Cleanup: Blendwrite: Move code deciding if an ID should be written out of ID callbacks.

This was not really useful, and added estra useless steps in case and ID
should not actually be written.

Further more, it prevented clearing the usercount on write, which can be
cause a false positive 'chanhged' detection in undo/redo case.

1 files changed, 69 insertions, 74 deletions

diff --git a/source/blender/blenkernel/intern/mesh.c b/source/blender/blenkernel/intern/mesh.c
index e99670fc488..8257e54c618 100644
--- a/source/blender/blenkernel/intern/mesh.c
+++ b/source/blender/blenkernel/intern/mesh.c
@@ -179,95 +179,90 @@ static void mesh_blend_write(BlendWriter *writer, ID *id, const void *id_address
 {
   Mesh *mesh = (Mesh *)id;
   const bool is_undo = BLO_write_is_undo(writer);
-  if (mesh->id.us > 0 || is_undo) {
-    CustomDataLayer *vlayers = NULL, vlayers_buff[CD_TEMP_CHUNK_SIZE];
-    CustomDataLayer *elayers = NULL, elayers_buff[CD_TEMP_CHUNK_SIZE];
-    CustomDataLayer *flayers = NULL, flayers_buff[CD_TEMP_CHUNK_SIZE];
-    CustomDataLayer *llayers = NULL, llayers_buff[CD_TEMP_CHUNK_SIZE];
-    CustomDataLayer *players = NULL, players_buff[CD_TEMP_CHUNK_SIZE];
-
-    /* cache only - don't write */
-    mesh->mface = NULL;
-    mesh->totface = 0;
-    memset(&mesh->fdata, 0, sizeof(mesh->fdata));
-    memset(&mesh->runtime, 0, sizeof(mesh->runtime));
-    flayers = flayers_buff;
-
-    /* Do not store actual geometry data in case this is a library override ID. */
-    if (ID_IS_OVERRIDE_LIBRARY(mesh) && !is_undo) {
-      mesh->mvert = NULL;
-      mesh->totvert = 0;
-      memset(&mesh->vdata, 0, sizeof(mesh->vdata));
-      vlayers = vlayers_buff;
-
-      mesh->medge = NULL;
-      mesh->totedge = 0;
-      memset(&mesh->edata, 0, sizeof(mesh->edata));
-      elayers = elayers_buff;
-
-      mesh->mloop = NULL;
-      mesh->totloop = 0;
-      memset(&mesh->ldata, 0, sizeof(mesh->ldata));
-      llayers = llayers_buff;
-
-      mesh->mpoly = NULL;
-      mesh->totpoly = 0;
-      memset(&mesh->pdata, 0, sizeof(mesh->pdata));
-      players = players_buff;
-    }
-    else {
-      CustomData_blend_write_prepare(
-          &mesh->vdata, &vlayers, vlayers_buff, ARRAY_SIZE(vlayers_buff));
-      CustomData_blend_write_prepare(
-          &mesh->edata, &elayers, elayers_buff, ARRAY_SIZE(elayers_buff));
-      CustomData_blend_write_prepare(
-          &mesh->ldata, &llayers, llayers_buff, ARRAY_SIZE(llayers_buff));
-      CustomData_blend_write_prepare(
-          &mesh->pdata, &players, players_buff, ARRAY_SIZE(players_buff));
-    }
 
-    BLO_write_id_struct(writer, Mesh, id_address, &mesh->id);
-    BKE_id_blend_write(writer, &mesh->id);
+  CustomDataLayer *vlayers = NULL, vlayers_buff[CD_TEMP_CHUNK_SIZE];
+  CustomDataLayer *elayers = NULL, elayers_buff[CD_TEMP_CHUNK_SIZE];
+  CustomDataLayer *flayers = NULL, flayers_buff[CD_TEMP_CHUNK_SIZE];
+  CustomDataLayer *llayers = NULL, llayers_buff[CD_TEMP_CHUNK_SIZE];
+  CustomDataLayer *players = NULL, players_buff[CD_TEMP_CHUNK_SIZE];
 
-    /* direct data */
-    if (mesh->adt) {
-      BKE_animdata_blend_write(writer, mesh->adt);
-    }
+  /* cache only - don't write */
+  mesh->mface = NULL;
+  mesh->totface = 0;
+  memset(&mesh->fdata, 0, sizeof(mesh->fdata));
+  memset(&mesh->runtime, 0, sizeof(mesh->runtime));
+  flayers = flayers_buff;
+
+  /* Do not store actual geometry data in case this is a library override ID. */
+  if (ID_IS_OVERRIDE_LIBRARY(mesh) && !is_undo) {
+    mesh->mvert = NULL;
+    mesh->totvert = 0;
+    memset(&mesh->vdata, 0, sizeof(mesh->vdata));
+    vlayers = vlayers_buff;
+
+    mesh->medge = NULL;
+    mesh->totedge = 0;
+    memset(&mesh->edata, 0, sizeof(mesh->edata));
+    elayers = elayers_buff;
+
+    mesh->mloop = NULL;
+    mesh->totloop = 0;
+    memset(&mesh->ldata, 0, sizeof(mesh->ldata));
+    llayers = llayers_buff;
+
+    mesh->mpoly = NULL;
+    mesh->totpoly = 0;
+    memset(&mesh->pdata, 0, sizeof(mesh->pdata));
+    players = players_buff;
+  }
+  else {
+    CustomData_blend_write_prepare(&mesh->vdata, &vlayers, vlayers_buff, ARRAY_SIZE(vlayers_buff));
+    CustomData_blend_write_prepare(&mesh->edata, &elayers, elayers_buff, ARRAY_SIZE(elayers_buff));
+    CustomData_blend_write_prepare(&mesh->ldata, &llayers, llayers_buff, ARRAY_SIZE(llayers_buff));
+    CustomData_blend_write_prepare(&mesh->pdata, &players, players_buff, ARRAY_SIZE(players_buff));
+  }
+
+  BLO_write_id_struct(writer, Mesh, id_address, &mesh->id);
+  BKE_id_blend_write(writer, &mesh->id);
 
-    BKE_defbase_blend_write(writer, &mesh->vertex_group_names);
+  /* direct data */
+  if (mesh->adt) {
+    BKE_animdata_blend_write(writer, mesh->adt);
+  }
+
+  BKE_defbase_blend_write(writer, &mesh->vertex_group_names);
 
-    BLO_write_pointer_array(writer, mesh->totcol, mesh->mat);
-    BLO_write_raw(writer, sizeof(MSelect) * mesh->totselect, mesh->mselect);
+  BLO_write_pointer_array(writer, mesh->totcol, mesh->mat);
+  BLO_write_raw(writer, sizeof(MSelect) * mesh->totselect, mesh->mselect);
 
-    CustomData_blend_write(
-        writer, &mesh->vdata, vlayers, mesh->totvert, CD_MASK_MESH.vmask, &mesh->id);
-    CustomData_blend_write(
-        writer, &mesh->edata, elayers, mesh->totedge, CD_MASK_MESH.emask, &mesh->id);
-    /* fdata is really a dummy - written so slots align */
-    CustomData_blend_write(
-        writer, &mesh->fdata, flayers, mesh->totface, CD_MASK_MESH.fmask, &mesh->id);
-    CustomData_blend_write(
-        writer, &mesh->ldata, llayers, mesh->totloop, CD_MASK_MESH.lmask, &mesh->id);
-    CustomData_blend_write(
-        writer, &mesh->pdata, players, mesh->totpoly, CD_MASK_MESH.pmask, &mesh->id);
+  CustomData_blend_write(
+      writer, &mesh->vdata, vlayers, mesh->totvert, CD_MASK_MESH.vmask, &mesh->id);
+  CustomData_blend_write(
+      writer, &mesh->edata, elayers, mesh->totedge, CD_MASK_MESH.emask, &mesh->id);
+  /* fdata is really a dummy - written so slots align */
+  CustomData_blend_write(
+      writer, &mesh->fdata, flayers, mesh->totface, CD_MASK_MESH.fmask, &mesh->id);
+  CustomData_blend_write(
+      writer, &mesh->ldata, llayers, mesh->totloop, CD_MASK_MESH.lmask, &mesh->id);
+  CustomData_blend_write(
+      writer, &mesh->pdata, players, mesh->totpoly, CD_MASK_MESH.pmask, &mesh->id);
 
-    /* Free temporary data */
+  /* Free temporary data */
 
-/* Free custom-data layers, when not assigned a buffer value. */
+  /* Free custom-data layers, when not assigned a buffer value. */
 #define CD_LAYERS_FREE(id) \
   if (id && id != id##_buff) { \
     MEM_freeN(id); \
   } \
   ((void)0)
 
-    CD_LAYERS_FREE(vlayers);
-    CD_LAYERS_FREE(elayers);
-    // CD_LAYER_FREE(flayers); /* Never allocated. */
-    CD_LAYERS_FREE(llayers);
-    CD_LAYERS_FREE(players);
+  CD_LAYERS_FREE(vlayers);
+  CD_LAYERS_FREE(elayers);
+  // CD_LAYER_FREE(flayers); /* Never allocated. */
+  CD_LAYERS_FREE(llayers);
+  CD_LAYERS_FREE(players);
 
 #undef CD_LAYERS_FREE
-  }
 }
 
 static void mesh_blend_read_data(BlendDataReader *reader, ID *id)