ID-Remap - Step one: core work (cleanup and rework of generic ID datablock handling).

This commit changes a lot of how IDs are handled internally, especially the unlinking/freeing
processes. So far, this was very fuzy, to summarize cleanly deleting or replacing a datablock
was pretty much impossible, except for a few special cases.

Also, unlinking was handled by each datatype, in a rather messy and prone-to-errors way (quite
a few ID usages were missed or wrongly handled that way).

One of the main goal of id-remap branch was to cleanup this, and fatorize ID links handling
by using library_query utils to allow generic handling of those, which is now the case
(now, generic ID links handling is only "knwon" from readfile.c and library_query.c).

This commit also adds backends to allow live replacement and deletion of datablocks in Blender
(so-called 'remapping' process, where we replace all usages of a given ID pointer by a new one,
or NULL one in case of unlinking).

This will allow nice new features, like ability to easily reload or relocate libraries, real immediate
deletion of datablocks in blender, replacement of one datablock by another, etc.
Some of those are for next commits.

A word of warning: this commit is highly risky, because it affects potentially a lot in Blender core.
Though it was tested rather deeply, being totally impossible to check all possible ID usage cases,
it's likely there are some remaining issues and bugs in new code... Please report them! ;)

Review task: D2027 (https://developer.blender.org/D2027).
Reviewed by campbellbarton, thanks a bunch.

5 files changed, 3 insertions, 11 deletions

diff --git a/source/blender/editors/include/ED_buttons.h b/source/blender/editors/include/ED_buttons.h
index 9a987d7618c..64c16605dec 100644
--- a/source/blender/editors/include/ED_buttons.h
+++ b/source/blender/editors/include/ED_buttons.h
@@ -37,6 +37,4 @@ bool ED_texture_context_check_particles(const struct bContext *C);
 bool ED_texture_context_check_linestyle(const struct bContext *C);
 bool ED_texture_context_check_others(const struct bContext *C);
 
-void ED_buttons_id_unref(struct SpaceButs *sbuts, const struct ID *id);
-
 #endif /*  __ED_BUTTONS_H__ */
diff --git a/source/blender/editors/include/ED_node.h b/source/blender/editors/include/ED_node.h
index 7fe9a0c320c..f7b9d6b4f9e 100644
--- a/source/blender/editors/include/ED_node.h
+++ b/source/blender/editors/include/ED_node.h
@@ -103,8 +103,6 @@ void ED_node_set_active(struct Main *bmain, struct bNodeTree *ntree, struct bNod
 
 void ED_node_composite_job(const struct bContext *C, struct bNodeTree *nodetree, struct Scene *scene_owner);
 
-void ED_node_id_unref(struct SpaceNode *snode, const ID *id);
-
 /* node_ops.c */
 void ED_operatormacros_node(void);
 
diff --git a/source/blender/editors/include/ED_outliner.h b/source/blender/editors/include/ED_outliner.h
index af4af8e2f5d..73ee2542247 100644
--- a/source/blender/editors/include/ED_outliner.h
+++ b/source/blender/editors/include/ED_outliner.h
@@ -27,10 +27,4 @@
 #ifndef __ED_OUTLINER_H__
 #define __ED_OUTLINER_H__
 
-struct ID;
-struct SpaceOops;
-
-/* Used to check whether a given texture context is valid in current context. */
-void ED_outliner_id_unref(struct SpaceOops *so, const struct ID *id);
-
 #endif /*  __ED_OUTLINER_H__ */
diff --git a/source/blender/editors/include/ED_util.h b/source/blender/editors/include/ED_util.h
index f143ea478c6..b6b80b93e0b 100644
--- a/source/blender/editors/include/ED_util.h
+++ b/source/blender/editors/include/ED_util.h
@@ -43,7 +43,7 @@ void    ED_editors_exit(struct bContext *C);
 
 bool    ED_editors_flush_edits(const struct bContext *C, bool for_render);
 
-void ED_spacedata_id_unref(struct SpaceLink *sl, const struct ID *id);
+void    ED_spacedata_id_remap(struct ScrArea *sa, struct SpaceLink *sl, struct ID *old_id, struct ID *new_id);
 
 void    ED_OT_flush_edits(struct wmOperatorType *ot);
 
diff --git a/source/blender/editors/include/ED_view3d.h b/source/blender/editors/include/ED_view3d.h
index c23c2eed890..baab6b6100d 100644
--- a/source/blender/editors/include/ED_view3d.h
+++ b/source/blender/editors/include/ED_view3d.h
@@ -403,4 +403,6 @@ void ED_view3d_shade_update(struct Main *bmain, struct Scene *scene, struct View
 #define V3D_IS_ZBUF(v3d) \
 	(((v3d)->flag & V3D_ZBUF_SELECT) && ((v3d)->drawtype > OB_WIRE))
 
+void ED_view3d_id_remap(struct View3D *v3d, const struct ID *old_id, struct ID *new_id);
+
 #endif /* __ED_VIEW3D_H__ */