Fix: Crash when realtime compositor node is unlinked

The realtime compositor crashes when some nodes are unlinked.

This happens for GPU material nodes if it was compiled into its own
shader operation. Since it is unlinked, the shader operation will have
no inputs, a case that the current code didn't consider.

This patch fixes this by skipping code generation for inputs if no
inputs exist for the shader operation.

1 files changed, 4 insertions, 0 deletions

diff --git a/source/blender/compositor/realtime_compositor/intern/shader_operation.cc b/source/blender/compositor/realtime_compositor/intern/shader_operation.cc
index a097c81a4c5..5749d8c5f2e 100644
--- a/source/blender/compositor/realtime_compositor/intern/shader_operation.cc
+++ b/source/blender/compositor/realtime_compositor/intern/shader_operation.cc
@@ -481,6 +481,10 @@ void ShaderOperation::generate_code_for_inputs(GPUMaterial *material,
   /* The attributes of the GPU material represents the inputs of the operation. */
   ListBase attributes = GPU_material_attributes(material);
 
+  if (BLI_listbase_is_empty(&attributes)) {
+    return;
+  }
+
   /* Add a texture sampler for each of the inputs with the same name as the attribute. */
   LISTBASE_FOREACH (GPUMaterialAttribute *, attribute, &attributes) {
     shader_create_info.sampler(0, ImageType::FLOAT_2D, attribute->name, Frequency::BATCH);