Add safety check to getNextTimeout()

It currently won't ever be called with an empty list of timers, but it
is a public function so that might happen in the future. Make sure this
case is handled without crashes.

1 files changed, 6 insertions, 0 deletions

diff --git a/common/rfb/Timer.cxx b/common/rfb/Timer.cxx
index d1a6373b..dc17606e 100644
--- a/common/rfb/Timer.cxx
+++ b/common/rfb/Timer.cxx
@@ -104,7 +104,12 @@ int Timer::checkTimeouts() {
 int Timer::getNextTimeout() {
   timeval now;
   gettimeofday(&now, 0);
+
+  if (pending.empty())
+    return -1;
+
   int toWait = pending.front()->getRemainingMs();
+
   if (toWait > pending.front()->timeoutMs) {
     if (toWait - pending.front()->timeoutMs < 1000) {
       vlog.info("gettimeofday is broken...");
@@ -115,6 +120,7 @@ int Timer::getNextTimeout() {
     pending.front()->dueTime = now;
     toWait = 0;
   }
+
   return toWait;
 }