Assert if wxListCtrl::EditLabel() is used without wxLC_EDIT_LABELS

Since wxListCtrl under wxMSW cannot edit labels without the presence of
this flag, and an assertion failure triggered if the flag is missing to
it and also all the other ports for consistency.

Also document that wxLC_EDIT_LABELS flag is required in EditLabel()
description.

See #23024.

docs/changes.txt

@@ -56,6 +56,9 @@ Changes in behaviour not resulting in compilation errors
   used instead, but if you do use it, you need to update your code to prevent
   the last character of the data from being chopped.
 
+- Calling wxListCtrl::EditLabel() now asserts if the control doesn't have
+  wxLC_EDIT_LABELS style: previously this silently didn't work in wxMSW.
+
 
 Changes in behaviour which may result in build errors
 -----------------------------------------------------

interface/wx/listctrl.h

@@ -453,6 +453,9 @@ public:
         If the user changed the label (i.e. s/he does not press ESC or leave
         the text control without changes, a @c EVT_LIST_END_LABEL_EDIT event
         will be sent which can be vetoed as well.
+
+        Notice that this function should only be called if wxLC_EDIT_LABELS flag
+        is already set on the control. an assertion failure is triggered otherwise.
     */
     wxTextCtrl* EditLabel(long item,
                           wxClassInfo* textControlClass = wxCLASSINFO(wxTextCtrl));

src/generic/listctrl.cpp

@@ -2385,6 +2385,12 @@ void wxListMainWindow::ChangeCurrent(size_t current)
 
 wxTextCtrl *wxListMainWindow::EditLabel(long item, wxClassInfo* textControlClass)
 {
+    // Calling this function for control without wxLC_EDIT_LABELS flag set
+    // is not portable. i.e. on wxMSW this function cannot edit labels if
+    // the flag is not already set on the control.
+    wxASSERT_MSG( HasFlag(wxLC_EDIT_LABELS),
+                 "should only be called if wxLC_EDIT_LABELS flag is set");
+
     wxCHECK_MSG( (item >= 0) && ((size_t)item < GetItemCount()), nullptr,
                  wxT("wrong index in wxGenericListCtrl::EditLabel()") );
 

src/msw/listctrl.cpp

@@ -1753,6 +1753,11 @@ void wxListCtrl::InitEditControl(WXHWND hWnd)
 
 wxTextCtrl* wxListCtrl::EditLabel(long item, wxClassInfo* textControlClass)
 {
+    // This function will fail to edit labels if the wxLC_EDIT_LABELS flag
+    // is not already set on the control.
+    wxASSERT_MSG( HasFlag(wxLC_EDIT_LABELS),
+                 "should only be called if wxLC_EDIT_LABELS flag is set");
+
     wxCHECK_MSG( textControlClass->IsKindOf(wxCLASSINFO(wxTextCtrl)), nullptr,
                   "control used for label editing must be a wxTextCtrl" );
 

src/qt/listctrl.cpp

@@ -1622,6 +1622,12 @@ void wxListCtrl::ClearAll()
 wxTextCtrl* wxListCtrl::EditLabel(long item,
                                   wxClassInfo* WXUNUSED(textControlClass))
 {
+    // Calling this function for control without wxLC_EDIT_LABELS flag set
+    // is not portable. i.e. on wxMSW this function cannot edit labels if
+    // the flag is not already set on the control.
+    wxASSERT_MSG( HasFlag(wxLC_EDIT_LABELS),
+                 "should only be called if wxLC_EDIT_LABELS flag is set");
+
     // Open the editor first so that it's available when handling events as per
     // wx standard.
     const QModelIndex index = m_model->index(item, 0);