qt: clamp timer interval to INT_MAX ms (#4305)

platform/qt/src/mbgl/timer.cpp

@@ -3,11 +3,30 @@
 #include <mbgl/util/run_loop.hpp>
 #include <mbgl/util/timer.hpp>
 
+#include <algorithm>
+#include <limits>
 #include <memory>
 
 namespace mbgl {
 namespace util {
 
+namespace {
+// QTimer stores its millisecond interval in an int, so any value above
+// INT_MAX (~24.85 days) is clamped by Qt and produces a runtime warning:
+//   "QTimer::start: interval exceeds maximum allowed interval, it will be
+//    clamped to INT_MAX ms (about 24 days)."
+// MapLibre core can legitimately schedule timers far in the future, e.g.
+// when a tile arrives with a long-lived `Cache-Control: max-age=31536000`
+// (one year) header and the cache expiry timer is armed from it. Cap the
+// value here so Qt stays silent; anything beyond INT_MAX ms is effectively
+// "never fires" for any practical map session anyway.
+constexpr uint64_t kMaxIntervalMs = static_cast<uint64_t>(std::numeric_limits<int>::max());
+
+std::chrono::milliseconds clampInterval(uint64_t value) {
+    return std::chrono::milliseconds(std::min(value, kMaxIntervalMs));
+}
+} // namespace
+
 Timer::Impl::Impl() {
     timer.setTimerType(Qt::PreciseTimer);
     connect(&timer, &QTimer::timeout, this, &Timer::Impl::timerFired);
@@ -18,7 +37,7 @@ void Timer::Impl::start(uint64_t timeout, uint64_t repeat_, std::function<void()
     callback = std::move(cb);
 
     timer.setSingleShot(true);
-    timer.start(static_cast<std::chrono::milliseconds>(timeout));
+    timer.start(clampInterval(timeout));
 }
 
 void Timer::Impl::stop() {
@@ -28,7 +47,7 @@ void Timer::Impl::stop() {
 void Timer::Impl::timerFired() {
     if (repeat) {
         timer.setSingleShot(false);
-        timer.start(static_cast<std::chrono::milliseconds>(repeat));
+        timer.start(clampInterval(repeat));
     }
 
     callback();