a search index upon a field which contains numerical strings fails on querying unless an alpha character is included

[bpluly]

Description

A document contains a user account object which contains user ids for various platforms that of which they are also a user.
This is a simple array of a two field structure.
eg.

 "_id": xxxxx",
  "_rev": "2-xxx",
  "userAccount": {
    "platforms": [
      {
        "platform": "twitter",
        "userPlatformID": "15078174"
      }
    ],

The system needs to be able to lookup the userPlatformID because it wants to associate the user with whatever. The field is a string because an unknown Platform will have whatever ID format it likes, in this case it is a numerical string. However after creating the Search_index no numerical string queried returns any hits.

Given the above document create a Search Index to navigate the documents and safely create an index for the two platforms fields.

function (doc) {
  index('default', doc._id);
  if (typeof(doc.userAccount) !== 'undefined' ){
    for (platformInd = 0; platformInd < doc.userAccount.platforms.length; platformInd++){
      if (typeof(doc.userAccount.platforms[platformInd].userPlatformID) !== 'undefined'){
        index('platformid', doc.userAccount.platforms[platformInd].userPlatformID, {'index':true, 'store':true}); 
        }
        index('platform', doc.userAccount.platforms[platformInd].platform, {'index':true});
    }
  }
}  

The index builds and any query for 'platform:' will return any hits but no hits for any 'platformid'. Storing the platformid shows in platform: query results that the value is stored as a string.

After some little time I prefixed the platformid field in the indexing with a 'P' and that returns results.

Couchdb 3.1.0
on AWS Linux 2 patched and up to date.

Only tested with Firefox but it's not a client issue, only Fauxton was used to reproduce this.