From 062780ec35f9db630e784b27a54440017df77531 Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Fri, 17 Jun 2011 14:28:45 -0400 Subject: [PATCH] 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. --- src/backend/utils/adt/int.c | 4 ++++ src/backend/utils/adt/int8.c | 4 ++++ 2 files changed, 8 insertions(+) diff --git a/src/backend/utils/adt/int.c b/src/backend/utils/adt/int.c index 019fcaaa36..a367421f82 100644 --- a/src/backend/utils/adt/int.c +++ b/src/backend/utils/adt/int.c @@ -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)); } diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c index 451916480c..2e74482979 100644 --- a/src/backend/utils/adt/int8.c +++ b/src/backend/utils/adt/int8.c @@ -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)); }