Re: BUG #2594: Gin Indexes cause server to crash on Windows

"Gin Indexes cause server to crash on Windows" <cfis@savagexi.com> writes:
> CREATE TABLE test (
>   vector tsvector NOT NULL
> );
> CREATE INDEX idx_test_vector ON test USING gin (vector);
> server closed the connection unexpectedly

It appears that building a gin index on an empty table fails on any
platform.  I get a null pointer dereference with the following stack trace

(gdb) bt
#0  ginGetEntry (accum=0x7b03bc90, value=0x7b03bcd8, n=0x7b03bcdc)
    at ginbulk.c:251
#1  0x15f994 in ginbuild (fcinfo=0x40104d80) at gininsert.c:316
#2  0x357a70 in OidFunctionCall3 (functionId=1074810240, arg1=1074604248,
    arg2=1074631680, arg3=1074717032) at fmgr.c:1460
#3  0x17cb4c in index_build (heapRelation=0x400ee168,
    indexRelation=0x400d9400, indexInfo=0x400ee168, isprimary=0 '\000')
    at index.c:1281
#4  0x17c1a0 in index_create (heapRelationId=83433,
    indexRelationName=0x400b1698 "idx_test_vector", indexRelationId=95941,
    indexInfo=0x400ee168, accessMethodObjectId=2742, tableSpaceId=0,
    classObjectId=0x400fa5b0, reloptions=0, isprimary=0, isconstraint=0,
    allow_system_table_mods=0, skip_build=0 '\000', concurrent=0)
    at index.c:782
#5  0x1d1da0 in DefineIndex (heapRelation=0x400b16d0,
    indexRelationName=0x400b1698 "idx_test_vector", indexRelationId=0,
    accessMethodName=0x400b1700 "gin", tableSpaceName=0x0,
    attributeList=0x400b1768, predicate=0x0, rangetable=0x0, options=0x0,
    unique=0 '\000', primary=0 '\000', isconstraint=0 '\000',
    is_alter_table=0 '\000', check_rights=1, skip_build=0 '\000',
    quiet=0 '\000', concurrent=0 '\000') at indexcmds.c:439

and

(gdb) p *accum
$1 = {ginstate = 0x7b03bc18, entries = 0x0, maxdepth = 1, stack = 0x40104d78,
  stackpos = 0, allocatedMemory = 0, length = 1074717032, entryallocator = 0x0}

so it would seem that ginGetEntry() has overlooked the case that there
are no entries.

            regards, tom lane