RNA: Cleanup PointerRNA struct

The old layout of `PointerRNA` was confusing for historic reasons:
```
typedef struct PointerRNA {
  struct {
    void *data;
  } id;

  struct StructRNA *type;
  void *data;
} PointerRNA;
```

This patch updates it to:
```
typedef struct PointerRNA {
  struct ID *owner_id;
  struct StructRNA *type;
  void *data;
} PointerRNA;
```

Throughout the code base `id.data` was replaced with `owner_id`.
Furthermore, many explicit pointer type casts were added which
were implicit before. Some type casts to `ID *` were removed.

Reviewers: brecht, campbellbarton

Differential Revision: https://developer.blender.org/D5558

1 files changed, 4 insertions, 4 deletions

diff --git a/source/blender/editors/render/render_shading.c b/source/blender/editors/render/render_shading.c
index 01740c13c9d..9f13431f25a 100644
--- a/source/blender/editors/render/render_shading.c
+++ b/source/blender/editors/render/render_shading.c
@@ -1836,7 +1836,7 @@ void SCENE_OT_freestyle_stroke_material_create(wmOperatorType *ot)
 
 static int texture_slot_move_exec(bContext *C, wmOperator *op)
 {
-  ID *id = CTX_data_pointer_get_type(C, "texture_slot", &RNA_TextureSlot).id.data;
+  ID *id = CTX_data_pointer_get_type(C, "texture_slot", &RNA_TextureSlot).owner_id;
 
   if (id) {
     MTex **mtex_ar, *mtexswap;
@@ -2031,7 +2031,7 @@ static void paste_mtex_copybuf(ID *id)
 
 static int copy_mtex_exec(bContext *C, wmOperator *UNUSED(op))
 {
-  ID *id = CTX_data_pointer_get_type(C, "texture_slot", &RNA_TextureSlot).id.data;
+  ID *id = CTX_data_pointer_get_type(C, "texture_slot", &RNA_TextureSlot).owner_id;
 
   if (id == NULL) {
     /* copying empty slot */
@@ -2046,7 +2046,7 @@ static int copy_mtex_exec(bContext *C, wmOperator *UNUSED(op))
 
 static bool copy_mtex_poll(bContext *C)
 {
-  ID *id = CTX_data_pointer_get_type(C, "texture_slot", &RNA_TextureSlot).id.data;
+  ID *id = CTX_data_pointer_get_type(C, "texture_slot", &RNA_TextureSlot).owner_id;
 
   return (id != NULL);
 }
@@ -2069,7 +2069,7 @@ void TEXTURE_OT_slot_copy(wmOperatorType *ot)
 
 static int paste_mtex_exec(bContext *C, wmOperator *UNUSED(op))
 {
-  ID *id = CTX_data_pointer_get_type(C, "texture_slot", &RNA_TextureSlot).id.data;
+  ID *id = CTX_data_pointer_get_type(C, "texture_slot", &RNA_TextureSlot).owner_id;
 
   if (id == NULL) {
     Material *ma = CTX_data_pointer_get_type(C, "material", &RNA_Material).data;