Take the 2-minute tour ×  I am asking this question anonymously
and apologize for the paranoia.  Suppose you submit a paper on a
topic and, while the paper is under review, continue to work on
the topic and make enough progress to prepare a second paper. I
know that submitting the second paper while the first is still
under review is typical, but what do you do if the first paper
is rejected around the time the second is submitted? Similarly,
what if the second paper is accepted and then the first paper is
rejected? Do you resubmit the first?  Note that the second paper
doesn’t simply duplicate the results of the first in a more
general setting; it relies on the results of the first and uses
different techniques to extend them.  I know there are cases
where the right thing to do (if the timing makes it possible) is
to combine the papers into one. But suppose this would be
inappropriate, because the combined paper would be too long or
too cluttered with different ideas.  So, specifically:  1. If
the first pape