  Research on automatic software repair is concerned with the development of
systems that automatically detect and repair bugs. One well-known class of bugs
is the infinite loop. Every computer programmer or user has, at least once,
experienced this type of bug. We state the problem of repairing infinite loops
in the context of test-suite based software repair: given a test suite with at
least one failing test, generate a patch that makes all test cases pass.
Consequently, repairing infinites loop means having at least one test case that
hangs by triggering the infinite loop. Our system to automatically repair
infinite loops is called $Infinitel$. We develop a technique to manipulate
loops so that one can dynamically analyze the number of iterations of loops;
decide to interrupt the loop execution; and dynamically examine the state of
the loop on a per-iteration basis. Then, in order to synthesize a new loop
condition, we encode this set of program states as a code synthesis problem
using a technique based on Satisfiability Modulo Theory (SMT). We evaluate our
technique on seven seeded-bugs and on seven real-bugs. $Infinitel$ is able to
repair all of them, within seconds up to one hour on a standard laptop
configuration.
