Em seg., 12 de jul. de 2021 às 05:20, Heikki Linnakangas <hlinnaka@iki.fi> escreveu:
On 12/07/2021 02:34, Ranier Vilela wrote: > If it is not possible, know the upper limits, before the loop. > It is necessary to do this inside the loop.
> @@ -49,10 +47,14 @@ _bt_restore_page(Page page, char *from, int len) > * To get the items back in the original order, we add them to the page in > * reverse. To figure out where one tuple ends and another begins, we > * have to scan them in forward order first. > + * Check the array upper limit to not overtake him. > */ > i = 0; > - while (from < end) > + while (from < end && i <= MaxIndexTuplesPerPage) > { > + IndexTupleData itupdata; > + Size itemsz; > + > /* > * As we step through the items, 'from' won't always be properly > * aligned, so we need to use memcpy(). Further, we use Item (which
If we bother checking it, we should throw an error if the check fails, not just silently soldier on. Also, shouldn't it be '<', not '<='?
Should be '<', you are right.
In general though, we don't do much checking on WAL records, we assume that the contents are sane. It would be nice to add more checks and make WAL redo routines more robust to corrupt records, but this seems like an odd place to start.
If WAL records can't be corrupted at _bt_restore_page, that's ok, it's safe.
I committed the removal of bogus assignment to 'from'. Thanks!