[PATCH weston] drm: don't put too big surfaces in the cursor plane

[Giulio Camuffo]

When using output scaling a client surface's wicth and height can be
smaller than the cursor plane's size, even if its buffer is actually
bigger. So check the buffer size rather than the surface size.
---
 libweston/compositor-drm.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c
index a899213..0913f6c 100644
--- a/libweston/compositor-drm.c
+++ b/libweston/compositor-drm.c
@@ -1127,6 +1127,7 @@ drm_output_prepare_cursor_view(struct drm_output *output,
 	struct drm_backend *b = to_drm_backend(output->base.compositor);
 	struct weston_buffer_viewport *viewport = &ev->surface->buffer_viewport;
 	struct wl_shm_buffer *shmbuf;
+	struct weston_buffer *buffer = ev->surface->buffer_ref.buffer;
 
 	if (ev->transform.enabled &&
 	    (ev->transform.matrix.type > WESTON_MATRIX_TRANSFORM_TRANSLATE))
@@ -1147,13 +1148,13 @@ drm_output_prepare_cursor_view(struct drm_output *output,
 		return NULL;
 	if (ev->surface->buffer_ref.buffer == NULL)
 		return NULL;
-	shmbuf = wl_shm_buffer_get(ev->surface->buffer_ref.buffer->resource);
+	shmbuf = wl_shm_buffer_get(buffer->resource);
 	if (!shmbuf)
 		return NULL;
 	if (wl_shm_buffer_get_format(shmbuf) != WL_SHM_FORMAT_ARGB8888)
 		return NULL;
-	if (ev->surface->width > b->cursor_width ||
-	    ev->surface->height > b->cursor_height)
+	if (buffer->width > b->cursor_width ||
+	    buffer->height > b->cursor_height)
 		return NULL;
 
 	output->cursor_view = ev;
@@ -1180,8 +1181,8 @@ cursor_bo_update(struct drm_backend *b, struct gbm_bo *bo,
 
 	assert(buffer && buffer->shm_buffer);
 	assert(buffer->shm_buffer == wl_shm_buffer_get(buffer->resource));
-	assert(ev->surface->width <= b->cursor_width);
-	assert(ev->surface->height <= b->cursor_height);
+	assert(buffer->width <= b->cursor_width);
+	assert(buffer->height <= b->cursor_height);
 
 	memset(buf, 0, sizeof buf);
 	stride = wl_shm_buffer_get_stride(buffer->shm_buffer);
@@ -1191,7 +1192,7 @@ cursor_bo_update(struct drm_backend *b, struct gbm_bo *bo,
 	for (i = 0; i < ev->surface->height; i++)
 		memcpy(buf + i * b->cursor_width,
 		       s + i * stride,
-		       ev->surface->width * 4);
+		       buffer->width * 4);
 	wl_shm_buffer_end_access(buffer->shm_buffer);
 
 	if (gbm_bo_write(bo, buf, sizeof buf) < 0)
@@ -1292,8 +1293,8 @@ drm_assign_planes(struct weston_output *output_base)
 		if (b->use_pixman ||
 		    (es->buffer_ref.buffer &&
 		    (!wl_shm_buffer_get(es->buffer_ref.buffer->resource) ||
-		     (ev->surface->width <= b->cursor_width &&
-		      ev->surface->height <= b->cursor_height))))
+		     (es->buffer_ref.buffer->width <= b->cursor_width &&
+		      es->buffer_ref.buffer->height <= b->cursor_height))))
 			es->keep_buffer = true;
 		else
 			es->keep_buffer = false;
-- 
2.10.2