Fix T101651: Cycles crashes when failing to initialize render device

The issue here was that PathTraceWork was set up before checking if
any error occurred, and it didn't account for the dummy device so
it called a non-implemented function.

This fix therefore avoids creating PathTraceWork for dummy devices
and checks for device creation errors earlier in the process.

4 files changed, 16 insertions, 2 deletions

diff --git a/intern/cycles/integrator/path_trace.cpp b/intern/cycles/integrator/path_trace.cpp
index 3ec7b601d9f..ae03ee0b9a5 100644
--- a/intern/cycles/integrator/path_trace.cpp
+++ b/intern/cycles/integrator/path_trace.cpp
@@ -43,8 +43,11 @@ PathTrace::PathTrace(Device *device,
   /* Create path tracing work in advance, so that it can be reused by incremental sampling as much
    * as possible. */
   device_->foreach_device([&](Device *path_trace_device) {
-    path_trace_works_.emplace_back(PathTraceWork::create(
-        path_trace_device, film, device_scene, &render_cancel_.is_requested));
+    unique_ptr<PathTraceWork> work = PathTraceWork::create(
+        path_trace_device, film, device_scene, &render_cancel_.is_requested);
+    if (work) {
+      path_trace_works_.emplace_back(std::move(work));
+    }
   });
 
   work_balance_infos_.resize(path_trace_works_.size());
diff --git a/intern/cycles/integrator/path_trace_work.cpp b/intern/cycles/integrator/path_trace_work.cpp
index bb5c6e1a61a..a5f98b5475a 100644
--- a/intern/cycles/integrator/path_trace_work.cpp
+++ b/intern/cycles/integrator/path_trace_work.cpp
@@ -23,6 +23,10 @@ unique_ptr<PathTraceWork> PathTraceWork::create(Device *device,
   if (device->info.type == DEVICE_CPU) {
     return make_unique<PathTraceWorkCPU>(device, film, device_scene, cancel_requested_flag);
   }
+  if (device->info.type == DEVICE_DUMMY) {
+    /* Dummy devices can't perform any work. */
+    return nullptr;
+  }
 
   return make_unique<PathTraceWorkGPU>(device, film, device_scene, cancel_requested_flag);
 }
diff --git a/intern/cycles/integrator/work_balancer.cpp b/intern/cycles/integrator/work_balancer.cpp
index 5f1c6c92b9d..0fe170b2791 100644
--- a/intern/cycles/integrator/work_balancer.cpp
+++ b/intern/cycles/integrator/work_balancer.cpp
@@ -17,6 +17,9 @@ void work_balance_do_initial(vector<WorkBalanceInfo> &work_balance_infos)
     work_balance_infos[0].weight = 1.0;
     return;
   }
+  else if (num_infos == 0) {
+    return;
+  }
 
   /* There is no statistics available, so start with an equal distribution. */
   const double weight = 1.0 / num_infos;
diff --git a/intern/cycles/session/session.cpp b/intern/cycles/session/session.cpp
index de685a47003..15bb93b0385 100644
--- a/intern/cycles/session/session.cpp
+++ b/intern/cycles/session/session.cpp
@@ -43,6 +43,10 @@ Session::Session(const SessionParams &params_, const SceneParams &scene_params)
 
   device = Device::create(params.device, stats, profiler);
 
+  if (device->have_error()) {
+    progress.set_error(device->error_message());
+  }
+
   scene = new Scene(scene_params, device);
 
   /* Configure path tracer. */