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Tom Lane
2e82d0b396
Normally nel == 0 works okay because the initial value of "last" will be less than "base"; but if "base" is zero then the calculation wraps around and we have a very large (unsigned) value for "last", so that the loop can be entered and we get a SIGSEGV on a bogus pointer. This is certainly the proximate cause of the recent reports of Windows builds crashing on 'infinity'::timestamp --- evidently, they're either not setting an active timezonetktbl, or setting an empty one. It's not yet clear to me why it's only happening on Windows and not happening on any buildfarm member. But even if that's due to some bug elsewhere, it seems wise for this function to not choke on the powerup values of timezonetktbl/sztimezonetktbl. I also changed the copy of this code in ecpglib, although I am not sure whether it's exposed to a similar hazard. Per report and stack trace from Richard Broersma.
src/interfaces/ecpg/README.dynSQL descriptor statements have the following shortcomings - input descriptors (USING DESCRIPTOR <name>) are not supported Reason: to fully support dynamic SQL the frontend/backend communication should change to recognize input parameters. Since this is not likely to happen in the near future and you can cover the same functionality with the existing infrastructure (using s[n]printf), I'll leave the work to someone else.