Get the result from the connection after the green panic

Otherwise the connection won't be usable in case we manage
to put it back on track (libpq reports "another command is
already in progress")

psycopg/green.c

@@ -202,6 +202,7 @@ end:
 static void
 psyco_panic_cancel(connectionObject *conn)
 {
+    PGresult *res;
     PyObject *etype, *evalue, *etb;
     char errbuf[256];
 
@@ -229,6 +230,12 @@ psyco_panic_cancel(connectionObject *conn)
         goto exit;
     }
 
+    /* we must clear the result or we get "another command is already in
+     * progress" */
+    if (NULL != (res = pq_get_last_result(conn))) {
+        PQclear(res);
+    }
+
 exit:
     /* restore the exception. If no exception was set at function begin, don't
      * clobber one that may have been set here. */

sandbox/test_green_error.py

@@ -42,7 +42,15 @@ signal.signal(signal.SIGHUP, handler)
 conn = psycopg2.connect(DSN)
 curs = conn.cursor()
 print "PID", os.getpid()
-curs.execute("select pg_sleep(1000)")
+try:
+    curs.execute("select pg_sleep(1000)")
+except BaseException, e:
+    print "got exception:", e.__class__.__name__, e
+
+conn.rollback()
+curs.execute("select 1")
+print curs.fetchone()
+
 
 # You can unplug the network cable etc. here.
 # Kill -HUP will raise an exception in the callback.