From 4462ecfdacd19087b6a8e01ddfdd2d9aec4cea3b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=87a=C4=9Fan=20=C3=96zcan?=
 <232228291+yorgunkral31@users.noreply.github.com>
Date: Mon, 21 Sep 2026 15:36:25 +0300
Subject: [PATCH] fix: skip draws whose render pipeline failed to compile

Encoding a draw with a null MTLRenderPipelineState is undefined
behavior; when newRenderPipelineState fails (for example on a vertex
attribute/shader type mismatch that only some OS versions reject), the
failed pipeline's draws now get skipped instead of encoding garbage,
and the state cache no longer binds a null pipeline.
---
 plume_metal.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/plume_metal.cpp b/plume_metal.cpp
index b670ed3..246edb6 100644
--- a/plume_metal.cpp
+++ b/plume_metal.cpp
@@ -2491,6 +2491,10 @@ namespace plume {
     void MetalCommandList::drawInstanced(const uint32_t vertexCountPerInstance, const uint32_t instanceCount, const uint32_t startVertexLocation, const uint32_t startInstanceLocation) {
         assert(activeGraphicsPipelineLayout != nullptr);
 
+        // Skip draws whose pipeline failed to compile; encoding with a null PSO is undefined behavior.
+        if (activeRenderState == nullptr || activeRenderState->renderPipelineState == nullptr)
+            return;
+
         MetalAutoreleasePool releasePool;
         checkActiveRenderEncoder();
         checkForUpdatesInGraphicsState();
@@ -2501,6 +2505,10 @@ namespace plume {
     void MetalCommandList::drawIndexedInstanced(const uint32_t indexCountPerInstance, const uint32_t instanceCount, const uint32_t startIndexLocation, const int32_t baseVertexLocation, const uint32_t startInstanceLocation) {
         assert(activeGraphicsPipelineLayout != nullptr);
 
+        // Skip draws whose pipeline failed to compile; encoding with a null PSO is undefined behavior.
+        if (activeRenderState == nullptr || activeRenderState->renderPipelineState == nullptr)
+            return;
+
         MetalAutoreleasePool releasePool;
         checkActiveRenderEncoder();
         checkForUpdatesInGraphicsState();
@@ -3395,7 +3403,7 @@ namespace plume {
     void MetalCommandList::checkForUpdatesInGraphicsState() {
         // Pipeline state - only update if the actual pipeline object changed
         if (dirtyGraphicsState.pipelineState) {
-            if (activeRenderState && activeRenderState->renderPipelineState != stateCache.lastPipelineState) {
+            if (activeRenderState && activeRenderState->renderPipelineState != nullptr && activeRenderState->renderPipelineState != stateCache.lastPipelineState) {
                 activeRenderEncoder->setRenderPipelineState(activeRenderState->renderPipelineState);
                 stateCache.lastPipelineState = activeRenderState->renderPipelineState;
             }