From: Pierre Ossman <ossman@cendio.se>
Date: Tue, 3 Jan 2023 08:27:46 +0000 (+0100)
Subject: Add safety check to getNextTimeout()
X-Git-Tag: v1.13.90~5^2~10
X-Git-Url: https://source.dussan.org/?a=commitdiff_plain;h=265c50f5af024d20191eb9d37ee21112593e3aa1;p=tigervnc.git

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.
---

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;
 }