tsvector concatenation - backend crash

Hi

Attached SQL files gives (at least in my hands) a reliable backend crash
with this stacktrace .. reproduced on both 9.0.4 and HEAD. I'm sorry
I cannot provide a more trimmed down set of vectors the reproduces the
bug, thus
the "obsfucated" dataset. But even deleting single terms in the vectors make
the bug go away.

*** glibc detected *** postgres: jk jk [local] SELECT: corrupted
double-linked list: 0x0000000002279f80 ***
======= Backtrace: =========
/lib/libc.so.6(+0x775b6)[0x7fe4db4b25b6]
/lib/libc.so.6(+0x7aa25)[0x7fe4db4b5a25]
/lib/libc.so.6(cfree+0x73)[0x7fe4db4b8e83]
postgres: jk jk [local] SELECT[0x710de5]
postgres: jk jk [local] SELECT(MemoryContextReset+0x2a)[0x71119a]
postgres: jk jk [local] SELECT(ExecScan+0x4a)[0x57887a]
postgres: jk jk [local] SELECT(ExecProcNode+0x238)[0x571708]
postgres: jk jk [local] SELECT(standard_ExecutorRun+0xd2)[0x5705e2]
postgres: jk jk [local] SELECT[0x63c627]
postgres: jk jk [local] SELECT(PortalRun+0x248)[0x63d948]
postgres: jk jk [local] SELECT[0x639fdb]
postgres: jk jk [local] SELECT(PostgresMain+0x547)[0x63af97]
postgres: jk jk [local] SELECT[0x5fb959]
postgres: jk jk [local] SELECT(PostmasterMain+0xa97)[0x5fe137]
postgres: jk jk [local] SELECT(main+0x490)[0x59f4d0]
/lib/libc.so.6(__libc_start_main+0xfd)[0x7fe4db459c4d]
postgres: jk jk [local] SELECT[0x45d569]
======= Memory map: ========
00400000-008d6000 r-xp 00000000 08:01 4071141
/tmp/pgsql/bin/postgres
00ad5000-00ad6000 r--p 004d5000 08:01 4071141
/tmp/pgsql/bin/postgres
00ad6000-00ae2000 rw-p 004d6000 08:01 4071141
/tmp/pgsql/bin/postgres
00ae2000-00b43000 rw-p 00000000 00:00 0
0215d000-0227e000 rw-p 00000000 00:00 0
[heap]
7fe4d4000000-7fe4d4021000 rw-p 00000000 00:00 0
7fe4d4021000-7fe4d8000000 ---p 00000000 00:00 0
7fe4d908f000-7fe4d90a5000 r-xp 00000000 08:01 4194383
/lib/libgcc_s.so.1
7fe4d90a5000-7fe4d92a4000 ---p 00016000 08:01 4194383
/lib/libgcc_s.so.1
7fe4d92a4000-7fe4d92a5000 r--p 00015000 08:01 4194383
/lib/libgcc_s.so.1
7fe4d92a5000-7fe4d92a6000 rw-p 00016000 08:01 4194383
/lib/libgcc_s.so.1
7fe4d92c1000-7fe4d9342000 rw-p 00000000 00:00 0
7fe4d9342000-7fe4db22e000 rw-s 00000000 00:04 8716337
/SYSV0052ea91 (deleted)
7fe4db22e000-7fe4db23a000 r-xp 00000000 08:01 4194415
/lib/libnss_files-2.11.1.so
7fe4db23a000-7fe4db439000 ---p 0000c000 08:01 4194415
/lib/libnss_files-2.11.1.so
7fe4db439000-7fe4db43a000 r--p 0000b000 08:01 4194415
/lib/libnss_files-2.11.1.so
7fe4db43a000-7fe4db43b000 rw-p 0000c000 08:01 4194415
/lib/libnss_files-2.11.1.so
7fe4db43b000-7fe4db5b5000 r-xp 00000000 08:01 4194349
/lib/libc-2.11.1.so
7fe4db5b5000-7fe4db7b4000 ---p 0017a000 08:01 4194349
/lib/libc-2.11.1.so
7fe4db7b4000-7fe4db7b8000 r--p 00179000 08:01 4194349
/lib/libc-2.11.1.so
7fe4db7b8000-7fe4db7b9000 rw-p 0017d000 08:01 4194349
/lib/libc-2.11.1.so
7fe4db7b9000-7fe4db7be000 rw-p 00000000 00:00 0
7fe4db7be000-7fe4db840000 r-xp 00000000 08:01 4194398
/lib/libm-2.11.1.so
7fe4db840000-7fe4dba3f000 ---p 00082000 08:01 4194398
/lib/libm-2.11.1.so
7fe4dba3f000-7fe4dba40000 r--p 00081000 08:01 4194398
/lib/libm-2.11.1.so
7fe4dba40000-7fe4dba41000 rw-p 00082000 08:01 4194398
/lib/libm-2.11.1.so
7fe4dba41000-7fe4dba43000 r-xp 00000000 08:01 4194363
/lib/libdl-2.11.1.so
7fe4dba43000-7fe4dbc43000 ---p 00002000 08:01 4194363
/lib/libdl-2.11.1.so
7fe4dbc43000-7fe4dbc44000 r--p 00002000 08:01 4194363
/lib/libdl-2.11.1.so
7fe4dbc44000-7fe4dbc45000 rw-p 00003000 08:01 4194363
/lib/libdl-2.11.1.so
7fe4dbc45000-7fe4dbc65000 r-xp 00000000 08:01 4194325
/lib/ld-2.11.1.so
7fe4dbc85000-7fe4dbce7000 rw-p 00000000 00:00 0
7fe4dbce7000-7fe4dbd26000 r--p 00000000 08:01 5512971
/usr/lib/locale/en_DK.utf8/LC_CTYPE
7fe4dbd26000-7fe4dbe44000 r--p 00000000 08:01 5512650
/usr/lib/locale/en_DK.utf8/LC_COLLATE
7fe4dbe44000-7fe4dbe47000 rw-p 00000000 00:00 0
7fe4dbe58000-7fe4dbe59000 r--p 00000000 08:01 5515083
/usr/lib/locale/en_DK.utf8/LC_TIME
7fe4dbe59000-7fe4dbe5a000 r--p 00000000 08:01 5515084
/usr/lib/locale/en_DK.utf8/LC_MONETARY
7fe4dbe5a000-7fe4dbe5b000 r--p 00000000 08:01 5640299
/usr/lib/locale/en_DK.utf8/LC_MESSAGES/SYS_LC_MESSAGES
7fe4dbe5b000-7fe4dbe62000 r--s 00000000 08:01 5511621
/usr/lib/gconv/gconv-modules.cache
7fe4dbe62000-7fe4dbe64000 rw-p 00000000 00:00 0
7fe4dbe64000-7fe4dbe65000 r--p 0001f000 08:01 4194325
/lib/ld-2.11.1.so
7fe4dbe65000-7fe4dbe66000 rw-p 00020000 08:01 4194325
/lib/ld-2.11.1.so
7fe4dbe66000-7fe4dbe67000 rw-p 00000000 00:00 0
7ffffaedd000-7ffffaf0d000 rw-p 00000000 00:00 0
[stack]
7ffffaf8b000-7ffffaf8c000 r-xp 00000000 00:00 0
[vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0
[vsyscall]
LOG:  server process (PID 21514) was terminated by signal 6: Aborted

Thanks.
Jesper