I can't believe this hasn't been filed yet, but I haven't found any related ticket, so here we go:
Steps to Reproduce:
1. Tools > Macros > Organize Macros > Libreoffice Basic
2. Click 'Libreoffice Macros' in the tree-list on the left
3. In the same tree-list, pick a macro from any of those system-wide modules, for example Gimmicks.Autotext
(it is important to try with system-wide macros and not with user-defined or document-specific ones, otherwise you won't see the misfeature)
4. Click 'Edit'
5. Try to edit the source code
Nothing happens. Macro is read-only. That wouldn't be an issue, but user really has no way of knowing that this is the case.
A yellow-ish info bar ("this document is read-only") would appear, just like for normal documents. Or it would be indicated in another suitable way that it is futile to try to edit this macro
User Profile Reset:
User-Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:47.0) Gecko/20100101 Firefox/47.0
yeah, cool, isn't it ;)