I was editing a filename in the file list table, and double-clicked to select one word. Instead the whole filename (not including the extension) got selected. This is not standard macos behavior. Compare to editing a filename in Finder, where double-clicking selects just the word clicked.
I did try just hitting the Return key, and it selects the filename not including the extension, which is what Finder does too if you hit the Return key on a selected file.
A delayed double click on the filename in the File List should select the filename without the extension. I've just tried and it works as expected. Can you try again just to be sure?
Upon re-reading your initial remark, you're referring to a double-click on a word while the filename is already in editing mode.
Does it really select the whole filename for you (given, that it's not a single word)?
Yes, that's correct. To go into more detail, when I double-click, on the second mouse-down, the word I clicked is selected, and then on mouse-up (whether I release immediately or hold the mouse/trackpad button down for a bit), the whole base filename (minus extension) is selected.
This happens for me only with the second double click on the same word. The first double click selects the word, the second the whole base filename (minus extension).
I've made a note to investigate further, although low priority (to set expectations).
I'm not sure what you mean by "second" double click. I have to single-click then wait, to be able to edit any file list field at all (which selects the whole filename, minus extension for a filename). Then when it's editable, if I double-click, the whole filename is again selected.
Note that the bug as reported only happens in the Filename column, not the other columns. Those do select single words on a double click.
No worries on low priority, this has an easy workaround.