Error loading revisions history on new post

Creating a new post from the app does start a network call to retrieve History revisions for it. The backend replies with an error since it's a new post, available only locally, and the post ID passed to the server is 0.

2019-05-16 10:44:34.968 2451-2595/org.wordpress.android E/Volley: [1069] BasicNetwork.performRequest: Unexpected response code 400 for https://public-api.wordpress.com/rest/v1.1/sites/15592836/post/0/diffs/?locale=it_IT
2019-05-16 10:44:34.971 2451-2451/org.wordpress.android E/WordPress-API: Volley error on https://public-api.wordpress.com/rest/v1.1/sites/15592836/post/0/diffs/?locale=it_IT
    com.android.volley.ServerError
        at com.android.volley.toolbox.BasicNetwork.performRequest(BasicNetwork.java:179)
        at com.android.volley.NetworkDispatcher.run(NetworkDispatcher.java:114)
2019-05-16 10:44:34.974 2451-2451/org.wordpress.android D/WordPress-API: Dispatching action: PostAction-FETCHED_REVISIONS
2019-05-16 10:44:34.976 2451-2456/org.wordpress.android I/art: Do full code cache collection, code=507KB, data=501KB
2019-05-16 10:44:34.976 2451-2451/org.wordpress.android E/WordPress-API: An error occurred while fetching History revisions
2019-05-16 10:44:34.978 2451-2456/org.wordpress.android I/art: Starting a blocking GC JitCodeCache
2019-05-16 10:44:34.978 2451-2456/org.wordpress.android I/art: After code cache collection, code=449KB, data=392KB
2019-05-16 10:44:35.085 2451-2590/org.wordpress.android E/Volley: [1064] BasicNetwork.performRequest: Unexpected response code 400 for https://public-api.wordpress.com/rest/v1.1/sites/15592836/post/0/diffs/?locale=it_IT
2019-05-16 10:44:35.089 2451-2451/org.wordpress.android E/WordPress-API: Volley error on https://public-api.wordpress.com/rest/v1.1/sites/15592836/post/0/diffs/?locale=it_IT
    com.android.volley.ServerError
        at com.android.volley.toolbox.BasicNetwork.performRequest(BasicNetwork.java:179)
        at com.android.volley.NetworkDispatcher.run(NetworkDispatcher.java:114)
2019-05-16 10:44:35.093 2451-2451/org.wordpress.android D/WordPress-API: Dispatching action: PostAction-FETCHED_REVISIONS
2019-05-16 10:44:35.096 2451-2451/org.wordpress.android E/WordPress-API: An error occurred while fetching History revisions

Tested on develop -12be9e050f2be8199de8ec04a3672a74e3984d1e

Start by tracing the new-post flow that triggers the History revisions request and inspect how the post ID is passed to the WordPress API endpoint /sites/15592836/post/0/diffs/. Reproduce the issue on develop commit 12be9e050f2be8199de8ec04a3672a74e3984d1e; done means a locally created post no longer requests revisions with ID 0 while existing-post revision loading remains available.