Run the imgui processing early in the frame, only do the rendering late

UI/EmuScreen.cpp

@@ -1539,6 +1539,11 @@ ScreenRenderFlags EmuScreen::render(ScreenRenderMode mode) {
 		}
 	}
 
+	// Running it early allows things like direct readbacks of buffers, things we can't do
+	// when we have started the final render pass. Well, technically we probably could with some manipulation
+	// of pass order in the render managers..
+	runImDebugger();
+
 	bool blockedExecution = Achievements::IsBlockingExecution();
 	uint32_t clearColor = 0;
 	if (!blockedExecution) {
@@ -1655,7 +1660,7 @@ ScreenRenderFlags EmuScreen::render(ScreenRenderMode mode) {
 	return flags;
 }
 
-void EmuScreen::renderImDebugger() {
+void EmuScreen::runImDebugger() {
 	if (g_Config.bShowImDebugger) {
 		Draw::DrawContext *draw = screenManager()->getDrawContext();
 		if (!imguiInited_) {
@@ -1691,6 +1696,14 @@ void EmuScreen::renderImDebugger() {
 			imDebugger_->Frame(currentDebugMIPS, gpuDebug);
 
 			ImGui::Render();
+		}
+	}
+}
+
+void EmuScreen::renderImDebugger() {
+	if (g_Config.bShowImDebugger) {
+		Draw::DrawContext *draw = screenManager()->getDrawContext();
+		if (PSP_IsInited()) {
 			ImGui_ImplThin3d_RenderDrawData(ImGui::GetDrawData(), draw);
 		}
 	}

UI/EmuScreen.h

@@ -79,6 +79,7 @@ private:
 	void bootComplete();
 	bool hasVisibleUI();
 	void renderUI();
+	void runImDebugger();
 	void renderImDebugger();
 
 	void onVKey(int virtualKeyCode, bool down);

UI/ImDebugger/ImDebugger.cpp

@@ -65,6 +65,9 @@ void ShowInWindowMenuItems(uint32_t addr, ImControl &control) {
 }
 
 void StatusBar(std::string_view status) {
+	if (!status.size()) {
+		return;
+	}
 	ImGui::TextUnformatted(status.data(), status.data() + status.length());
 	ImGui::SameLine();
 	if (ImGui::SmallButton("Copy")) {