Inconsistent behavior when querying design documents with null, empty and invalid data

[lasselaakkonen]

When POSTing queries to a design document through the REST API:

When POSTing an empty request body

• macOS CBL 1.4.0 returns HTTP 400 with body {"status":400,"error":"Invalid parameter in HTTP query or JSON body"}
• Android CBL 1.4.0 returns HTTP 493 with body {"error":"Invalid JSON","status":400,"reason":"Router unable to route request to do_POST_DesignDocumentcom.couchbase.lite.CouchbaseLiteException, Status: 493 (HTTP 400 Invalid JSON)"}
• Didn't test other platforms

When POSTing {} as body

• macOS CBL 1.4.0 returns HTTP 400 with body {"status":400,"error":"Invalid parameter in HTTP query or JSON body"}
• Android CBL 1.4.0 returns HTTP 200 with all documents
• Didn't test other platforms

When POSTing { foo: 123 } as body

• macOS CBL 1.4.0 returns HTTP 400 with body {"status":400,"error":"Invalid parameter in HTTP query or JSON body"}
• Android CBL 1.4.0 returns HTTP 200 with all documents
• Didn't test other platforms

When POSTing { keys: [] } as body

• macOS CBL 1.4.0 returns HTTP 200 with no documents
• Android CBL 1.4.0 returns HTTP 200 with all documents
• Didn't test other platforms

I ran in to the issue when POSTing {} as body, because of how my code happened to be structured. What I wanted was to get all documents, so I switched to using GET without parameters.

All platforms should work the same way, to avoid having to debug/test issues separately on all platforms.