File Browser: Refactor access to the selection parameters struct

* Avoid direct access to `SpaceFile.params`, use a getter instead. This matters
  because once the asset-browser changes are in, there will be an alternative
  selection parameter object. The getter can return the correct one.
* Rename the function to ensure the parameters. The old name
  `ED_fileselect_get_params()` wasn't a mere getter, it would create the
  parameters if necessary. Now we have an actual getter, so better be clear.
* In some instances, I replaced the old "get" function with the new mere
  getter. So the ensure logic is called less often. However, in these cases we
  should be able to assume the selection parameters were created already as
  part of the editor creation routine.

The term "active" in the new function names may seem a bit odd in the current
context, but that is a preparation for the Asset Browser merge as well. Like
said, there will be two file selection parameter objects in the space.

7 files changed, 241 insertions, 219 deletions

diff --git a/source/blender/editors/include/ED_fileselect.h b/source/blender/editors/include/ED_fileselect.h
index 84808416074..a5a8df916d6 100644
--- a/source/blender/editors/include/ED_fileselect.h
+++ b/source/blender/editors/include/ED_fileselect.h
@@ -101,9 +101,9 @@ typedef struct FileSelection {
 struct View2D;
 struct rcti;
 
-struct FileSelectParams *ED_fileselect_get_params(struct SpaceFile *sfile);
+struct FileSelectParams *ED_fileselect_ensure_active_params(struct SpaceFile *sfile);
+struct FileSelectParams *ED_fileselect_get_active_params(const struct SpaceFile *sfile);
 
-short ED_fileselect_set_params(struct SpaceFile *sfile);
 void ED_fileselect_set_params_from_userdef(struct SpaceFile *sfile);
 void ED_fileselect_params_to_userdef(struct SpaceFile *sfile,
                                      const int temp_win_size[],
diff --git a/source/blender/editors/space_file/file_draw.c b/source/blender/editors/space_file/file_draw.c
index 4b277435f63..e3bdda7c480 100644
--- a/source/blender/editors/space_file/file_draw.c
+++ b/source/blender/editors/space_file/file_draw.c
@@ -400,11 +400,12 @@ static void renamebutton_cb(bContext *C, void *UNUSED(arg1), char *oldname)
   wmWindowManager *wm = CTX_wm_manager(C);
   SpaceFile *sfile = (SpaceFile *)CTX_wm_space_data(C);
   ARegion *region = CTX_wm_region(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
 
-  BLI_join_dirfile(orgname, sizeof(orgname), sfile->params->dir, oldname);
-  BLI_strncpy(filename, sfile->params->renamefile, sizeof(filename));
+  BLI_join_dirfile(orgname, sizeof(orgname), params->dir, oldname);
+  BLI_strncpy(filename, params->renamefile, sizeof(filename));
   BLI_filename_make_safe(filename);
-  BLI_join_dirfile(newname, sizeof(newname), sfile->params->dir, filename);
+  BLI_join_dirfile(newname, sizeof(newname), params->dir, filename);
 
   if (!STREQ(orgname, newname)) {
     if (!BLI_exists(newname)) {
@@ -415,8 +416,8 @@ static void renamebutton_cb(bContext *C, void *UNUSED(arg1), char *oldname)
       }
       else {
         /* If rename is successful, scroll to newly renamed entry. */
-        BLI_strncpy(sfile->params->renamefile, filename, sizeof(sfile->params->renamefile));
-        sfile->params->rename_flag = FILE_PARAMS_RENAME_POSTSCROLL_PENDING;
+        BLI_strncpy(params->renamefile, filename, sizeof(params->renamefile));
+        params->rename_flag = FILE_PARAMS_RENAME_POSTSCROLL_PENDING;
 
         if (sfile->smoothscroll_timer != NULL) {
           WM_event_remove_timer(CTX_wm_manager(C), CTX_wm_window(C), sfile->smoothscroll_timer);
@@ -688,7 +689,7 @@ static void draw_details_columns(const FileSelectParams *params,
 void file_draw_list(const bContext *C, ARegion *region)
 {
   SpaceFile *sfile = CTX_wm_space_file(C);
-  FileSelectParams *params = ED_fileselect_get_params(sfile);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   FileLayout *layout = ED_fileselect_get_layout(sfile, region);
   View2D *v2d = &region->v2d;
   struct FileList *files = sfile->files;
@@ -847,26 +848,25 @@ void file_draw_list(const bContext *C, ARegion *region)
     }
 
     if (file_selflag & FILE_SEL_EDITING) {
-      uiBut *but;
       const short width = (params->display == FILE_IMGDISPLAY) ?
                               textwidth :
                               layout->attribute_columns[COLUMN_NAME].width -
                                   ATTRIBUTE_COLUMN_PADDING;
 
-      but = uiDefBut(block,
-                     UI_BTYPE_TEXT,
-                     1,
-                     "",
-                     sx + icon_ofs,
-                     sy - layout->tile_h - 0.15f * UI_UNIT_X,
-                     width - icon_ofs,
-                     textheight,
-                     sfile->params->renamefile,
-                     1.0f,
-                     (float)sizeof(sfile->params->renamefile),
-                     0,
-                     0,
-                     "");
+      uiBut *but = uiDefBut(block,
+                            UI_BTYPE_TEXT,
+                            1,
+                            "",
+                            sx + icon_ofs,
+                            sy - layout->tile_h - 0.15f * UI_UNIT_X,
+                            width - icon_ofs,
+                            textheight,
+                            params->renamefile,
+                            1.0f,
+                            (float)sizeof(params->renamefile),
+                            0,
+                            0,
+                            "");
       UI_but_func_rename_set(but, renamebutton_cb, file);
       UI_but_flag_enable(but, UI_BUT_NO_UTF8); /* allow non utf8 names */
       UI_but_flag_disable(but, UI_BUT_UNDO);
diff --git a/source/blender/editors/space_file/file_ops.c b/source/blender/editors/space_file/file_ops.c
index 93367ad3d3c..b98348307f3 100644
--- a/source/blender/editors/space_file/file_ops.c
+++ b/source/blender/editors/space_file/file_ops.c
@@ -188,7 +188,7 @@ static FileSelect file_select_do(bContext *C, int selected_idx, bool do_diropen)
   Main *bmain = CTX_data_main(C);
   FileSelect retval = FILE_SELECT_NOTHING;
   SpaceFile *sfile = CTX_wm_space_file(C);
-  FileSelectParams *params = ED_fileselect_get_params(sfile);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   int numfiles = filelist_files_ensure(sfile->files);
   const FileDirEntry *file;
 
@@ -302,10 +302,10 @@ static FileSelect file_select(
     bContext *C, const rcti *rect, FileSelType select, bool fill, bool do_diropen)
 {
   SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   FileSelect retval = FILE_SELECT_NOTHING;
   FileSelection sel = file_selection_get(C, rect, fill); /* get the selection */
-  const FileCheckType check_type = (sfile->params->flag & FILE_DIRSEL_ONLY) ? CHECK_DIRS :
-                                                                              CHECK_ALL;
+  const FileCheckType check_type = (params->flag & FILE_DIRSEL_ONLY) ? CHECK_DIRS : CHECK_ALL;
 
   /* flag the files as selected in the filelist */
   filelist_entries_select_index_range_set(
@@ -325,7 +325,7 @@ static FileSelect file_select(
   }
 
   if (select != FILE_SEL_ADD && !file_is_any_selected(sfile->files)) {
-    sfile->params->active_file = -1;
+    params->active_file = -1;
   }
   else if (sel.last >= 0) {
     ARegion *region = CTX_wm_region(C);
@@ -390,7 +390,7 @@ static int file_box_select_modal(bContext *C, wmOperator *op, const wmEvent *eve
 {
   ARegion *region = CTX_wm_region(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
-  FileSelectParams *params = ED_fileselect_get_params(sfile);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   FileSelection sel;
   rcti rect;
 
@@ -521,8 +521,9 @@ static int file_select_invoke(bContext *C, wmOperator *op, const wmEvent *event)
     return OPERATOR_CANCELLED | OPERATOR_PASS_THROUGH;
   }
 
-  if (sfile && sfile->params) {
-    int idx = sfile->params->highlight_file;
+  const FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+  if (sfile && params) {
+    int idx = params->highlight_file;
     int numfiles = filelist_files_ensure(sfile->files);
 
     if ((idx >= 0) && (idx < numfiles)) {
@@ -613,7 +614,7 @@ static bool file_walk_select_selection_set(wmWindow *win,
                                            const bool extend,
                                            const bool fill)
 {
-  FileSelectParams *params = sfile->params;
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   struct FileList *files = sfile->files;
   const int last_sel = params->active_file; /* store old value */
   int active = active_old; /* could use active_old instead, just for readability */
@@ -804,7 +805,7 @@ static bool file_walk_select_do(bContext *C,
 static int file_walk_select_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
 {
   SpaceFile *sfile = (SpaceFile *)CTX_wm_space_data(C);
-  FileSelectParams *params = sfile->params;
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   const int direction = RNA_enum_get(op->ptr, "direction");
   const bool extend = RNA_boolean_get(op->ptr, "extend");
   const bool fill = RNA_boolean_get(op->ptr, "fill");
@@ -853,6 +854,7 @@ static int file_select_all_exec(bContext *C, wmOperator *op)
 {
   ScrArea *area = CTX_wm_area(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   FileSelection sel;
   const int numfiles = filelist_files_ensure(sfile->files);
   int action = RNA_enum_get(op->ptr, "action");
@@ -870,7 +872,7 @@ static int file_select_all_exec(bContext *C, wmOperator *op)
   switch (action) {
     case SEL_SELECT:
     case SEL_INVERT: {
-      check_type = (sfile->params->flag & FILE_DIRSEL_ONLY) ? CHECK_DIRS : CHECK_FILES;
+      check_type = (params->flag & FILE_DIRSEL_ONLY) ? CHECK_DIRS : CHECK_FILES;
       filesel_type = (action == SEL_INVERT) ? FILE_SEL_TOGGLE : FILE_SEL_ADD;
       break;
     }
@@ -888,11 +890,11 @@ static int file_select_all_exec(bContext *C, wmOperator *op)
   filelist_entries_select_index_range_set(
       sfile->files, &sel, filesel_type, FILE_SEL_SELECTED, check_type);
 
-  sfile->params->active_file = -1;
+  params->active_file = -1;
   if (action != SEL_DESELECT) {
     for (int i = 0; i < numfiles; i++) {
       if (filelist_entry_select_index_get(sfile->files, i, check_type)) {
-        sfile->params->active_file = i;
+        params->active_file = i;
         break;
       }
     }
@@ -935,8 +937,8 @@ static int bookmark_select_exec(bContext *C, wmOperator *op)
   PropertyRNA *prop;
 
   if ((prop = RNA_struct_find_property(op->ptr, "dir"))) {
+    FileSelectParams *params = ED_fileselect_get_active_params(sfile);
     char entry[256];
-    FileSelectParams *params = sfile->params;
 
     RNA_property_string_get(op->ptr, prop, entry);
     BLI_strncpy(params->dir, entry, sizeof(params->dir));
@@ -978,7 +980,7 @@ static int bookmark_add_exec(bContext *C, wmOperator *UNUSED(op))
   ScrArea *area = CTX_wm_area(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
   struct FSMenu *fsmenu = ED_fsmenu_get();
-  struct FileSelectParams *params = ED_fileselect_get_params(sfile);
+  struct FileSelectParams *params = ED_fileselect_get_active_params(sfile);
 
   if (params->dir[0] != '\0') {
     char name[FILE_MAX];
@@ -1274,7 +1276,7 @@ int file_highlight_set(SpaceFile *sfile, ARegion *region, int mx, int my)
   }
 
   numfiles = filelist_files_ensure(sfile->files);
-  params = ED_fileselect_get_params(sfile);
+  params = ED_fileselect_get_active_params(sfile);
 
   origfile = params->highlight_file;
 
@@ -1345,20 +1347,21 @@ static int file_column_sort_ui_context_invoke(bContext *C,
 
   if (file_attribute_column_header_is_inside(
           &region->v2d, sfile->layout, event->mval[0], event->mval[1])) {
+    FileSelectParams *params = ED_fileselect_get_active_params(sfile);
     const FileAttributeColumnType column_type = file_attribute_column_type_find_isect(
-        &region->v2d, sfile->params, sfile->layout, event->mval[0]);
+        &region->v2d, params, sfile->layout, event->mval[0]);
 
     if (column_type != COLUMN_NONE) {
       const FileAttributeColumn *column = &sfile->layout->attribute_columns[column_type];
 
       BLI_assert(column->sort_type != FILE_SORT_DEFAULT);
-      if (sfile->params->sort == column->sort_type) {
+      if (params->sort == column->sort_type) {
         /* Already sorting by selected column -> toggle sort invert (three state logic). */
-        sfile->params->flag ^= FILE_SORT_INVERT;
+        params->flag ^= FILE_SORT_INVERT;
       }
       else {
-        sfile->params->sort = column->sort_type;
-        sfile->params->flag &= ~FILE_SORT_INVERT;
+        params->sort = column->sort_type;
+        params->flag &= ~FILE_SORT_INVERT;
       }
 
       WM_event_add_notifier(C, NC_SPACE | ND_SPACE_FILE_PARAMS, NULL);
@@ -1433,10 +1436,11 @@ void FILE_OT_cancel(struct wmOperatorType *ot)
 
 void file_sfile_to_operator_ex(Main *bmain, wmOperator *op, SpaceFile *sfile, char *filepath)
 {
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   PropertyRNA *prop;
 
   /* XXX, not real length */
-  BLI_join_dirfile(filepath, FILE_MAX, sfile->params->dir, sfile->params->file);
+  BLI_join_dirfile(filepath, FILE_MAX, params->dir, params->file);
 
   if ((prop = RNA_struct_find_property(op->ptr, "relative_path"))) {
     if (RNA_property_boolean_get(op->ptr, prop)) {
@@ -1445,10 +1449,10 @@ void file_sfile_to_operator_ex(Main *bmain, wmOperator *op, SpaceFile *sfile, ch
   }
 
   if ((prop = RNA_struct_find_property(op->ptr, "filename"))) {
-    RNA_property_string_set(op->ptr, prop, sfile->params->file);
+    RNA_property_string_set(op->ptr, prop, params->file);
   }
   if ((prop = RNA_struct_find_property(op->ptr, "directory"))) {
-    RNA_property_string_set(op->ptr, prop, sfile->params->dir);
+    RNA_property_string_set(op->ptr, prop, params->dir);
   }
   if ((prop = RNA_struct_find_property(op->ptr, "filepath"))) {
     RNA_property_string_set(op->ptr, prop, filepath);
@@ -1479,7 +1483,7 @@ void file_sfile_to_operator_ex(Main *bmain, wmOperator *op, SpaceFile *sfile, ch
        * files selected */
       if (0 == num_files) {
         RNA_property_collection_add(op->ptr, prop, &itemptr);
-        RNA_string_set(&itemptr, "name", sfile->params->file);
+        RNA_string_set(&itemptr, "name", params->file);
       }
     }
 
@@ -1500,7 +1504,7 @@ void file_sfile_to_operator_ex(Main *bmain, wmOperator *op, SpaceFile *sfile, ch
        * directory selected */
       if (0 == num_dirs) {
         RNA_property_collection_add(op->ptr, prop, &itemptr);
-        RNA_string_set(&itemptr, "name", sfile->params->dir);
+        RNA_string_set(&itemptr, "name", params->dir);
       }
     }
   }
@@ -1514,30 +1518,28 @@ void file_sfile_to_operator(Main *bmain, wmOperator *op, SpaceFile *sfile)
 
 void file_operator_to_sfile(Main *bmain, SpaceFile *sfile, wmOperator *op)
 {
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   PropertyRNA *prop;
 
   /* If neither of the above are set, split the filepath back */
   if ((prop = RNA_struct_find_property(op->ptr, "filepath"))) {
     char filepath[FILE_MAX];
     RNA_property_string_get(op->ptr, prop, filepath);
-    BLI_split_dirfile(filepath,
-                      sfile->params->dir,
-                      sfile->params->file,
-                      sizeof(sfile->params->dir),
-                      sizeof(sfile->params->file));
+    BLI_split_dirfile(
+        filepath, params->dir, params->file, sizeof(params->dir), sizeof(params->file));
   }
   else {
     if ((prop = RNA_struct_find_property(op->ptr, "filename"))) {
-      RNA_property_string_get(op->ptr, prop, sfile->params->file);
+      RNA_property_string_get(op->ptr, prop, params->file);
     }
     if ((prop = RNA_struct_find_property(op->ptr, "directory"))) {
-      RNA_property_string_get(op->ptr, prop, sfile->params->dir);
+      RNA_property_string_get(op->ptr, prop, params->dir);
     }
   }
 
   /* we could check for relative_path property which is used when converting
    * in the other direction but doesn't hurt to do this every time */
-  BLI_path_abs(sfile->params->dir, BKE_main_blendfile_path(bmain));
+  BLI_path_abs(params->dir, BKE_main_blendfile_path(bmain));
 
   /* XXX, files and dirs updates missing, not really so important though */
 }
@@ -1547,21 +1549,19 @@ void file_operator_to_sfile(Main *bmain, SpaceFile *sfile, wmOperator *op)
  */
 void file_sfile_filepath_set(SpaceFile *sfile, const char *filepath)
 {
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   BLI_assert(BLI_exists(filepath));
 
   if (BLI_is_dir(filepath)) {
-    BLI_strncpy(sfile->params->dir, filepath, sizeof(sfile->params->dir));
+    BLI_strncpy(params->dir, filepath, sizeof(params->dir));
   }
   else {
-    if ((sfile->params->flag & FILE_DIRSEL_ONLY) == 0) {
-      BLI_split_dirfile(filepath,
-                        sfile->params->dir,
-                        sfile->params->file,
-                        sizeof(sfile->params->dir),
-                        sizeof(sfile->params->file));
+    if ((params->flag & FILE_DIRSEL_ONLY) == 0) {
+      BLI_split_dirfile(
+          filepath, params->dir, params->file, sizeof(params->dir), sizeof(params->file));
     }
     else {
-      BLI_split_dir_part(filepath, sfile->params->dir, sizeof(sfile->params->dir));
+      BLI_split_dir_part(filepath, params->dir, sizeof(params->dir));
     }
   }
 }
@@ -1605,9 +1605,10 @@ void file_draw_check_cb(bContext *C, void *UNUSED(arg1), void *UNUSED(arg2))
 bool file_draw_check_exists(SpaceFile *sfile)
 {
   if (sfile->op) { /* fails on reload */
-    if (sfile->params && (sfile->params->flag & FILE_CHECK_EXISTING)) {
+    const FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+    if (params && (params->flag & FILE_CHECK_EXISTING)) {
       char filepath[FILE_MAX];
-      BLI_join_dirfile(filepath, sizeof(filepath), sfile->params->dir, sfile->params->file);
+      BLI_join_dirfile(filepath, sizeof(filepath), params->dir, params->file);
       if (BLI_is_file(filepath)) {
         return true;
       }
@@ -1628,21 +1629,22 @@ static int file_exec(bContext *C, wmOperator *exec_op)
   Main *bmain = CTX_data_main(C);
   wmWindowManager *wm = CTX_wm_manager(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
-  struct FileDirEntry *file = filelist_file(sfile->files, sfile->params->active_file);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+  struct FileDirEntry *file = filelist_file(sfile->files, params->active_file);
   char filepath[FILE_MAX];
 
   if (file && file->redirection_path) {
     /* redirection_path is an absolute path that takes precedence
-     * over using sfile->params->dir + sfile->params->file. */
+     * over using params->dir + params->file. */
     BLI_split_dirfile(file->redirection_path,
-                      sfile->params->dir,
-                      sfile->params->file,
-                      sizeof(sfile->params->dir),
-                      sizeof(sfile->params->file));
+                      params->dir,
+                      params->file,
+                      sizeof(params->dir),
+                      sizeof(params->file));
     /* Update relpath with redirected filename as well so that the alternative
-     * combination of sfile->params->dir + relpath remains valid as well. */
+     * combination of params->dir + relpath remains valid as well. */
     MEM_freeN(file->relpath);
-    file->relpath = BLI_strdup(sfile->params->file);
+    file->relpath = BLI_strdup(params->file);
   }
 
   /* directory change */
@@ -1652,12 +1654,12 @@ static int file_exec(bContext *C, wmOperator *exec_op)
     }
 
     if (FILENAME_IS_PARENT(file->relpath)) {
-      BLI_path_parent_dir(sfile->params->dir);
+      BLI_path_parent_dir(params->dir);
     }
     else {
-      BLI_path_normalize(BKE_main_blendfile_path(bmain), sfile->params->dir);
-      BLI_path_append(sfile->params->dir, sizeof(sfile->params->dir) - 1, file->relpath);
-      BLI_path_slash_ensure(sfile->params->dir);
+      BLI_path_normalize(BKE_main_blendfile_path(bmain), params->dir);
+      BLI_path_append(params->dir, sizeof(params->dir) - 1, file->relpath);
+      BLI_path_slash_ensure(params->dir);
     }
     ED_file_change_dir(C);
   }
@@ -1685,10 +1687,10 @@ static int file_exec(bContext *C, wmOperator *exec_op)
 
     file_sfile_to_operator_ex(bmain, op, sfile, filepath);
 
-    if (BLI_exists(sfile->params->dir)) {
+    if (BLI_exists(params->dir)) {
       fsmenu_insert_entry(ED_fsmenu_get(),
                           FS_CATEGORY_RECENT,
-                          sfile->params->dir,
+                          params->dir,
                           NULL,
                           ICON_FILE_FOLDER,
                           FS_INSERT_SAVE | FS_INSERT_FIRST);
@@ -1792,15 +1794,16 @@ static int file_parent_exec(bContext *C, wmOperator *UNUSED(unused))
 {
   Main *bmain = CTX_data_main(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
 
-  if (sfile->params) {
-    if (BLI_path_parent_dir(sfile->params->dir)) {
-      BLI_path_normalize_dir(BKE_main_blendfile_path(bmain), sfile->params->dir);
+  if (params) {
+    if (BLI_path_parent_dir(params->dir)) {
+      BLI_path_normalize_dir(BKE_main_blendfile_path(bmain), params->dir);
       ED_file_change_dir(C);
-      if (sfile->params->recursion_level > 1) {
+      if (params->recursion_level > 1) {
         /* Disable 'dirtree' recursion when going up in tree. */
-        sfile->params->recursion_level = 0;
-        filelist_setrecursion(sfile->files, sfile->params->recursion_level);
+        params->recursion_level = 0;
+        filelist_setrecursion(sfile->files, params->recursion_level);
       }
       WM_event_add_notifier(C, NC_SPACE | ND_SPACE_FILE_LIST, NULL);
     }
@@ -1830,15 +1833,16 @@ void FILE_OT_parent(struct wmOperatorType *ot)
 static int file_previous_exec(bContext *C, wmOperator *UNUSED(op))
 {
   SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
 
-  if (sfile->params) {
+  if (params) {
     if (!sfile->folders_next) {
       sfile->folders_next = folderlist_new();
     }
 
-    folderlist_pushdir(sfile->folders_next, sfile->params->dir);
-    folderlist_popdir(sfile->folders_prev, sfile->params->dir);
-    folderlist_pushdir(sfile->folders_next, sfile->params->dir);
+    folderlist_pushdir(sfile->folders_next, params->dir);
+    folderlist_popdir(sfile->folders_prev, params->dir);
+    folderlist_pushdir(sfile->folders_next, params->dir);
 
     ED_file_change_dir(C);
   }
@@ -1868,16 +1872,17 @@ void FILE_OT_previous(struct wmOperatorType *ot)
 static int file_next_exec(bContext *C, wmOperator *UNUSED(unused))
 {
   SpaceFile *sfile = CTX_wm_space_file(C);
-  if (sfile->params) {
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+  if (params) {
     if (!sfile->folders_next) {
       sfile->folders_next = folderlist_new();
     }
 
-    folderlist_pushdir(sfile->folders_prev, sfile->params->dir);
-    folderlist_popdir(sfile->folders_next, sfile->params->dir);
+    folderlist_pushdir(sfile->folders_prev, params->dir);
+    folderlist_popdir(sfile->folders_next, params->dir);
 
     /* update folders_prev so we can check for it in #folderlist_clear_next() */
-    folderlist_pushdir(sfile->folders_prev, sfile->params->dir);
+    folderlist_pushdir(sfile->folders_prev, params->dir);
 
     ED_file_change_dir(C);
   }
@@ -1923,7 +1928,7 @@ static int file_smoothscroll_invoke(bContext *C, wmOperator *UNUSED(op), const w
   /* Due to async nature of file listing, we may execute this code before `file_refresh()`
    * editing entry is available in our listing,
    * so we also have to handle switching to rename mode here. */
-  FileSelectParams *params = ED_fileselect_get_params(sfile);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   if ((params->rename_flag &
        (FILE_PARAMS_RENAME_PENDING | FILE_PARAMS_RENAME_POSTSCROLL_PENDING)) != 0) {
     file_params_renamefile_activate(sfile, params);
@@ -2175,9 +2180,10 @@ static int file_directory_new_exec(bContext *C, wmOperator *op)
 
   wmWindowManager *wm = CTX_wm_manager(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   const bool do_diropen = RNA_boolean_get(op->ptr, "open");
 
-  if (!sfile->params) {
+  if (!params) {
     BKE_report(op->reports, RPT_WARNING, "No parent directory given");
     return OPERATOR_CANCELLED;
   }
@@ -2193,7 +2199,7 @@ static int file_directory_new_exec(bContext *C, wmOperator *op)
 
   if (generate_name) {
     /* create a new, non-existing folder name */
-    if (!new_folder_path(sfile->params->dir, path, name)) {
+    if (!new_folder_path(params->dir, path, name)) {
       BKE_report(op->reports, RPT_ERROR, "Could not create new folder name");
       return OPERATOR_CANCELLED;
     }
@@ -2226,8 +2232,8 @@ static int file_directory_new_exec(bContext *C, wmOperator *op)
 
   /* If we don't enter the directory directly, remember file to jump into editing. */
   if (do_diropen == false) {
-    BLI_strncpy(sfile->params->renamefile, name, FILE_MAXFILE);
-    sfile->params->rename_flag = FILE_PARAMS_RENAME_PENDING;
+    BLI_strncpy(params->renamefile, name, FILE_MAXFILE);
+    params->rename_flag = FILE_PARAMS_RENAME_PENDING;
   }
 
   /* set timer to smoothly view newly generated file */
@@ -2242,7 +2248,7 @@ static int file_directory_new_exec(bContext *C, wmOperator *op)
   ED_fileselect_clear(wm, CTX_data_scene(C), sfile);
 
   if (do_diropen) {
-    BLI_strncpy(sfile->params->dir, path, sizeof(sfile->params->dir));
+    BLI_strncpy(params->dir, path, sizeof(params->dir));
     ED_file_change_dir(C);
   }
 
@@ -2284,38 +2290,37 @@ static void file_expand_directory(bContext *C)
 {
   Main *bmain = CTX_data_main(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
 
-  if (sfile->params) {
-    if (BLI_path_is_rel(sfile->params->dir)) {
+  if (params) {
+    if (BLI_path_is_rel(params->dir)) {
       /* Use of 'default' folder here is just to avoid an error message on '//' prefix. */
-      BLI_path_abs(sfile->params->dir,
+      BLI_path_abs(params->dir,
                    G.relbase_valid ? BKE_main_blendfile_path(bmain) : BKE_appdir_folder_default());
     }
-    else if (sfile->params->dir[0] == '~') {
-      char tmpstr[sizeof(sfile->params->dir) - 1];
-      BLI_strncpy(tmpstr, sfile->params->dir + 1, sizeof(tmpstr));
-      BLI_join_dirfile(
-          sfile->params->dir, sizeof(sfile->params->dir), BKE_appdir_folder_default(), tmpstr);
+    else if (params->dir[0] == '~') {
+      char tmpstr[sizeof(params->dir) - 1];
+      BLI_strncpy(tmpstr, params->dir + 1, sizeof(tmpstr));
+      BLI_join_dirfile(params->dir, sizeof(params->dir), BKE_appdir_folder_default(), tmpstr);
     }
 
-    else if (sfile->params->dir[0] == '\0')
+    else if (params->dir[0] == '\0')
 #ifndef WIN32
     {
-      sfile->params->dir[0] = '/';
-      sfile->params->dir[1] = '\0';
+      params->dir[0] = '/';
+      params->dir[1] = '\0';
     }
 #else
     {
-      BLI_windows_get_default_root_dir(sfile->params->dir);
+      BLI_windows_get_default_root_dir(params->dir);
     }
     /* change "C:" --> "C:\", T28102. */
-    else if ((isalpha(sfile->params->dir[0]) && (sfile->params->dir[1] == ':')) &&
-             (sfile->params->dir[2] == '\0')) {
-      sfile->params->dir[2] = '\\';
-      sfile->params->dir[3] = '\0';
+    else if ((isalpha(params->dir[0]) && (params->dir[1] == ':')) && (params->dir[2] == '\0')) {
+      params->dir[2] = '\\';
+      params->dir[3] = '\0';
     }
-    else if (BLI_path_is_unc(sfile->params->dir)) {
-      BLI_path_normalize_unc(sfile->params->dir, FILE_MAX_LIBEXTRA);
+    else if (BLI_path_is_unc(params->dir)) {
+      BLI_path_normalize_unc(params->dir, FILE_MAX_LIBEXTRA);
     }
 #endif
   }
@@ -2343,46 +2348,44 @@ void file_directory_enter_handle(bContext *C, void *UNUSED(arg_unused), void *UN
 {
   Main *bmain = CTX_data_main(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
 
-  if (sfile->params) {
-    char old_dir[sizeof(sfile->params->dir)];
+  if (params) {
+    char old_dir[sizeof(params->dir)];
 
-    BLI_strncpy(old_dir, sfile->params->dir, sizeof(old_dir));
+    BLI_strncpy(old_dir, params->dir, sizeof(old_dir));
 
     file_expand_directory(C);
 
     /* special case, user may have pasted a filepath into the directory */
-    if (!filelist_is_dir(sfile->files, sfile->params->dir)) {
+    if (!filelist_is_dir(sfile->files, params->dir)) {
       char tdir[FILE_MAX_LIBEXTRA];
       char *group, *name;
 
-      if (BLI_is_file(sfile->params->dir)) {
-        char path[sizeof(sfile->params->dir)];
-        BLI_strncpy(path, sfile->params->dir, sizeof(path));
-        BLI_split_dirfile(path,
-                          sfile->params->dir,
-                          sfile->params->file,
-                          sizeof(sfile->params->dir),
-                          sizeof(sfile->params->file));
+      if (BLI_is_file(params->dir)) {
+        char path[sizeof(params->dir)];
+        BLI_strncpy(path, params->dir, sizeof(path));
+        BLI_split_dirfile(
+            path, params->dir, params->file, sizeof(params->dir), sizeof(params->file));
       }
-      else if (BLO_library_path_explode(sfile->params->dir, tdir, &group, &name)) {
+      else if (BLO_library_path_explode(params->dir, tdir, &group, &name)) {
         if (group) {
           BLI_path_append(tdir, sizeof(tdir), group);
         }
-        BLI_strncpy(sfile->params->dir, tdir, sizeof(sfile->params->dir));
+        BLI_strncpy(params->dir, tdir, sizeof(params->dir));
         if (name) {
-          BLI_strncpy(sfile->params->file, name, sizeof(sfile->params->file));
+          BLI_strncpy(params->file, name, sizeof(params->file));
         }
         else {
-          sfile->params->file[0] = '\0';
+          params->file[0] = '\0';
         }
       }
     }
 
-    BLI_path_normalize_dir(BKE_main_blendfile_path(bmain), sfile->params->dir);
+    BLI_path_normalize_dir(BKE_main_blendfile_path(bmain), params->dir);
 
-    if (filelist_is_dir(sfile->files, sfile->params->dir)) {
-      if (!STREQ(sfile->params->dir, old_dir)) { /* Avoids flickering when nothing's changed. */
+    if (filelist_is_dir(sfile->files, params->dir)) {
+      if (!STREQ(params->dir, old_dir)) { /* Avoids flickering when nothing's changed. */
         /* if directory exists, enter it immediately */
         ED_file_change_dir(C);
       }
@@ -2392,10 +2395,10 @@ void file_directory_enter_handle(bContext *C, void *UNUSED(arg_unused), void *UN
       /* UI_textbutton_activate_but(C, but); */
     }
 #if defined(WIN32)
-    else if (!can_create_dir(sfile->params->dir)) {
+    else if (!can_create_dir(params->dir)) {
       const char *lastdir = folderlist_peeklastdir(sfile->folders_prev);
       if (lastdir) {
-        BLI_strncpy(sfile->params->dir, lastdir, sizeof(sfile->params->dir));
+        BLI_strncpy(params->dir, lastdir, sizeof(params->dir));
       }
     }
 #endif
@@ -2405,21 +2408,21 @@ void file_directory_enter_handle(bContext *C, void *UNUSED(arg_unused), void *UN
 
       /* If we are 'inside' a blend library, we cannot do anything... */
       if (lastdir && BLO_library_path_explode(lastdir, tdir, NULL, NULL)) {
-        BLI_strncpy(sfile->params->dir, lastdir, sizeof(sfile->params->dir));
+        BLI_strncpy(params->dir, lastdir, sizeof(params->dir));
       }
       else {
         /* if not, ask to create it and enter if confirmed */
         wmOperatorType *ot = WM_operatortype_find("FILE_OT_directory_new", false);
         PointerRNA ptr;
         WM_operator_properties_create_ptr(&ptr, ot);
-        RNA_string_set(&ptr, "directory", sfile->params->dir);
+        RNA_string_set(&ptr, "directory", params->dir);
         RNA_boolean_set(&ptr, "open", true);
         /* Enable confirmation prompt, else it's too easy
          * to accidentally create new directories. */
         RNA_boolean_set(&ptr, "confirm", true);
 
         if (lastdir) {
-          BLI_strncpy(sfile->params->dir, lastdir, sizeof(sfile->params->dir));
+          BLI_strncpy(params->dir, lastdir, sizeof(params->dir));
         }
 
         WM_operator_name_call_ptr(C, ot, WM_OP_INVOKE_DEFAULT, &ptr);
@@ -2435,39 +2438,39 @@ void file_filename_enter_handle(bContext *C, void *UNUSED(arg_unused), void *arg
 {
   Main *bmain = CTX_data_main(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   uiBut *but = arg_but;
   char matched_file[FILE_MAX];
-  char filepath[sizeof(sfile->params->dir)];
 
-  if (sfile->params) {
+  if (params) {
+    char filepath[sizeof(params->dir)];
     int matches;
     matched_file[0] = '\0';
     filepath[0] = '\0';
 
     file_expand_directory(C);
 
-    matches = file_select_match(sfile, sfile->params->file, matched_file);
+    matches = file_select_match(sfile, params->file, matched_file);
 
     /* *After* file_select_match! */
-    BLI_filename_make_safe(sfile->params->file);
+    BLI_filename_make_safe(params->file);
 
     if (matches) {
       /* replace the pattern (or filename that the user typed in,
        * with the first selected file of the match */
-      BLI_strncpy(sfile->params->file, matched_file, sizeof(sfile->params->file));
+      BLI_strncpy(params->file, matched_file, sizeof(params->file));
 
       WM_event_add_notifier(C, NC_SPACE | ND_SPACE_FILE_PARAMS, NULL);
     }
 
     if (matches == 1) {
-      BLI_join_dirfile(
-          filepath, sizeof(sfile->params->dir), sfile->params->dir, sfile->params->file);
+      BLI_join_dirfile(filepath, sizeof(params->dir), params->dir, params->file);
 
       /* if directory, open it and empty filename field */
       if (filelist_is_dir(sfile->files, filepath)) {
         BLI_path_normalize_dir(BKE_main_blendfile_path(bmain), filepath);
-        BLI_strncpy(sfile->params->dir, filepath, sizeof(sfile->params->dir));
-        sfile->params->file[0] = '\0';
+        BLI_strncpy(params->dir, filepath, sizeof(params->dir));
+        params->file[0] = '\0';
         ED_file_change_dir(C);
         UI_textbutton_activate_but(C, but);
         WM_event_add_notifier(C, NC_SPACE | ND_SPACE_FILE_PARAMS, NULL);
@@ -2489,9 +2492,10 @@ static int file_hidedot_exec(bContext *C, wmOperator *UNUSED(unused))
 {
   wmWindowManager *wm = CTX_wm_manager(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
 
-  if (sfile->params) {
-    sfile->params->flag ^= FILE_HIDE_DOT;
+  if (params) {
+    params->flag ^= FILE_HIDE_DOT;
     ED_fileselect_clear(wm, CTX_data_scene(C), sfile);
     WM_event_add_notifier(C, NC_SPACE | ND_SPACE_FILE_LIST, NULL);
   }
@@ -2525,7 +2529,8 @@ static bool file_filenum_poll(bContext *C)
     return false;
   }
 
-  return sfile->params && (sfile->params->flag & FILE_CHECK_EXISTING);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+  return params && (params->flag & FILE_CHECK_EXISTING);
 }
 
 /**
@@ -2563,11 +2568,12 @@ static void filenum_newname(char *name, size_t name_size, int add)
 static int file_filenum_exec(bContext *C, wmOperator *op)
 {
   SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   ScrArea *area = CTX_wm_area(C);
 
   int inc = RNA_int_get(op->ptr, "increment");
-  if (sfile->params && (inc != 0)) {
-    filenum_newname(sfile->params->file, sizeof(sfile->params->file), inc);
+  if (params && (inc != 0)) {
+    filenum_newname(params->file, sizeof(params->file), inc);
     ED_area_tag_redraw(area);
     file_draw_check(C);
     // WM_event_add_notifier(C, NC_WINDOW, NULL);
@@ -2606,12 +2612,14 @@ static void file_rename_state_activate(SpaceFile *sfile, int file_idx, bool requ
 
     if ((require_selected == false) ||
         (filelist_entry_select_get(sfile->files, file, CHECK_ALL) & FILE_SEL_SELECTED)) {
+      FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+
       filelist_entry_select_index_set(
           sfile->files, file_idx, FILE_SEL_ADD, FILE_SEL_EDITING, CHECK_ALL);
-      BLI_strncpy(sfile->params->renamefile, file->relpath, FILE_MAXFILE);
+      BLI_strncpy(params->renamefile, file->relpath, FILE_MAXFILE);
       /* We can skip the pending state,
        * as we can directly set FILE_SEL_EDITING on the expected entry here. */
-      sfile->params->rename_flag = FILE_PARAMS_RENAME_ACTIVE;
+      params->rename_flag = FILE_PARAMS_RENAME_ACTIVE;
     }
   }
 }
@@ -2620,9 +2628,10 @@ static int file_rename_invoke(bContext *C, wmOperator *UNUSED(op), const wmEvent
 {
   ScrArea *area = CTX_wm_area(C);
   SpaceFile *sfile = (SpaceFile *)CTX_wm_space_data(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
 
-  if (sfile->params) {
-    file_rename_state_activate(sfile, sfile->params->active_file, true);
+  if (params) {
+    file_rename_state_activate(sfile, params->active_file, true);
     ED_area_tag_redraw(area);
   }
 
@@ -2633,9 +2642,10 @@ static int file_rename_exec(bContext *C, wmOperator *UNUSED(op))
 {
   ScrArea *area = CTX_wm_area(C);
   SpaceFile *sfile = (SpaceFile *)CTX_wm_space_data(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
 
-  if (sfile->params) {
-    file_rename_state_activate(sfile, sfile->params->highlight_file, false);
+  if (params) {
+    file_rename_state_activate(sfile, params->highlight_file, false);
     ED_area_tag_redraw(area);
   }
 
@@ -2665,8 +2675,9 @@ static bool file_delete_poll(bContext *C)
 {
   bool poll = ED_operator_file_active(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
 
-  if (sfile && sfile->params) {
+  if (sfile && params) {
     char dir[FILE_MAX_LIBEXTRA];
     int numfiles = filelist_files_ensure(sfile->files);
     int i;
@@ -2695,6 +2706,7 @@ static int file_delete_exec(bContext *C, wmOperator *op)
 {
   wmWindowManager *wm = CTX_wm_manager(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   int numfiles = filelist_files_ensure(sfile->files);
 
   const char *error_message = NULL;
@@ -2704,7 +2716,7 @@ static int file_delete_exec(bContext *C, wmOperator *op)
     if (filelist_entry_select_index_get(sfile->files, i, CHECK_ALL)) {
       FileDirEntry *file = filelist_file(sfile->files, i);
       char str[FILE_MAX];
-      BLI_join_dirfile(str, sizeof(str), sfile->params->dir, file->relpath);
+      BLI_join_dirfile(str, sizeof(str), params->dir, file->relpath);
       if (BLI_delete_soft(str, &error_message) != 0 || BLI_exists(str)) {
         report_error = true;
       }
@@ -2752,11 +2764,12 @@ static int file_start_filter_exec(bContext *C, wmOperator *UNUSED(op))
 {
   ScrArea *area = CTX_wm_area(C);
   ARegion *region = BKE_area_find_region_type(area, RGN_TYPE_UI);
-  SpaceFile *sf = CTX_wm_space_file(C);
+  SpaceFile *sfile = CTX_wm_space_file(C);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
 
   ARegion *region_ctx = CTX_wm_region(C);
   CTX_wm_region_set(C, region);
-  UI_textbutton_activate_rna(C, region, sf->params, "filter_search");
+  UI_textbutton_activate_rna(C, region, params, "filter_search");
   CTX_wm_region_set(C, region_ctx);
 
   return OPERATOR_FINISHED;
diff --git a/source/blender/editors/space_file/file_panels.c b/source/blender/editors/space_file/file_panels.c
index 22d206c0a70..afa85d183d8 100644
--- a/source/blender/editors/space_file/file_panels.c
+++ b/source/blender/editors/space_file/file_panels.c
@@ -132,7 +132,7 @@ static void file_panel_execution_buttons_draw(const bContext *C, Panel *panel)
 {
   bScreen *screen = CTX_wm_screen(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
-  FileSelectParams *params = ED_fileselect_get_params(sfile);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   uiBlock *block = uiLayoutGetBlock(panel->layout);
   uiBut *but;
   uiLayout *row;
diff --git a/source/blender/editors/space_file/filelist.c b/source/blender/editors/space_file/filelist.c
index b6d016aca7c..58887ae745b 100644
--- a/source/blender/editors/space_file/filelist.c
+++ b/source/blender/editors/space_file/filelist.c
@@ -149,6 +149,7 @@ const char *folderlist_peeklastdir(ListBase *folderlist)
 
 int folderlist_clear_next(struct SpaceFile *sfile)
 {
+  const FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   struct FolderList *folder;
 
   /* if there is no folder_next there is nothing we can clear */
@@ -159,7 +160,7 @@ int folderlist_clear_next(struct SpaceFile *sfile)
   /* if previous_folder, next_folder or refresh_folder operators are executed
    * it doesn't clear folder_next */
   folder = sfile->folders_prev->last;
-  if ((!folder) || (BLI_path_cmp(folder->foldername, sfile->params->dir) == 0)) {
+  if ((!folder) || (BLI_path_cmp(folder->foldername, params->dir) == 0)) {
     return 0;
   }
 
diff --git a/source/blender/editors/space_file/filesel.c b/source/blender/editors/space_file/filesel.c
index 15c6972c5f5..ffa44083473 100644
--- a/source/blender/editors/space_file/filesel.c
+++ b/source/blender/editors/space_file/filesel.c
@@ -77,18 +77,20 @@
 
 #define VERTLIST_MAJORCOLUMN_WIDTH (25 * UI_UNIT_X)
 
-FileSelectParams *ED_fileselect_get_params(struct SpaceFile *sfile)
+FileSelectParams *ED_fileselect_get_active_params(const SpaceFile *sfile)
 {
-  if (!sfile->params) {
-    ED_fileselect_set_params(sfile);
+  if (!sfile) {
+    /* Sometimes called in poll before space type was checked. */
+    return NULL;
   }
+
   return sfile->params;
 }
 
 /**
  * \note RNA_struct_property_is_set_ex is used here because we want
  *       the previously used settings to be used here rather than overriding them */
-short ED_fileselect_set_params(SpaceFile *sfile)
+static void fileselect_ensure_file_params(SpaceFile *sfile)
 {
   FileSelectParams *params;
   wmOperator *op = sfile->op;
@@ -136,20 +138,17 @@ short ED_fileselect_set_params(SpaceFile *sfile)
       RNA_string_get(op->ptr, "filepath", name);
       if (params->type == FILE_LOADLIB) {
         BLI_strncpy(params->dir, name, sizeof(params->dir));
-        sfile->params->file[0] = '\0';
+        params->file[0] = '\0';
       }
       else {
-        BLI_split_dirfile(name,
-                          sfile->params->dir,
-                          sfile->params->file,
-                          sizeof(sfile->params->dir),
-                          sizeof(sfile->params->file));
+        BLI_split_dirfile(
+            name, params->dir, params->file, sizeof(params->dir), sizeof(params->file));
       }
     }
     else {
       if (is_directory && RNA_struct_property_is_set_ex(op->ptr, "directory", false)) {
         RNA_string_get(op->ptr, "directory", params->dir);
-        sfile->params->file[0] = '\0';
+        params->file[0] = '\0';
       }
 
       if (is_filename && RNA_struct_property_is_set_ex(op->ptr, "filename", false)) {
@@ -306,26 +305,32 @@ short ED_fileselect_set_params(SpaceFile *sfile)
     sfile->folders_prev = folderlist_new();
   }
 
-  if (!sfile->params->dir[0]) {
+  if (!params->dir[0]) {
     if (blendfile_path[0] != '\0') {
-      BLI_split_dir_part(blendfile_path, sfile->params->dir, sizeof(sfile->params->dir));
+      BLI_split_dir_part(blendfile_path, params->dir, sizeof(params->dir));
     }
     else {
       const char *doc_path = BKE_appdir_folder_default();
       if (doc_path) {
-        BLI_strncpy(sfile->params->dir, doc_path, sizeof(sfile->params->dir));
+        BLI_strncpy(params->dir, doc_path, sizeof(params->dir));
       }
     }
   }
 
-  folderlist_pushdir(sfile->folders_prev, sfile->params->dir);
+  folderlist_pushdir(sfile->folders_prev, params->dir);
 
   /* Switching thumbnails needs to recalc layout T28809. */
   if (sfile->layout) {
     sfile->layout->dirty = true;
   }
+}
 
-  return 1;
+FileSelectParams *ED_fileselect_ensure_active_params(SpaceFile *sfile)
+{
+  if (!sfile->params) {
+    fileselect_ensure_file_params(sfile);
+  }
+  return sfile->params;
 }
 
 /* The subset of FileSelectParams.flag items we store into preferences. Note that FILE_SORT_ALPHA
@@ -364,28 +369,26 @@ void ED_fileselect_set_params_from_userdef(SpaceFile *sfile)
   wmOperator *op = sfile->op;
   UserDef_FileSpaceData *sfile_udata = &U.file_space_data;
 
-  ED_fileselect_set_params(sfile);
-
+  FileSelectParams *params = ED_fileselect_ensure_active_params(sfile);
   if (!op) {
     return;
   }
 
-  sfile->params->thumbnail_size = sfile_udata->thumbnail_size;
-  sfile->params->details_flags = sfile_udata->details_flags;
-  sfile->params->filter_id = sfile_udata->filter_id;
+  params->thumbnail_size = sfile_udata->thumbnail_size;
+  params->details_flags = sfile_udata->details_flags;
+  params->filter_id = sfile_udata->filter_id;
 
   /* Combine flags we take from params with the flags we take from userdef. */
-  sfile->params->flag = (sfile->params->flag & ~PARAMS_FLAGS_REMEMBERED) |
-                        (sfile_udata->flag & PARAMS_FLAGS_REMEMBERED);
+  params->flag = (params->flag & ~PARAMS_FLAGS_REMEMBERED) |
+                 (sfile_udata->flag & PARAMS_FLAGS_REMEMBERED);
 
   if (file_select_use_default_display_type(sfile)) {
-    sfile->params->display = sfile_udata->display_type;
+    params->display = sfile_udata->display_type;
   }
   if (file_select_use_default_sort_type(sfile)) {
-    sfile->params->sort = sfile_udata->sort_type;
+    params->sort = sfile_udata->sort_type;
     /* For the default sorting, also take invert flag from userdef. */
-    sfile->params->flag = (sfile->params->flag & ~FILE_SORT_INVERT) |
-                          (sfile_udata->flag & FILE_SORT_INVERT);
+    params->flag = (params->flag & ~FILE_SORT_INVERT) | (sfile_udata->flag & FILE_SORT_INVERT);
   }
 }
 
@@ -400,25 +403,26 @@ void ED_fileselect_params_to_userdef(SpaceFile *sfile,
                                      const int temp_win_size[2],
                                      const bool is_maximized)
 {
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   UserDef_FileSpaceData *sfile_udata_new = &U.file_space_data;
   UserDef_FileSpaceData sfile_udata_old = U.file_space_data;
 
-  sfile_udata_new->thumbnail_size = sfile->params->thumbnail_size;
-  sfile_udata_new->details_flags = sfile->params->details_flags;
-  sfile_udata_new->flag = sfile->params->flag & PARAMS_FLAGS_REMEMBERED;
-  sfile_udata_new->filter_id = sfile->params->filter_id;
+  sfile_udata_new->thumbnail_size = params->thumbnail_size;
+  sfile_udata_new->details_flags = params->details_flags;
+  sfile_udata_new->flag = params->flag & PARAMS_FLAGS_REMEMBERED;
+  sfile_udata_new->filter_id = params->filter_id;
 
   /* In some rare cases, operators ask for a specific display or sort type (e.g. chronological
    * sorting for "Recover Auto Save"). So the settings are optimized for a specific operation.
    * Don't let that change the userdef memory for more general cases. */
   if (file_select_use_default_display_type(sfile)) {
-    sfile_udata_new->display_type = sfile->params->display;
+    sfile_udata_new->display_type = params->display;
   }
   if (file_select_use_default_sort_type(sfile)) {
-    sfile_udata_new->sort_type = sfile->params->sort;
+    sfile_udata_new->sort_type = params->sort;
     /* In this case also remember the invert flag. */
     sfile_udata_new->flag = (sfile_udata_new->flag & ~FILE_SORT_INVERT) |
-                            (sfile->params->flag & FILE_SORT_INVERT);
+                            (params->flag & FILE_SORT_INVERT);
   }
 
   if (temp_win_size && !is_maximized) {
@@ -434,10 +438,11 @@ void ED_fileselect_params_to_userdef(SpaceFile *sfile,
 
 void ED_fileselect_reset_params(SpaceFile *sfile)
 {
-  sfile->params->type = FILE_UNIX;
-  sfile->params->flag = 0;
-  sfile->params->title[0] = '\0';
-  sfile->params->active_file = -1;
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+  params->type = FILE_UNIX;
+  params->flag = 0;
+  params->title[0] = '\0';
+  params->active_file = -1;
 }
 
 /**
@@ -447,7 +452,8 @@ void fileselect_file_set(SpaceFile *sfile, const int index)
 {
   const struct FileDirEntry *file = filelist_file(sfile->files, index);
   if (file && file->relpath && file->relpath[0] && !(file->typeflag & FILE_TYPE_DIR)) {
-    BLI_strncpy(sfile->params->file, file->relpath, FILE_MAXFILE);
+    FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+    BLI_strncpy(params->file, file->relpath, FILE_MAXFILE);
   }
 }
 
@@ -759,7 +765,7 @@ static void file_attribute_columns_init(const FileSelectParams *params, FileLayo
 
 void ED_fileselect_init_layout(struct SpaceFile *sfile, ARegion *region)
 {
-  FileSelectParams *params = ED_fileselect_get_params(sfile);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   FileLayout *layout = NULL;
   View2D *v2d = &region->v2d;
   int numfiles;
@@ -873,7 +879,8 @@ void ED_file_change_dir_ex(bContext *C, bScreen *screen, ScrArea *area)
     return;
   }
   SpaceFile *sfile = area->spacedata.first;
-  if (sfile->params) {
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+  if (params) {
     wmWindowManager *wm = CTX_wm_manager(C);
     Scene *scene = WM_windows_scene_get_from_screen(wm, screen);
     if (LIKELY(scene != NULL)) {
@@ -882,20 +889,20 @@ void ED_file_change_dir_ex(bContext *C, bScreen *screen, ScrArea *area)
 
     /* Clear search string, it is very rare to want to keep that filter while changing dir,
      * and usually very annoying to keep it actually! */
-    sfile->params->filter_search[0] = '\0';
-    sfile->params->active_file = -1;
+    params->filter_search[0] = '\0';
+    params->active_file = -1;
 
-    if (!filelist_is_dir(sfile->files, sfile->params->dir)) {
-      BLI_strncpy(sfile->params->dir, filelist_dir(sfile->files), sizeof(sfile->params->dir));
+    if (!filelist_is_dir(sfile->files, params->dir)) {
+      BLI_strncpy(params->dir, filelist_dir(sfile->files), sizeof(params->dir));
       /* could return but just refresh the current dir */
     }
-    filelist_setdir(sfile->files, sfile->params->dir);
+    filelist_setdir(sfile->files, params->dir);
 
     if (folderlist_clear_next(sfile)) {
       folderlist_free(sfile->folders_next);
     }
 
-    folderlist_pushdir(sfile->folders_prev, sfile->params->dir);
+    folderlist_pushdir(sfile->folders_prev, params->dir);
 
     file_draw_check_ex(C, area);
   }
@@ -1010,7 +1017,8 @@ void ED_fileselect_clear(wmWindowManager *wm, Scene *owner_scene, SpaceFile *sfi
     filelist_clear(sfile->files);
   }
 
-  sfile->params->highlight_file = -1;
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+  params->highlight_file = -1;
   WM_main_add_notifier(NC_SPACE | ND_SPACE_FILE_LIST, NULL);
 }
 
diff --git a/source/blender/editors/space_file/space_file.c b/source/blender/editors/space_file/space_file.c
index 6ffe553e076..c72ca58abba 100644
--- a/source/blender/editors/space_file/space_file.c
+++ b/source/blender/editors/space_file/space_file.c
@@ -270,7 +270,7 @@ static void file_refresh(const bContext *C, ScrArea *area)
   wmWindowManager *wm = CTX_wm_manager(C);
   wmWindow *win = CTX_wm_window(C);
   SpaceFile *sfile = CTX_wm_space_file(C);
-  FileSelectParams *params = ED_fileselect_get_params(sfile);
+  FileSelectParams *params = ED_fileselect_ensure_active_params(sfile);
   struct FSMenu *fsmenu = ED_fsmenu_get();
 
   if (!sfile->folders_prev) {
@@ -413,7 +413,7 @@ static void file_main_region_message_subscribe(const struct bContext *UNUSED(C),
                                                struct wmMsgBus *mbus)
 {
   SpaceFile *sfile = area->spacedata.first;
-  FileSelectParams *params = ED_fileselect_get_params(sfile);
+  FileSelectParams *params = ED_fileselect_ensure_active_params(sfile);
   /* This is a bit odd that a region owns the subscriber for an area,
    * keep for now since all subscribers for WM are regions.
    * May be worth re-visiting later. */
@@ -446,7 +446,7 @@ static void file_main_region_draw(const bContext *C, ARegion *region)
 {
   /* draw entirely, view changes should be handled here */
   SpaceFile *sfile = CTX_wm_space_file(C);
-  FileSelectParams *params = ED_fileselect_get_params(sfile);
+  FileSelectParams *params = ED_fileselect_ensure_active_params(sfile);
 
   View2D *v2d = &region->v2d;