Nathan Bossart <nathandbossart@gmail.com> writes: > On Mon, Jul 25, 2022 at 04:40:51PM +0200, Martin Kalcher wrote: >> +SELECT trim_array(ARRAY[]::int[], 1); -- fail >> +ERROR: number of elements to trim must be between 0 and 0 > Can we improve the error message? Maybe it should look something like > ERROR: number of elements to trim must be 0 > for this case. Hmm, I'm unexcited about making our long-suffering translators deal with another translatable string for such a corner case. I think it's fine as-is. A bigger problem is that a little further down, there's an equally unprotected reference to ARR_LBOUND(v)[0]. Now, the fact that that expression computes garbage doesn't matter too much, because AFAICS if the array is zero-D then array_get_slice is going to exit at if (ndim < nSubscripts || ndim <= 0 || ndim > MAXDIM) return PointerGetDatum(construct_empty_array(elemtype)); without ever examining its upperIndx[] argument. However, once we put in a test case covering this behavior, I bet that valgrind-using buildfarm animals will start to bleat about the invalid memory access. I think the easiest fix is like if (ARR_NDIM(v) > 0) { upper[0] = ARR_LBOUND(v)[0] + array_length - n - 1; upperProvided[0] = true; } It'd be good to get this fix into next week's minor releases, so I'll go push it. regards, tom lane