Nav, ButtonBehavior: reworked old code which ended up 1) calling SetActiveId repeately and 2) misleadingly set g.NavActivateId (amend af38749e)

imgui_widgets.cpp

@@ -604,13 +604,12 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
         bool nav_activated_by_code = (g.NavActivateId == id);
         bool nav_activated_by_inputs = IsNavInputTest(ImGuiNavInput_Activate, (flags & ImGuiButtonFlags_Repeat) ? ImGuiInputReadMode_Repeat : ImGuiInputReadMode_Pressed);
         if (nav_activated_by_code || nav_activated_by_inputs)
-            pressed = true;
-        if (nav_activated_by_code || nav_activated_by_inputs || g.ActiveId == id)
         {
             // Set active id so it can be queried by user via IsItemActive(), equivalent of holding the mouse button.
-            g.NavActivateId = id; // This is so SetActiveId assign a Nav source
+            pressed = true;
             SetActiveID(id, window);
-            if ((nav_activated_by_code || nav_activated_by_inputs) && !(flags & ImGuiButtonFlags_NoNavFocus))
+            g.ActiveIdSource = ImGuiInputSource_Nav;
+            if (!(flags & ImGuiButtonFlags_NoNavFocus))
                 SetFocusID(id, window);
         }
     }