Add overflow checks to int4 and int8 versions of generate_series().

The previous code went into an infinite loop after overflow.  In fact,
an overflow is not really an error; it just means that the current
value is the last one we need to return.  So, just arrange to stop
immediately when overflow is detected.

Back-patch all the way.
This commit is contained in:
Robert Haas 2011-06-17 14:28:45 -04:00
parent bf347c60bd
commit 062780ec35
2 changed files with 8 additions and 0 deletions

View File

@ -1382,6 +1382,10 @@ generate_series_step_int4(PG_FUNCTION_ARGS)
/* increment current in preparation for next iteration */
fctx->current += fctx->step;
/* if next-value computation overflows, this is the final result */
if (SAMESIGN(result, fctx->step) && !SAMESIGN(result, fctx->current))
fctx->step = 0;
/* do when there is more left to send */
SRF_RETURN_NEXT(funcctx, Int32GetDatum(result));
}

View File

@ -1410,6 +1410,10 @@ generate_series_step_int8(PG_FUNCTION_ARGS)
/* increment current in preparation for next iteration */
fctx->current += fctx->step;
/* if next-value computation overflows, this is the final result */
if (SAMESIGN(result, fctx->step) && !SAMESIGN(result, fctx->current))
fctx->step = 0;
/* do when there is more left to send */
SRF_RETURN_NEXT(funcctx, Int64GetDatum(result));
}