unitialized data in populate_record_worker

Hi,

while testing a patch I ran valgrind over a recent checkout, and it spit
out the following:
==14792== Conditional jump or move depends on uninitialised value(s)
==14792==    at 0x7F8A30: populate_record_worker (jsonfuncs.c:1459)
==14792==    by 0x7F8451: json_to_record (jsonfuncs.c:1280)
==14792==    by 0x632EF2: ExecMakeTableFunctionResult (execQual.c:2164)
==14792==    by 0x65387B: FunctionNext (nodeFunctionscan.c:94)
==14792==    by 0x63A209: ExecScanFetch (execScan.c:82)
==14792==    by 0x63A278: ExecScan (execScan.c:132)
==14792==    by 0x653BD0: ExecFunctionScan (nodeFunctionscan.c:266)
==14792==    by 0x62F2B6: ExecProcNode (execProcnode.c:426)
==14792==    by 0x62D070: ExecutePlan (execMain.c:1474)
==14792==    by 0x62B1CE: standard_ExecutorRun (execMain.c:308)
==14792==    by 0x62B045: ExecutorRun (execMain.c:256)
==14792==    by 0x7850B6: PortalRunSelect (pquery.c:946)

which looks accurate, my_extra->columns doesn't look initialized.

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
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