2-2.7.6-21.el6_8.1.x86_64
zlib-1.2.3-29.el6.x86_64
(gdb) bt
#0  ReorderBufferCommit (rb=0xde2a08, xid=<value optimized out>,
commit_lsn=6211559254952, end_lsn=<value optimized out>,
commit_time=<value optimized out>, origin_id=<value optimized out>,
    origin_lsn=0) at reorderbuffer.c:1397
#1  0x00000000006bdd58 in DecodeCommit (ctx=0xdbe888, record=<value
optimized out>) at decode.c:611
#2  DecodeXactOp (ctx=0xdbe888, record=<value optimized out>) at decode.c:241
#3  LogicalDecodingProcessRecord (ctx=0xdbe888, record=<value
optimized out>) at decode.c:113
#4  0x00000000006d0754 in XLogSendLogical () at walsender.c:2781
#5  0x00000000006cf782 in WalSndLoop (send_data=0x6d0700
<XLogSendLogical>) at walsender.c:2149
#6  0x00000000006d1463 in StartLogicalReplication (cmd_string=<value
optimized out>) at walsender.c:1102
#7  exec_replication_command (cmd_string=<value optimized out>) at
walsender.c:1539
#8  0x00000000007182b9 in PostgresMain (argc=<value optimized out>,
argv=<value optimized out>, dbname=0xd368a8 "foo", username=<value
optimized out>) at postgres.c:4084
#9  0x00000000006ad27d in BackendRun (argc=<value optimized out>,
argv=<value optimized out>) at postmaster.c:4405
#10 BackendStartup (argc=<value optimized out>, argv=<value optimized
out>) at postmaster.c:4077
#11 ServerLoop (argc=<value optimized out>, argv=<value optimized
out>) at postmaster.c:1755
#12 PostmasterMain (argc=<value optimized out>, argv=<value optimized
out>) at postmaster.c:1363
#13 0x000000000062e5b0 in main (argc=3, argv=0xd04540) at main.c:228
(gdb) p change
$1 = (ReorderBufferChange *) 0x0
(gdb) p specinsert
$2 = (ReorderBufferChange *) 0x0

If my math is correct the lsn 6211559254952 is 5A6/3DC86BA8. The transaction is:

rmgr: Btree       len (rec/tot):   3795/ 11731, tx:  144441221, lsn:
5A6/3DC80B58, prev 5A6/3DC80B28, desc: SPLIT_R level 0, firstright
139, blkref #0: rel 1663/355309/54931968 blk 176078, blkref #1: rel
1663/355309/54931968 blk 223615, blkref #2: rel 1663/355309/54931968
blk 176079 FPW
rmgr: Btree       len (rec/tot):     61/  4481, tx:  144441221, lsn:
5A6/3DC83948, prev 5A6/3DC80B58, desc: INSERT_UPPER off 39, blkref #0:
rel 1663/355309/54931968 blk 176062 FPW, blkref #1: rel
1663/355309/54931968 blk 176078
rmgr: Btree       len (rec/tot):     72/    72, tx:  144441221, lsn:
5A6/3DC84AE8, prev 5A6/3DC83948, desc: INSERT_LEAF off 2, blkref #0:
rel 1663/355309/57252673 blk 218754
rmgr: Btree       len (rec/tot):     53/  7613, tx:  144441221, lsn:
5A6/3DC84B30, prev 5A6/3DC84AE8, desc: INSERT_LEAF off 129, blkref #0:
rel 1663/355309/57252674 blk 23008 FPW
rmgr: Btree       len (rec/tot):     64/    64, tx:  144441221, lsn:
5A6/3DC86908, prev 5A6/3DC84B30, desc: INSERT_LEAF off 71, blkref #0:
rel 1663/355309/57252998 blk 156099
rmgr: Btree       len (rec/tot):     72/    72, tx:  144441221, lsn:
5A6/3DC86948, prev 5A6/3DC86908, desc: INSERT_LEAF off 210, blkref #0:
rel 1663/355309/57253000 blk 219630
rmgr: Heap        len (rec/tot):     48/    48, tx:  144441221, lsn:
5A6/3DC86990, prev 5A6/3DC86948, desc: HEAP_CONFIRM off 5, blkref #0:
rel 1663/355309/382872 blk 5520503
rmgr: Heap        len (rec/tot):     54/    54, tx:  144441221, lsn:
5A6/3DC869C0, prev 5A6/3DC86990, desc: LOCK off 8: xid 144441221:
flags 0 LOCK_ONLY KEYSHR_LOCK , blkref #0: rel 1663/355309/42286702
blk 0
rmgr: Heap        len (rec/tot):     54/    54, tx:  144441221, lsn:
5A6/3DC869F8, prev 5A6/3DC869C0, desc: LOCK off 1: xid 144441221:
flags 0 LOCK_ONLY KEYSHR_LOCK , blkref #0: rel 1663/355309/42323652
blk 0
rmgr: Heap        len (rec/tot):     54/    54, tx:  144441221, lsn:
5A6/3DC86A30, prev 5A6/3DC869F8, desc: LOCK off 23: xid 144441221:
flags 0 LOCK_ONLY EXCL_LOCK , blkref #0: rel 1663/355309/382874 blk
4688787
rmgr: Heap        len (rec/tot):    211/   211, tx:  144441221, lsn:
5A6/3DC86A68, prev 5A6/3DC86A30, desc: HOT_UPDATE off 23 xmax
144441221 ; new off 24 xmax 144441221, blkref #0: rel
1663/355309/382874 blk 4688787
rmgr: Heap        len (rec/tot):     98/    98, tx:  144441221, lsn:
5A6/3DC86B40, prev 5A6/3DC86A68, desc: HOT_UPDATE off 32 xmax
144441221 ; new off 34 xmax 0, blkref #0: rel 1663/355309/39370447 blk
6284
rmgr: Transaction len (rec/tot):     46/    46, tx:  144441221, lsn:
5A6/3DC86BA8, prev 5A6/3DC86B40, desc: COMMIT 2018-05-21
10:26:05.830168 -03

which translates into something like:

BEGIN
INSERT INTO table_a ON CONFLICT
UPDATE table_b
UPDATE table_c
COMMIT

I don't have a test case yet. This is my next step after this report.
However, it seems to be related to INSERT ON CONFLICT decoding. Ideas?


-- 
   Euler Taveira                                   Timbira -
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