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, 47 insertions, 39 deletions

diff --git a/source/blender/editors/space_outliner/outliner_draw.c b/source/blender/editors/space_outliner/outliner_draw.c
index 554009da8be..43e9c262172 100644
--- a/source/blender/editors/space_outliner/outliner_draw.c
+++ b/source/blender/editors/space_outliner/outliner_draw.c
@@ -502,6 +502,11 @@ static void namebutton_cb(bContext *C, void *tsep, char *oldname)
 					BKE_reportf(CTX_wm_reports(C), RPT_ERROR,
 					            "Library path '%s' does not exist, correct this before saving", expanded);
 				}
+				else if (lib->id.tag & LIB_TAG_MISSING) {
+					BKE_reportf(CTX_wm_reports(C), RPT_INFO,
+					            "Library path '%s' is now valid, please reload the library", expanded);
+					lib->id.tag &= ~LIB_TAG_MISSING;
+				}
 			}
 		}
 		else {
diff --git a/source/blender/editors/space_outliner/outliner_edit.c b/source/blender/editors/space_outliner/outliner_edit.c
index 2627b978b40..8cee696b2ac 100644
--- a/source/blender/editors/space_outliner/outliner_edit.c
+++ b/source/blender/editors/space_outliner/outliner_edit.c
@@ -2079,36 +2079,3 @@ void OUTLINER_OT_group_link(wmOperatorType *ot)
 	/* properties */
 	RNA_def_string(ot->srna, "object", "Object", MAX_ID_NAME, "Object", "Target Object");
 }
-
-/******** Utils to clear any ref to freed ID... **********/
-
-void ED_outliner_id_unref(SpaceOops *so, const ID *id)
-{
-	/* Some early out checks. */
-	if (!TREESTORE_ID_TYPE(id)) {
-		return;  /* ID type is not used by outilner... */
-	}
-
-	if (so->search_tse.id == id) {
-		so->search_tse.id = NULL;
-	}
-
-	if (so->treestore) {
-		TreeStoreElem *tselem;
-		BLI_mempool_iter iter;
-		bool changed = false;
-
-		BLI_mempool_iternew(so->treestore, &iter);
-		while ((tselem = BLI_mempool_iterstep(&iter))) {
-			if (tselem->id == id) {
-				tselem->id = NULL;
-				changed = true;
-			}
-		}
-		if (so->treehash && changed) {
-			/* rebuild hash table, because it depends on ids too */
-			/* postpone a full rebuild because this can be called many times on-free */
-			so->storeflag |= SO_TREESTORE_REBUILD;
-		}
-	}
-}
diff --git a/source/blender/editors/space_outliner/outliner_intern.h b/source/blender/editors/space_outliner/outliner_intern.h
index dc81be7a8e0..2e46ffa6437 100644
--- a/source/blender/editors/space_outliner/outliner_intern.h
+++ b/source/blender/editors/space_outliner/outliner_intern.h
@@ -230,6 +230,7 @@ void OUTLINER_OT_object_operation(struct wmOperatorType *ot);
 void OUTLINER_OT_group_operation(struct wmOperatorType *ot);
 void OUTLINER_OT_lib_operation(struct wmOperatorType *ot);
 void OUTLINER_OT_id_operation(struct wmOperatorType *ot);
+void OUTLINER_OT_id_remap(struct wmOperatorType *ot);
 void OUTLINER_OT_data_operation(struct wmOperatorType *ot);
 void OUTLINER_OT_animdata_operation(struct wmOperatorType *ot);
 void OUTLINER_OT_action_set(struct wmOperatorType *ot);
diff --git a/source/blender/editors/space_outliner/outliner_tools.c b/source/blender/editors/space_outliner/outliner_tools.c
index 83677b6bd86..2a210e382a2 100644
--- a/source/blender/editors/space_outliner/outliner_tools.c
+++ b/source/blender/editors/space_outliner/outliner_tools.c
@@ -57,6 +57,7 @@
 #include "BKE_fcurve.h"
 #include "BKE_group.h"
 #include "BKE_library.h"
+#include "BKE_library_remap.h"
 #include "BKE_main.h"
 #include "BKE_report.h"
 #include "BKE_scene.h"
@@ -230,7 +231,8 @@ static void unlink_group_cb(
 	}
 	else {
 		Main *bmain = CTX_data_main(C);
-		BKE_group_unlink(bmain, group);
+		BKE_libblock_unlink(bmain, group, false);
+		BKE_libblock_free(bmain, group);
 	}
 }
 
@@ -246,7 +248,7 @@ static void unlink_world_cb(bContext *UNUSED(C), Scene *UNUSED(scene), TreeEleme
 }
 
 static void outliner_do_libdata_operation(
-        bContext *C, Scene *scene, SpaceOops *soops, ListBase *lb, 
+        bContext *C, Scene *scene, SpaceOops *soops, ListBase *lb,
         void (*operation_cb)(bContext *C, Scene *scene, TreeElement *, TreeStoreElem *, TreeStoreElem *, void *),
         void *user_data)
 {
@@ -522,8 +524,7 @@ static void group_instance_cb(bContext *C, Scene *scene, TreeElement *UNUSED(te)
  */
 void outliner_do_object_operation_ex(
         bContext *C, Scene *scene_act, SpaceOops *soops, ListBase *lb,
-        void (*operation_cb)(bContext *C, Scene *scene, TreeElement *,
-                             TreeStoreElem *, TreeStoreElem *, void *),
+        void (*operation_cb)(bContext *, Scene *, TreeElement *, TreeStoreElem *, TreeStoreElem *, void *),
         bool select_recurse)
 {
 	TreeElement *te;
@@ -565,7 +566,7 @@ void outliner_do_object_operation(
 static void clear_animdata_cb(int UNUSED(event), TreeElement *UNUSED(te),
                               TreeStoreElem *tselem, void *UNUSED(arg))
 {
-	BKE_animdata_free(tselem->id);
+	BKE_animdata_free(tselem->id, true);
 }
 
 
diff --git a/source/blender/editors/space_outliner/space_outliner.c b/source/blender/editors/space_outliner/space_outliner.c
index 1dd66366e5d..76bf9c701ed 100644
--- a/source/blender/editors/space_outliner/space_outliner.c
+++ b/source/blender/editors/space_outliner/space_outliner.c
@@ -486,6 +486,39 @@ static SpaceLink *outliner_duplicate(SpaceLink *sl)
 	return (SpaceLink *)soutlinern;
 }
 
+static void outliner_id_remap(ScrArea *UNUSED(sa), SpaceLink *slink, ID *old_id, ID *new_id)
+{
+	SpaceOops *so = (SpaceOops *)slink;
+
+	/* Some early out checks. */
+	if (!TREESTORE_ID_TYPE(old_id)) {
+		return;  /* ID type is not used by outilner... */
+	}
+
+	if (so->search_tse.id == old_id) {
+		so->search_tse.id = new_id;
+	}
+
+	if (so->treestore) {
+		TreeStoreElem *tselem;
+		BLI_mempool_iter iter;
+		bool changed = false;
+
+		BLI_mempool_iternew(so->treestore, &iter);
+		while ((tselem = BLI_mempool_iterstep(&iter))) {
+			if (tselem->id == old_id) {
+				tselem->id = new_id;
+				changed = true;
+			}
+		}
+		if (so->treehash && changed) {
+			/* rebuild hash table, because it depends on ids too */
+			/* postpone a full rebuild because this can be called many times on-free */
+			so->storeflag |= SO_TREESTORE_REBUILD;
+		}
+	}
+}
+
 /* only called once, from space_api/spacetypes.c */
 void ED_spacetype_outliner(void)
 {
@@ -502,7 +535,8 @@ void ED_spacetype_outliner(void)
 	st->operatortypes = outliner_operatortypes;
 	st->keymap = outliner_keymap;
 	st->dropboxes = outliner_dropboxes;
-	
+	st->id_remap = outliner_id_remap;
+
 	/* regions: main window */
 	art = MEM_callocN(sizeof(ARegionType), "spacetype outliner region");
 	art->regionid = RGN_TYPE_WINDOW;