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

4 files changed, 9 insertions, 9 deletions

diff --git a/source/blender/editors/space_buttons/buttons_context.c b/source/blender/editors/space_buttons/buttons_context.c
index bb381e0dd1e..a6584966643 100644
--- a/source/blender/editors/space_buttons/buttons_context.c
+++ b/source/blender/editors/space_buttons/buttons_context.c
@@ -76,7 +76,7 @@ static int set_pointer_type(ButsContextPath *path, bContextDataResult *result, S
     ptr = &path->ptr[a];
 
     if (RNA_struct_is_a(ptr->type, type)) {
-      CTX_data_pointer_set(result, ptr->id.data, ptr->type, ptr->data);
+      CTX_data_pointer_set(result, ptr->owner_id, ptr->type, ptr->data);
       return 1;
     }
   }
@@ -894,7 +894,7 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
 
     if (ct->user && ct->user->ptr.data) {
       ButsTextureUser *user = ct->user;
-      CTX_data_pointer_set(result, user->ptr.id.data, user->ptr.type, user->ptr.data);
+      CTX_data_pointer_set(result, user->ptr.owner_id, user->ptr.type, user->ptr.data);
     }
 
     return 1;
@@ -982,7 +982,7 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
     PointerRNA *ptr = get_pointer_type(path, &RNA_ParticleSettings);
 
     if (ptr && ptr->data) {
-      CTX_data_pointer_set(result, ptr->id.data, &RNA_ParticleSettings, ptr->data);
+      CTX_data_pointer_set(result, ptr->owner_id, &RNA_ParticleSettings, ptr->data);
       return 1;
     }
     else {
@@ -991,7 +991,7 @@ int buttons_context(const bContext *C, const char *member, bContextDataResult *r
 
       if (ptr && ptr->data) {
         ParticleSettings *part = ((ParticleSystem *)ptr->data)->part;
-        CTX_data_pointer_set(result, ptr->id.data, &RNA_ParticleSettings, part);
+        CTX_data_pointer_set(result, ptr->owner_id, &RNA_ParticleSettings, part);
         return 1;
       }
     }
@@ -1249,8 +1249,8 @@ ID *buttons_context_id_path(const bContext *C)
         }
       }
 
-      if (ptr->id.data) {
-        return ptr->id.data;
+      if (ptr->owner_id) {
+        return ptr->owner_id;
       }
     }
   }
diff --git a/source/blender/editors/space_buttons/buttons_ops.c b/source/blender/editors/space_buttons/buttons_ops.c
index 500efe4bb4d..3ea6d183969 100644
--- a/source/blender/editors/space_buttons/buttons_ops.c
+++ b/source/blender/editors/space_buttons/buttons_ops.c
@@ -103,7 +103,7 @@ static int file_browse_exec(bContext *C, wmOperator *op)
   /* add slash for directories, important for some properties */
   if (RNA_property_subtype(fbo->prop) == PROP_DIRPATH) {
     const bool is_relative = RNA_boolean_get(op->ptr, "relative_path");
-    id = fbo->ptr.id.data;
+    id = fbo->ptr.owner_id;
 
     BLI_strncpy(path, str, FILE_MAX);
     BLI_path_abs(path, id ? ID_BLEND_PATH(bmain, id) : BKE_main_blendfile_path(bmain));
diff --git a/source/blender/editors/space_buttons/buttons_texture.c b/source/blender/editors/space_buttons/buttons_texture.c
index 87ea011e0a7..03c8fbb4e66 100644
--- a/source/blender/editors/space_buttons/buttons_texture.c
+++ b/source/blender/editors/space_buttons/buttons_texture.c
@@ -385,7 +385,7 @@ static void template_texture_select(bContext *C, void *user_p, void *UNUSED(arg)
     if (user->ptr.type == &RNA_ParticleSettingsTextureSlot) {
       /* stupid exception for particle systems which still uses influence
        * from the old texture system, set the active texture slots as well */
-      ParticleSettings *part = user->ptr.id.data;
+      ParticleSettings *part = (ParticleSettings *)user->ptr.owner_id;
       int a;
 
       for (a = 0; a < MAX_MTEX; a++) {
diff --git a/source/blender/editors/space_buttons/space_buttons.c b/source/blender/editors/space_buttons/space_buttons.c
index 129f249d7d0..e3a2a4423f0 100644
--- a/source/blender/editors/space_buttons/space_buttons.c
+++ b/source/blender/editors/space_buttons/space_buttons.c
@@ -561,7 +561,7 @@ static void buttons_id_remap(ScrArea *UNUSED(sa), SpaceLink *slink, ID *old_id,
     int i;
 
     for (i = 0; i < path->len; i++) {
-      if (path->ptr[i].id.data == old_id) {
+      if (path->ptr[i].owner_id == old_id) {
         break;
       }
     }