Text3d: assert for <0 len text

also add operator to test blacklist

source/blender/blenkernel/intern/font.c

@@ -488,6 +488,7 @@ int BKE_vfont_select_get(Object *ob, int *r_start, int *r_end)
 	
 	if ((ob->type != OB_FONT) || (ef == NULL)) return 0;
 
+	BLI_assert(ef->len >= 0);
 	BLI_assert(ef->selstart >= 0 && ef->selstart <= ef->len + 1);
 	BLI_assert(ef->selend   >= 0 && ef->selend   <= ef->len);
 	BLI_assert(ef->pos      >= 0 && ef->pos      <= ef->len);

source/blender/editors/curve/editfont.c

@@ -248,6 +248,8 @@ static void text_update_edited(bContext *C, Object *obedit, int mode)
 	Curve *cu = obedit->data;
 	EditFont *ef = cu->editfont;
 
+	BLI_assert(ef->len >= 0);
+
 	/* run update first since it can move the cursor */
 	if (mode == FO_EDIT) {
 		/* re-tesselllate */
@@ -1583,6 +1585,7 @@ void make_editText(Object *obedit)
 	len_wchar = BLI_strncpy_wchar_from_utf8(ef->textbuf, cu->str, MAXTEXT + 4);
 	BLI_assert(len_wchar == cu->len_wchar);
 	ef->len = len_wchar;
+	BLI_assert(ef->len >= 0);
 
 	memcpy(ef->textbufinfo, cu->strinfo, ef->len * sizeof(CharInfo));
 

tests/python/bl_run_operators.py

@@ -66,6 +66,7 @@ op_blacklist = (
     "wm.doc_edit",
     "wm.doc_view_manual",
     "wm.path_open",
+    "wm.copy_prev_settings",
     "wm.theme_install",
     "wm.context_*",
     "wm.properties_add",