Cleanup: use plural names for Main lists

Convention was not to but after discussion on 918941483f7e we agree its
best to change the convention.

Names now mostly follow RNA.

Some exceptions:

- Use 'nodetrees' instead of 'nodegroups'
  since the struct is called NodeTree.
- Use 'gpencils' instead of 'grease_pencil'
  since 'gpencil' is a common abbreviation in the C code.

Other exceptions:

- Leave 'wm' as it's a list of one.
- Leave 'ipo' as is for versioning.

2 files changed, 3 insertions, 3 deletions

diff --git a/source/blender/nodes/composite/node_composite_tree.c b/source/blender/nodes/composite/node_composite_tree.c
index e2cfb4cd24c..ffa3cf363c9 100644
--- a/source/blender/nodes/composite/node_composite_tree.c
+++ b/source/blender/nodes/composite/node_composite_tree.c
@@ -276,7 +276,7 @@ void ntreeCompositTagRender(Scene *curscene)
 	/* XXX Think using G_MAIN here is valid, since you want to update current file's scene nodes,
 	 * not the ones in temp main generated for rendering?
 	 * This is still rather weak though, ideally render struct would store own main AND original G_MAIN... */
-	for (sce = G_MAIN->scene.first; sce; sce = sce->id.next) {
+	for (sce = G_MAIN->scenes.first; sce; sce = sce->id.next) {
 		if (sce->nodetree) {
 			bNode *node;
 
diff --git a/source/blender/nodes/composite/nodes/node_composite_image.c b/source/blender/nodes/composite/nodes/node_composite_image.c
index 8c0a277668f..37652daa312 100644
--- a/source/blender/nodes/composite/nodes/node_composite_image.c
+++ b/source/blender/nodes/composite/nodes/node_composite_image.c
@@ -216,7 +216,7 @@ static void cmp_node_rlayer_create_outputs_cb(void *UNUSED(userdata), Scene *sce
 	 * unless we want to register that for every other temp Main we could generate??? */
 	ntreeCompositRegisterPass(scene->nodetree, scene, view_layer, name, type);
 
-	for (Scene *sce = G_MAIN->scene.first; sce; sce = sce->id.next) {
+	for (Scene *sce = G_MAIN->scenes.first; sce; sce = sce->id.next) {
 		if (sce->nodetree && sce != scene) {
 			ntreeCompositRegisterPass(sce->nodetree, scene, view_layer, name, type);
 		}
@@ -409,7 +409,7 @@ static bool node_composit_poll_rlayers(bNodeType *UNUSED(ntype), bNodeTree *ntre
 		 * Render layers node can only be used in local scene->nodetree,
 		 * since it directly links to the scene.
 		 */
-		for (scene = G.main->scene.first; scene; scene = scene->id.next)
+		for (scene = G.main->scenes.first; scene; scene = scene->id.next)
 			if (scene->nodetree == ntree)
 				break;