Fix blur capture robustness and null derefs

Co-authored-by: dy-tea <165158232+dy-tea@users.noreply.github.com>

Author: Copilot

src/effects.c

@@ -751,6 +751,8 @@ static bool rebuild_live_blur(output_t *output, uint64_t shared_blurred, pixman_
 	effects_output_t *ctx = output->effects;
 	int w = output->width, h = output->height;
 	bool any = false;
+	bool blur_buf_reusable = ctx->blur_buf && ctx->blur_native[0] && ctx->blur_buf_w == ctx->blur_w &&
+		ctx->blur_buf_h == ctx->blur_h;
 
 	struct be_blur_params bp = {
 		.algorithm = blur_algorithm,
@@ -814,9 +816,12 @@ static bool rebuild_live_blur(output_t *output, uint64_t shared_blurred, pixman_
 		}
 
 		int n_scissor = 0;
-		const pixman_box32_t *scissor = blur_damage_boxes(ctx, damage, w, h, &n_scissor);
-		effects_backend->blur(&ctx->be_state, shared_blurred, ctx->blur_w, ctx->blur_h, &bp,
-			ctx->blur_native[0], scissor, n_scissor, NULL);
+		const pixman_box32_t *scissor = NULL;
+		if (blur_buf_reusable)
+			scissor = blur_damage_boxes(ctx, damage, w, h, &n_scissor);
+		if (!effects_backend->blur(&ctx->be_state, shared_blurred, ctx->blur_w, ctx->blur_h, &bp,
+				ctx->blur_native[0], scissor, n_scissor, NULL))
+			return false;
 		ctx->blur_gen = ctx->backdrop_gen;
 	}
 	any = true;
@@ -1061,6 +1066,8 @@ static void push_blur_to_toplevels(output_t *output) {
 static bool rebuild_live_blur_layers(output_t *output, uint64_t bg_tex, pixman_region32_t *damage) {
 	effects_output_t *ctx = output->effects;
 	int w = output->width, h = output->height;
+	bool layer_blur_buf_reusable = ctx->layer_blur_buf && ctx->layer_blur_native[0] &&
+		ctx->layer_blur_buf_w == ctx->blur_w && ctx->layer_blur_buf_h == ctx->blur_h;
 
 	struct be_blur_params bp = {
 		.algorithm = blur_algorithm,
@@ -1090,9 +1097,12 @@ static bool rebuild_live_blur_layers(output_t *output, uint64_t bg_tex, pixman_r
 		return false;
 
 	int n_scissor = 0;
-	const pixman_box32_t *scissor = blur_damage_boxes(ctx, damage, w, h, &n_scissor);
-	effects_backend->blur(&ctx->be_state, bg_tex, ctx->blur_w, ctx->blur_h, &bp,
-		ctx->layer_blur_native[0], scissor, n_scissor, NULL);
+	const pixman_box32_t *scissor = NULL;
+	if (layer_blur_buf_reusable)
+		scissor = blur_damage_boxes(ctx, damage, w, h, &n_scissor);
+	if (!effects_backend->blur(&ctx->be_state, bg_tex, ctx->blur_w, ctx->blur_h, &bp,
+			ctx->layer_blur_native[0], scissor, n_scissor, NULL))
+		return false;
 	ctx->layer_blur_gen = ctx->backdrop_gen;
 	return true;
 }
@@ -1735,7 +1745,7 @@ static bool rebuild_corner_masks(output_t *output, uint64_t bg_tex) {
 		if (content_r.width <= 0 || content_r.height <= 0)
 			continue;
 
-		uint64_t src;
+		uint64_t src = 0;
 		if (bg_tex) {
 			src = bg_tex;
 		} else {
@@ -1775,10 +1785,12 @@ static bool rebuild_corner_masks(output_t *output, uint64_t bg_tex) {
 					if (bnode)
 						HIDE_IF(&bnode->node);
 				}
-				HIDE_IF(&tl->blur->mica_node->node);
-				HIDE_IF(&tl->blur->acrylic_node->node);
+				if (tl->blur->mica_node)
+					HIDE_IF(&tl->blur->mica_node->node);
+				if (tl->blur->acrylic_node)
+					HIDE_IF(&tl->blur->acrylic_node->node);
 			}
-			if (tl->rounded)
+			if (tl->rounded && tl->rounded->corner_mask_node)
 				HIDE_IF(&tl->rounded->corner_mask_node->node);
 
 			wlr_damage_ring_add_whole(&ctx->capture_scene_output->damage_ring);
@@ -1937,12 +1949,13 @@ static uint64_t capture_full_scene_to_tex(output_t *output, effects_output_t *ct
 	wlr_scene_output_set_position(ctx->capture_scene_output, -0x7fff, -0x7fff);
 
 	if (!ok || !ctx->capture_state.buffer) {
-		wlr_buffer_unlock(ctx->capture_state.buffer);
+		if (ctx->capture_state.buffer)
+			wlr_buffer_unlock(ctx->capture_state.buffer);
 		ctx->capture_state.buffer = NULL;
 		return 0;
 	}
 
-	uint64_t result;
+	uint64_t result = 0;
 	effects_backend->capture_readback(ctx->capture_state.buffer, &ctx->be_state, screen_fbo, 0, 0, w, h,
 		0, 0, w, h, &result);
 

src/effects_gles2.c

@@ -791,7 +791,8 @@ static bool gles2_blur(be_output_state_t *state, uint64_t src_handle, int src_w,
 			if (out_handle)
 				*out_handle = 0;
 		} else {
-			*out_handle = src_handle;
+			if (out_handle)
+				*out_handle = src_handle;
 		}
 		return true;
 	}

src/effects_vk.c

@@ -840,7 +840,7 @@ static bool vk_init(struct wlr_renderer *r, struct wlr_allocator *a) {
 	for (int i = 0; i < 4; i++) {
 		VkAttachmentLoadOp loadOp = (VkAttachmentLoadOp[]){
 			VK_ATTACHMENT_LOAD_OP_CLEAR,
-			VK_ATTACHMENT_LOAD_OP_DONT_CARE,
+			VK_ATTACHMENT_LOAD_OP_LOAD,
 			VK_ATTACHMENT_LOAD_OP_CLEAR,
 			VK_ATTACHMENT_LOAD_OP_LOAD,
 		} [i];
@@ -1756,7 +1756,8 @@ static bool vk_blur(be_output_state_t *state, uint64_t src_handle, int src_w, in
 			if (out_handle)
 				*out_handle = 0;
 		} else {
-			*out_handle = src_handle;
+			if (out_handle)
+				*out_handle = src_handle;
 		}
 		return true;
 	}