text: // Test index key generation with duplicate values addressed by array index and
  // object field.  SERVER-2902
  
  t = db.jstests_indexu;
  t.drop();
  
  var dupDoc = {a:[{'0':1}]}; // There are two 'a.0' fields in this doc.
  var dupDoc2 = {a:[{'1':1},'c']};
  var noDupDoc = {a:[{'1':1}]};
  
  // Test that we can't index dupDoc.
  t.save( dupDoc );
  assert( !db.getLastError() );
  t.ensureIndex( {'a.0':1} );
  assert( db.getLastError() );
  
  t.remove();
  t.ensureIndex( {'a.0':1} );
  assert( !db.getLastError() );
  t.save( dupDoc );
  assert( db.getLastError() );
  
  // Test that we can't index dupDoc2.
  t.drop();
  t.save( dupDoc2 );
  assert( !db.getLastError() );
  t.ensureIndex( {'a.1':1} );
  assert( db.getLastError() );
  
  t.remove();
  t.ensureIndex( {'a.1':1} );
  assert( !db.getLastError() );
  t.save( dupDoc2 );
  assert( db.getLastError() );
  
  // Test that we can index dupDoc with a different index.
  t.drop();
  t.ensureIndex( {'a.b':1} );
  t.save( dupDoc );
  assert( !db.getLastError() );
  
  // Test number field starting with hyphen.
  t.drop();
  t.ensureIndex( {'a.-1':1} );
  t.save( {a:[{'-1':1}]} );
  assert( !db.getLastError() );
  
  // Test number field starting with zero.
  t.drop();
  t.ensureIndex( {'a.00':1} );
  t.save( {a:[{'00':1}]} );
  assert( !db.getLastError() );
  
  // Test multiple array indexes
  t.drop();
  t.ensureIndex( {'a.0':1,'a.1':1} );
  t.save( {a:[{'1':1}]} );
  assert( !db.getLastError() );
  t.save( {a:[{'1':1},4]} );
  assert( db.getLastError() );
  
  // Test that we can index noDupDoc.
  t.drop();
  t.save( noDupDoc );
  t.ensureIndex( {'a.0':1} );
  assert( !db.getLastError() );
  t.ensureIndex( {'a.1':1} );
  assert( !db.getLastError() );
  
  t.drop();
  t.ensureIndex( {'a.0':1} );
  t.ensureIndex( {'a.1':1} );
  t.save( noDupDoc );
  assert( !db.getLastError() );
  
  // Test that we can query noDupDoc.
  assert.eq( 1, t.find( {'a.1':1} ).hint( {'a.1':1} ).itcount() );
  assert.eq( 1, t.find( {'a.1':1} ).hint( {$natural:1} ).itcount() );
  assert.eq( 1, t.find( {'a.0':{'1':1}} ).hint( {'a.0':1} ).itcount() );
  assert.eq( 1, t.find( {'a.0':{'1':1}} ).hint( {$natural:1} ).itcount() );
  
  // Check multiple nested array fields.
  t.drop();
  t.save( {a:[[1]]} );
  t.ensureIndex( {'a.0.0':1} );
  assert( !db.getLastError() );
  assert.eq( 1, t.find( {'a.0.0':1} ).hint( {$natural:1} ).itcount() );
  assert.eq( 1, t.find( {'a.0.0':1} ).hint( {'a.0.0':1} ).itcount() );
  
  // Check where there is a duplicate for a partially addressed field but not for a fully addressed field.
  t.drop();
  t.save( {a:[[1],{'0':1}]} );
  t.ensureIndex( {'a.0.0':1} );
  assert( db.getLastError() );
  
  // Check where there is a duplicate for a fully addressed field.
  t.drop();
  t.save( {a:[[1],{'0':[1]}]} );
  assert( !db.getLastError() );
  t.ensureIndex( {'a.0.0':1} );
  assert( db.getLastError() );
  
  // Two ways of addressing parse to an array.
  t.drop();
  t.save( {a:[{'0':1}]} );
  t.ensureIndex( {'a.0.0':1} );
  assert( db.getLastError() );
  
  // Test several key depths - with same arrays being found.
  t.drop();
  t.save( {a:[{'0':[{'0':1}]}]} );
  t.ensureIndex( {'a.0.0.0.0.0.0':1} );
  assert( db.getLastError() );
  t.ensureIndex( {'a.0.0.0.0.0':1} );
  assert( db.getLastError() );
  t.ensureIndex( {'a.0.0.0.0':1} );
  assert( db.getLastError() );
  t.ensureIndex( {'a.0.0.0':1} );
  assert( db.getLastError() );
  t.ensureIndex( {'a.0.0':1} );
  assert( db.getLastError() );
  t.ensureIndex( {'a.0':1} );
  assert( db.getLastError() );
  t.ensureIndex( {'a':1} );
  assert( !db.getLastError() );
  
  // Two prefixes extract docs, but one terminates extraction before array.
  t.drop();
  t.save( {a:[{'0':{'c':[]}}]} );
  t.ensureIndex( {'a.0.c':1} );
  assert( db.getLastError() );
  
  t.drop();
  t.save( {a:[[{'b':1}]]} );
  assert.eq( 1, t.find( {'a.0.b':1} ).itcount() );
  t.ensureIndex( {'a.0.b':1} );
  assert.eq( 1, t.find( {'a.0.b':1} ).itcount() );
  