Make sure that capabilities for ngx_array are valid when the array is expanded.

[qwattash]

In case ngx_array are expanded and there is space for a new item in the existing pool, the array capability is not updated and will have the wrong length.

[brooksdavis]

There are more issues here. At a minimum, we need to check that elts is sufficiently aligned to permit the extension (possibly adding more than one element to allow it if the result won't be exactly representable), but if alignment is in play, there's a good chance that nalloc was set incorrectly in ngx_array_init since it should be rounded up as required.

[qwattash]

Good point, I'll have a stab at fixing those as well. I'm also not sure what is happening to the old elts pointer, which appears to never be free'd?

[brooksdavis]

Good point, I'll have a stab at fixing those as well. I'm also not sure what is happening to the old elts pointer, which appears to never be free'd?

Everything allocated by the pool is freed when the pool is freed (e.g. at the end of a transaction.) It's a bit odd that they don't call ngx_pfree, but maybe there are/were issues with stale references or maybe arrays are rarely big enough (since ngx_pfree only frees "large" objects and does so somewhat expensively.)