fix(textarea): support Arabic letter connections

fixes #1888

CHANGELOG.md

@@ -11,6 +11,7 @@
 - fix(btnmatrix) handle arabic texts in button matrices
 - fix(indev) disabled object shouldn't absorb clicks but let the parent to be clicked
 - fix(arabic) support processing again already processed texts with _lv_txt_ap_proc
+- fix(textarea) support Arabic letter connections
 
 ## v7.7.2 (Planned to 17.11.2020)
 ### Bugfixes

src/lv_widgets/lv_label.c

@@ -185,11 +185,8 @@ void lv_label_set_text(lv_obj_t * label, const char * text)
 
     lv_label_ext_t * ext = lv_obj_get_ext_attr(label);
 
-    /*If text is NULL then refresh */
-    if(text == NULL) {
-        lv_label_refr_text(label);
-        return;
-    }
+    /*If text is NULL then just refresh with the current text */
+    if(text == NULL) text = ext->text;
 
     LV_ASSERT_STR(text);
 
@@ -962,7 +959,7 @@ void lv_label_ins_text(lv_obj_t * label, uint32_t pos, const char * txt)
 #else
     _lv_txt_ins(ext->text, pos, txt);
 #endif
-    lv_label_refr_text(label);
+    lv_label_set_text(label, NULL);
 }
 
 /**