restore the interrupt flag whenever we catch InterruptedException (#801)

Co-authored-by: Alex Heneveld <alex@cloudsoft.io>

src/main/java/net/schmizz/concurrent/Promise.java

@@ -176,6 +176,7 @@ public V tryRetrieve(long timeout, TimeUnit unit)
             }
             return val;
         } catch (InterruptedException ie) {
+            Thread.currentThread().interrupt();
             throw chainer.chain(ie);
         } finally {
             lock.unlock();

src/main/java/net/schmizz/keepalive/KeepAlive.java

@@ -75,6 +75,8 @@ public void run() {
                 TimeUnit.SECONDS.sleep(interval);
             }
         } catch (InterruptedException e) {
+            // this is almost certainly a planned interruption, but even so, no harm in setting the interrupt flag
+            Thread.currentThread().interrupt();
             log.trace("{} Interrupted while sleeping", getClass().getSimpleName());
         } catch (Exception e) {
             // If we weren't interrupted, kill the transport, then this exception was unexpected.

src/main/java/net/schmizz/sshj/connection/channel/ChannelInputStream.java

@@ -105,6 +105,7 @@ public int read(byte[] b, int off, int len)
                 try {
                     buf.wait();
                 } catch (InterruptedException e) {
+                    Thread.currentThread().interrupt();
                     throw (IOException) new InterruptedIOException().initCause(e);
                 }
             }

src/main/java/net/schmizz/sshj/connection/channel/Window.java

@@ -93,6 +93,7 @@ public long awaitExpansion(long was) throws ConnectionException {
                             throw new ConnectionException("Timeout when trying to expand the window size");
                         }
                     } catch (InterruptedException ie) {
+                        Thread.currentThread().interrupt();
                         throw new ConnectionException(ie);
                     }
                 }