RHI renderer: fix crash when executing a draw RV after a compute RV

RHI resource update batches are released when we pass them to
beginPass() or endPass(). We must then either clear the m_currentUpdates
pointer, or assign it to a new batch.

The later was done after all endPass(). But we forgot to clear the
m_currentUpdates pointer after beginPass(), which resulted in a crash,
since we then sent the same -released- batch pointer to the following
endPass().

This crash did not manifest before
6b6465032f103a084e416cbddf03f8e83191aea2 because then all batches were
leaked (never released).

Fixes: QTBUG-119657
Change-Id: Ic63a96fc58714099b0a4e65e495ae0a720a3823f
Reviewed-by: Mike Krus <mike.krus@kdab.com>
(cherry picked from commit 708b851eb5afcb5ae4019777b56787cce4910c8b)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 9 insertions, 1 deletions

diff --git a/src/plugins/renderers/rhi/renderer/renderer.cpp b/src/plugins/renderers/rhi/renderer/renderer.cpp
index c3fb610f5..824e741a5 100644
--- a/src/plugins/renderers/rhi/renderer/renderer.cpp
+++ b/src/plugins/renderers/rhi/renderer/renderer.cpp
@@ -2759,6 +2759,7 @@ bool Renderer::executeCommandsSubmission(const RHIPassInfo &passInfo)
             if (supportsCompute) {
                 if (!inCompute) {
                     cb->beginComputePass(m_submissionContext->m_currentUpdates);
+                    m_submissionContext->m_currentUpdates = nullptr;
                     inCompute = true;
                 }
                 executeComputeRenderView(rv);
@@ -2780,6 +2781,7 @@ bool Renderer::executeCommandsSubmission(const RHIPassInfo &passInfo)
                     continue;
                 }
                 cb->beginPass(rhiRenderTarget, clearColor, clearDepthStencil, m_submissionContext->m_currentUpdates);
+                m_submissionContext->m_currentUpdates = nullptr;
                 inDraw = true;
             }
 
@@ -2845,7 +2847,13 @@ bool Renderer::executeCommandsSubmission(const RHIPassInfo &passInfo)
     else if (inCompute)
         cb->endComputePass();
 
-    m_submissionContext->m_currentUpdates = m_submissionContext->rhi()->nextResourceUpdateBatch();
+    if (!renderViews.empty()) {
+        Q_ASSERT(m_submissionContext->m_currentUpdates == nullptr); // ensures that we are not leaking a batch
+        m_submissionContext->m_currentUpdates = m_submissionContext->rhi()->nextResourceUpdateBatch();
+    }
+    else {
+        // Keep the m_submissionContext->m_currentUpdates
+    }
 
     return allCommandsIssued;
 }