Nice work. I think I'm now a fan of sending videos with bug reports. I was definitely not testing the same way as you were, so I now understand what you are seeing. Apologies for any misunderstanding. Add Files/Tree still works the same way I described, the initial directory is still the current directory, as you would see in the when you type cd on the command-line. Nothing has changed there. However, a change *did* happen somewhere between 12.0.0 and 12.0.2 in the Choose Directory (_cd_form) works that would have caused this. In previous builds, when you would browse directories using the ... button on the project form, the working directory would get changed while you were browsing, and this actually lead to some undesirable side effects. So we did make a change, just not directly to the project properties form.
What you may want to do is to modify the Add Files callback handler to use the project Working Directory as the initial directory. In project.e, in _add.lbutton_up() handler (line 4786), you can set the initial directory to the _OpenDialog code from:
typeless result=_OpenDialog("-modal "_stdform("_open_form"),
'Add Source Files',// title
_last_wildcards,// Initial wildcards
def_file_types','EXTRA_FILE_FILTERS,
OFN_NOCHANGEDIR|OFN_FILEMUSTEXIST|OFN_ALLOWMULTISELECT|OFN_SET_LAST_WILDCARDS,
"", // Default extension
""/*wildcards*/, // Initial filename
"",// Initial directory
"",
"",
projectPropertiesAddFilesCallback); // include item callback
to
typeless result=_OpenDialog("-modal "_stdform("_open_form"),
'Add Source Files',// title
_last_wildcards,// Initial wildcards
def_file_types','EXTRA_FILE_FILTERS,
OFN_NOCHANGEDIR|OFN_FILEMUSTEXIST|OFN_ALLOWMULTISELECT|OFN_SET_LAST_WILDCARDS,
"", // Default extension
""/*wildcards*/, // Initial filename
_prjworking_dir.p_text,// Initial directory
"",
"",
projectPropertiesAddFilesCallback); // include item callback
_prjworking_dir.p_text is the edit control which stores the project working directory for that particular project/config.