Workspace: Fix crash on preview, and sanitize placeholder functions

This commit effectively makes workspace switching useless as far as the
active scene layer goes.

The functions from the scene layer API to get the correct scene layer
from "context" were a placeholder to be addressed by the workspace
commit.

When workspace was merged, however G.main was used as a replacement to pass the
correct argument for the functions. As it turned out (surprise!) this
leads to crash on render preview.

We need to get rid of:
* BKE_scene_layer_context_active_ex_PLACEHOLDER
* BKE_scene_layer_context_active_PLACEHOLDER

And either use SceneLayer explicitly or replace it by:
* BKE_scene_layer_from_workspace_get

7 files changed, 9 insertions, 10 deletions

diff --git a/source/blender/editors/render/render_preview.c b/source/blender/editors/render/render_preview.c
index 7292856567f..1a3d1ce083e 100644
--- a/source/blender/editors/render/render_preview.c
+++ b/source/blender/editors/render/render_preview.c
@@ -329,7 +329,7 @@ static Scene *preview_prepare_scene(Main *bmain, Scene *scene, ID *id, int id_ty
 
 	sce = preview_get_scene(pr_main);
 	if (sce) {
-		SceneLayer *scene_layer = BKE_scene_layer_render_active(sce);
+		SceneLayer *scene_layer = BKE_scene_layer_from_scene_get(sce);
 
 		/* this flag tells render to not execute depsgraph or ipos etc */
 		sce->r.scemode |= R_BUTS_PREVIEW;
diff --git a/source/blender/editors/render/render_shading.c b/source/blender/editors/render/render_shading.c
index 43e66fae56c..2cdd49b3113 100644
--- a/source/blender/editors/render/render_shading.c
+++ b/source/blender/editors/render/render_shading.c
@@ -656,7 +656,7 @@ static int render_layer_remove_exec(bContext *C, wmOperator *UNUSED(op))
 {
 	Main *bmain = CTX_data_main(C);
 	Scene *scene = CTX_data_scene(C);
-	SceneLayer *sl = BKE_scene_layer_context_active(scene);
+	SceneLayer *sl = BKE_scene_layer_context_active_PLACEHOLDER(scene);
 
 	if (!ED_scene_render_layer_delete(bmain, scene, sl, NULL)) {
 		return OPERATOR_CANCELLED;
diff --git a/source/blender/editors/screen/screen_context.c b/source/blender/editors/screen/screen_context.c
index 3c7ea9a0f7e..aec32ff2dff 100644
--- a/source/blender/editors/screen/screen_context.c
+++ b/source/blender/editors/screen/screen_context.c
@@ -87,9 +87,8 @@ int ed_screen_context(const bContext *C, const char *member, bContextDataResult
 	bScreen *sc = CTX_wm_screen(C);
 	ScrArea *sa = CTX_wm_area(C);
 	Scene *scene = WM_window_get_active_scene(win);
-	/* can't call BKE_scene_layer_context_active here, it uses G.main->wm which might be NULL on file read. */
 	WorkSpace *workspace = BKE_workspace_active_get(win->workspace_hook);
-	SceneLayer *sl = BKE_workspace_render_layer_get(workspace);
+	SceneLayer *sl = BKE_scene_layer_from_workspace_get(workspace);
 	Object *obedit = scene->obedit;
 	Object *obact = sl->basact ? sl->basact->object : NULL;
 
diff --git a/source/blender/editors/space_buttons/buttons_context.c b/source/blender/editors/space_buttons/buttons_context.c
index 2460ba3fc9f..f6c15f4d030 100644
--- a/source/blender/editors/space_buttons/buttons_context.c
+++ b/source/blender/editors/space_buttons/buttons_context.c
@@ -182,7 +182,7 @@ static int buttons_context_path_object(ButsContextPath *path)
 	else if (buttons_context_path_scene(path)) {
 		scene = path->ptr[path->len - 1].data;
 
-		SceneLayer *sl = BKE_scene_layer_context_active(scene);
+		SceneLayer *sl = BKE_scene_layer_context_active_PLACEHOLDER(scene);
 		ob = (sl->basact) ? sl->basact->object : NULL;
 
 		if (ob) {
diff --git a/source/blender/editors/space_image/space_image.c b/source/blender/editors/space_image/space_image.c
index 4b06cbe6b33..58fb75edd84 100644
--- a/source/blender/editors/space_image/space_image.c
+++ b/source/blender/editors/space_image/space_image.c
@@ -536,7 +536,7 @@ static void image_listener(bScreen *UNUSED(sc), ScrArea *sa, wmNotifier *wmn, co
 				case ND_TRANSFORM:
 				case ND_MODIFIER:
 				{
-					SceneLayer *sl = BKE_scene_layer_context_active(scene);
+					SceneLayer *sl = BKE_scene_layer_context_active_PLACEHOLDER(scene);
 					Object *ob = OBACT_NEW;
 					if (ob && (ob == wmn->reference) && (ob->mode & OB_MODE_EDIT)) {
 						if (sima->lock && (sima->flag & SI_DRAWSHADOW)) {
diff --git a/source/blender/editors/space_outliner/outliner_tree.c b/source/blender/editors/space_outliner/outliner_tree.c
index a87884f6615..568927425a9 100644
--- a/source/blender/editors/space_outliner/outliner_tree.c
+++ b/source/blender/editors/space_outliner/outliner_tree.c
@@ -1944,7 +1944,7 @@ void outliner_build_tree(Main *mainvar, Scene *scene, SceneLayer *sl, SpaceOops
 		outliner_add_orphaned_datablocks(mainvar, soops);
 	}
 	else if (soops->outlinevis == SO_ACT_LAYER) {
-		outliner_add_collections_act_layer(soops, BKE_scene_layer_context_active(scene));
+		outliner_add_collections_act_layer(soops, BKE_scene_layer_context_active_PLACEHOLDER(scene));
 	}
 	else if (soops->outlinevis == SO_COLLECTIONS) {
 		outliner_add_collections_master(soops, scene);
diff --git a/source/blender/editors/space_view3d/view3d_draw_legacy.c b/source/blender/editors/space_view3d/view3d_draw_legacy.c
index 15424854814..a7ed6fcc30c 100644
--- a/source/blender/editors/space_view3d/view3d_draw_legacy.c
+++ b/source/blender/editors/space_view3d/view3d_draw_legacy.c
@@ -1198,7 +1198,7 @@ void ED_view3d_draw_depth_gpencil(Scene *scene, ARegion *ar, View3D *v3d)
 void ED_view3d_draw_depth_loop(Scene *scene, ARegion *ar, View3D *v3d)
 {
 	Base *base;
-	SceneLayer *sl = BKE_scene_layer_context_active(scene);
+	SceneLayer *sl = BKE_scene_layer_context_active_PLACEHOLDER(scene);
 	/* no need for color when drawing depth buffer */
 	const short dflag_depth = DRAW_CONSTCOLOR;
 
@@ -1422,7 +1422,7 @@ static void gpu_update_lamps_shadows_world(Scene *scene, View3D *v3d)
 
 		/* no need to call ED_view3d_draw_offscreen_init since shadow buffers were already updated */
 		ED_view3d_draw_offscreen(
-		            scene, BKE_scene_layer_context_active(scene), v3d, &ar, winsize, winsize, viewmat, winmat,
+		            scene, BKE_scene_layer_context_active_PLACEHOLDER(scene), v3d, &ar, winsize, winsize, viewmat, winmat,
 		            false, false, true,
 		            NULL, NULL, NULL, NULL);
 		GPU_lamp_shadow_buffer_unbind(shadow->lamp);
@@ -1499,7 +1499,7 @@ static void view3d_draw_objects(
         const char **grid_unit,
         const bool do_bgpic, const bool draw_offscreen, GPUFX *fx)
 {
-	SceneLayer *sl = C ? CTX_data_scene_layer(C) : BKE_scene_layer_render_active(scene);
+	SceneLayer *sl = C ? CTX_data_scene_layer(C) : BKE_scene_layer_from_scene_get(scene);
 	RegionView3D *rv3d = ar->regiondata;
 	Base *base;
 	const bool do_camera_frame = !draw_offscreen;