Missing total item count sends <List> to re-render loop

[kiirala]

Originally reported on other issue, these likely share the same root cause: #4025 (comment)

What you were expecting:

Before react-admin 3.0, would render the available data regardless of the total item count.

What happened instead:

In react-admin 3.0, if total item count somehow ends up as NaN, the data is not shown. Instead, we get "Error: Too many re-renders."

Steps to reproduce:

I was using ra-data-simple-rest with a backend that provides content-range headers, but not total count of available items. For example: Content-Range: thingamajings 0-24/*

Next, ra-data-simple-rest fetches the total using total: parseInt(headers.get('content-range').split('/').pop(), 10). This results in total=NaN

Last important bit is in useQueryWithStore in ra-core: this checks for state updates using if (!isEqual(state.data, data) || state.total !== total) ... However, since total=NaN the second condition is never true. It thus always appears as if the fetched data has been updated, so this code attempts to update the related component. I don't have full details, how, but this results in scheduling updates over and over again, until the "Too many re-renders" check stops the loop.

Sample code

Example code here, based on the simple example: https://codesandbox.io/s/simple-t03vd
The only edits there are to dataProvider.js, to make it provide the problematic data.

Environment

• React-admin version: 3.0.1
• Last version that did not exhibit the issue (if applicable): 2.8.3
• React version: 16.12.0
• Browser: Chrome 78