__compact_file can perform hundreds of unnecessary checkpoints

/*

 * We compact 10% of the file on each pass (but the overall size of the

 * file is decreasing each time, so we're not compacting 10% of the

 * original file each time). Try 100 times (which is clearly more than

 * we need); quit if we make no progress and check for a timeout each

 * time through the loop.

 */

for (i = 0; i < 100; ++i) {

    WT_ERR(wt_session->checkpoint(wt_session, t->data));

    session->compaction = 0;

    WT_WITH_SCHEMA_LOCK(session,

        ret = __wt_schema_worker(

        session, uri, __wt_compact, NULL, cfg, 0));

    WT_ERR(ret);

    if (!session->compaction)

        break;

    WT_ERR(wt_session->checkpoint(wt_session, t->data));

    WT_ERR(wt_session->checkpoint(wt_session, t->data));

    WT_ERR(__session_compact_check_timeout(session, start_time));

}

'use strict';

var t = db.compact;

t.drop();

t.insert({});

for (var i = 0; i < 100; i++) {

    var res = db.runCommand({compact: t.getName()});

    assert.commandWorked(res);

}