Add support for loading preference struct

Previously it would always load into 'U' global.
Needed for loading & merging template preferences.

source/blender/blenkernel/BKE_blender.h

@@ -48,9 +48,10 @@ void BKE_blender_version_string(
         char *version_str, size_t maxncpy,
         short version, short subversion, bool v_prefix, bool include_subversion);
 
-void BKE_blender_userdef_free(struct UserDef *userdef);
+void BKE_blender_userdef_set_data(struct UserDef *userdef);
+void BKE_blender_userdef_free_data(struct UserDef *userdef);
 void BKE_blender_userdef_refresh(void);
-	
+
 /* set this callback when a UI is running */
 void BKE_blender_callback_test_break_set(void (*func)(void));
 int  BKE_blender_test_break(void);

source/blender/blenkernel/BKE_blendfile.h

@@ -33,6 +33,7 @@ struct ID;
 struct Main;
 struct MemFile;
 struct ReportList;
+struct UserDef;
 
 enum {
 	BKE_BLENDFILE_READ_FAIL             = 0, /* no load */
@@ -50,8 +51,8 @@ bool BKE_blendfile_read_from_memfile(
         struct bContext *C, struct MemFile *memfile,
         struct ReportList *reports, int skip_flag);
 
-int BKE_blendfile_read_userdef(const char *filepath, struct ReportList *reports);
-int BKE_blendfile_write_userdef(const char *filepath, struct ReportList *reports);
+struct UserDef *BKE_blendfile_userdef_read(const char *filepath, struct ReportList *reports);
+int             BKE_blendfile_userdef_write(const char *filepath, struct ReportList *reports);
 
 
 /* partial blend file writing */

source/blender/blenkernel/intern/blender.c

@@ -150,11 +150,18 @@ static void keymap_item_free(wmKeyMapItem *kmi)
 		MEM_freeN(kmi->ptr);
 }
 
+void BKE_blender_userdef_set_data(UserDef *userdef)
+{
+	/* only here free userdef themes... */
+	BKE_blender_userdef_free_data(&U);
+	U = *userdef;
+}
+
 /**
  * When loading a new userdef from file,
  * or when exiting Blender.
  */
-void BKE_blender_userdef_free(UserDef *userdef)
+void BKE_blender_userdef_free_data(UserDef *userdef)
 {
 #define U _invalid_access_ /* ensure no accidental global access */
 #ifdef U  /* quiet warning */

source/blender/blenkernel/intern/blendfile.c

@@ -227,7 +227,7 @@ static void setup_app_data(
 	if (bfd->user) {
 
 		/* only here free userdef themes... */
-		BKE_blender_userdef_free(&U);
+		BKE_blender_userdef_free_data(&U);
 
 		U = *bfd->user;
 
@@ -425,31 +425,25 @@ bool BKE_blendfile_read_from_memfile(
 }
 
 /* only read the userdef from a .blend */
-int BKE_blendfile_read_userdef(const char *filepath, ReportList *reports)
+UserDef *BKE_blendfile_userdef_read(const char *filepath, ReportList *reports)
 {
 	BlendFileData *bfd;
-	int retval = BKE_BLENDFILE_READ_FAIL;
+	UserDef *userdef = NULL;
 
 	bfd = BLO_read_from_file(filepath, reports, BLO_READ_SKIP_NONE);
 	if (bfd) {
 		if (bfd->user) {
-			retval = BKE_BLENDFILE_READ_OK_USERPREFS;
-
-			/* only here free userdef themes... */
-			BKE_blender_userdef_free(&U);
-
-			U = *bfd->user;
-			MEM_freeN(bfd->user);
+			userdef = bfd->user;
 		}
 		BKE_main_free(bfd->main);
 		MEM_freeN(bfd);
 	}
 
-	return retval;
+	return userdef;
 }
 
 /* only write the userdef in a .blend */
-int BKE_blendfile_write_userdef(const char *filepath, ReportList *reports)
+int BKE_blendfile_userdef_write(const char *filepath, ReportList *reports)
 {
 	Main *mainb = MEM_callocN(sizeof(Main), "empty main");
 	int retval = 0;

source/blender/windowmanager/intern/wm_files.c

@@ -697,8 +697,11 @@ int wm_homefile_read(
 	
 	/* load preferences before startup.blend */
 	if (!from_memory && BLI_exists(filepath_userdef)) {
-		int done = BKE_blendfile_read_userdef(filepath_userdef, NULL);
-		if (done != BKE_BLENDFILE_READ_FAIL) {
+		UserDef *userdef = BKE_blendfile_userdef_read(filepath_userdef, NULL);
+		if (userdef != NULL) {
+			BKE_blender_userdef_set_data(userdef);
+			MEM_freeN(userdef);
+
 			read_userdef_from_memory = false;
 			skip_flags |= BLO_READ_SKIP_USERDEF;
 			printf("Read prefs: %s\n", filepath_userdef);
@@ -1365,7 +1368,7 @@ static int wm_userpref_write_exec(bContext *C, wmOperator *op)
 	BLI_make_file_string("/", filepath, BKE_appdir_folder_id_create(BLENDER_USER_CONFIG, NULL), BLENDER_USERPREF_FILE);
 	printf("trying to save userpref at %s ", filepath);
 
-	if (BKE_blendfile_write_userdef(filepath, op->reports) == 0) {
+	if (BKE_blendfile_userdef_write(filepath, op->reports) == 0) {
 		printf("fail\n");
 		return OPERATOR_CANCELLED;
 	}

source/blender/windowmanager/intern/wm_init_exit.c

@@ -572,7 +572,7 @@ void WM_exit_ext(bContext *C, const bool do_python)
 	ED_file_exit(); /* for fsmenu */
 
 	UI_exit();
-	BKE_blender_userdef_free(&U);
+	BKE_blender_userdef_free_data(&U);
 
 	RNA_exit(); /* should be after BPY_python_end so struct python slots are cleared */