Comment 17 for bug 90378

Well, I guess it all depends on how we look at the problem...

I can understand why you say that Firefox behaves correctly by saving downloads as read-only, but then would that mean that wget behaves wrongly by saving downloads with user-set permissions? I don't think so. It all depends on the use-case scenario, ie. it all depends on what the user wants to actually do with the file, but this is of course, we don't know.

On certain use-case scenarios, saving read-only is annoying because the target application may behave unexpectedly because of the file's permissions (the OpenOffice case, for example). Let's name this the JohnnyBrowser's use-case scenario. On other use-case scenarios, saving with write permissions can mislead the user to believe that he has saved a file that will be swept away. Say this is JohnnyKeeper's use-case scenario.

The problem here is that you must take a decision. Our goal here should be to try annoying users the least possible.

Say we save with write permissions: user JohnnyKeeper will eventually learn that if he does not "save as" his downloads to a well-known directory, he ends up loosing them. It will cost him a few data losses, but he will eventually learn and live happily ever after. User JohhnyBrowser leaves happily.
On a daily basis, here is what these 2 guys end up doing:
JohnnyKeeper opens a document, edits it, then does a "save as", chooses a new file name, saves, then closes application.
JohhnyBrowser opens a document, edits it, then closes application.

Say we save with read-only permissions: user JohnnyKeeper will eventually learn that he can't save directly, but must first do a "save as" if he wants to keep/edit the downloaded file. He will never loose data, and live happily ever after. User JohnnyBrowser will eventually learn that with certain downloads he can't edit directly, but must first do a "save as". He will never live happily, wondering why he must save and name a file he does not want to keep anyway.
On a daily basis, here is what these 2 guys end up doing:
JohnnyKeeper opens a document, then does a "save as", chooses a new file name, saves, edits the file, then saves, then closes application.
JohhnyBrowser opens a document, then does a "save as", chooses a new file name, saves, edits the file, then closes application.

If we save read-only, both users end up doing more tasks (on certain apps, of course), and in some cases they end up doing tasks that have nothing to do with their goals.