// If an index is added while an update operation is yielding, the updated documents should be
// indexed correctly.

t = db.jstests_updatel;
t.drop();

// Insert some { a:0 } values.
for( i = 0; i < 50000; ++i ) {
    t.save( { a:0 } );
}
db.getLastError();

p = startParallelShell(
                       // Wait until the update operation (below) begins running.
                       'while( db.jstests_updatel.find( { a:1 } ).limit( -1 ).itcount() == 0 );' +
                       // Add an index on { a:1 }.
                       'db.jstests_updatel.ensureIndex( { a:1 } );'
                       );

// Update all documents to { a:1 }.
t.update( {}, { $set: { a:1 } }, false, true );

p();

// Check that the { a:1 } index contains all { a:1 } values.
assert.eq( 50000, t.find( { a:1 } ).hint( { a:1 } ).itcount() );