I have tried to create some missing icons to Editor Toolbar. Analyzing Lazarus source, it looks like Editor Toolbar uses same icons as IDE menu items, so I tried to add an icon to item that was missing it. Following example explains my try to add icon to 'Procedure List' menu item.
Searching through the IDE sources I have found that item in lazarusidestrconsts.pas is defined as
lisMenuProcedureList = 'Procedure List ...';
which lead me to TMainIDEBase.SetupSearchMenu in mainbase.pas:
CreateMenuItem(ParentMI, itmSearchProcedureList, 'itmSearchProcedureList', lisMenuProcedureList);
After further analysis I though that changing that line to
CreateMenuItem(ParentMI, itmSearchProcedureList, 'itmSearchProcedureList', lisMenuProcedureList, 'menu_search_procedure_list');
and then adding appropriate sized PNG icons to \lazarus\images\menu directory:
menu_search_procedure_list.png
menu_search_procedure_list_150.png
menu_search_procedure_list_200.png
and rebuilding IDE would be enough. Unfortunately it is not. What am I missing?