Fixing #2350

Previously, we ignored widget field flags changes for all button types (in an effort to fight potential user errors). This however prevented "legal" flags modifications for these widget types.

This fix now simply relies on correct valus provided by the user and puts the provided field flags value to the PDF.

Also make sure we are keeping the right widget type. When setting field flags, we must ensure to re-check the field type and set those flag bits that PDF uses to differentiate between the three button types and the two choice type.

Also removed unnecessary use of fitz.PDF_WIDGET_TYPE_COMBOBOX flag in
tests/test_widgets.py:test_combobox().

fitz/helper-fields.i

@@ -730,18 +730,18 @@ void JM_set_widget_properties(fz_context *ctx, pdf_annot *annot, PyObject *Widge
     pdf_dict_del(ctx, annot_obj, PDF_NAME(RC)); /* not supported by MuPDF */
 
     // field flags ------------------------------------------------------------
-    int field_flags = 0, Ff = 0;
-    if (field_type != PDF_WIDGET_TYPE_CHECKBOX &&
-        field_type != PDF_WIDGET_TYPE_BUTTON &&
-        field_type != PDF_WIDGET_TYPE_RADIOBUTTON) {
-        value = GETATTR("field_flags");
-        field_flags = (int) PyInt_AsLong(value);
-        if (!PyErr_Occurred()) {
-            Ff = pdf_field_flags(ctx, annot_obj);
-            Ff |= field_flags;
+    value = GETATTR("field_flags");
+    int field_flags = (int) PyInt_AsLong(value);
+    Py_XDECREF(value);
+    if (!PyErr_Occurred()) {
+        if (field_type == PDF_WIDGET_TYPE_COMBOBOX) {
+            field_flags |= PDF_CH_FIELD_IS_COMBO;
+        } else if (field_type == PDF_WIDGET_TYPE_RADIOBUTTON) {
+            field_flags |= PDF_BTN_FIELD_IS_RADIO;
+        } else if (field_type == PDF_WIDGET_TYPE_BUTTON) {
+            field_flags |= PDF_BTN_FIELD_IS_PUSHBUTTON;
         }
-        Py_XDECREF(value);
-        pdf_dict_put_int(ctx, annot_obj, PDF_NAME(Ff), Ff);
+        pdf_dict_put_int(ctx, annot_obj, PDF_NAME(Ff), field_flags);
     }
 
     // button caption ---------------------------------------------------------

tests/test_widgets.py

@@ -112,7 +112,6 @@ def test_combobox():
     widget.field_flags = (
         fitz.PDF_CH_FIELD_IS_COMMIT_ON_SEL_CHANGE
         | fitz.PDF_CH_FIELD_IS_EDIT
-        | fitz.PDF_WIDGET_TYPE_COMBOBOX
     )
     widget.fill_color = gold
     widget.choice_values = (