bash 4.3 "multiple dot" commands fails silently on Fedora

Question

I just noted this on bash 4.3; exact version number is 4.3.42(1)-release (x86-redhat-linux-gnu).

$ ..
$ ...
$ ....
$ .....

Why do the "command not found" is not prompted ?

$ ...
$ echo $? 
$ 127

I checked the $PATH and the alias nothing; The man is not helping neither.
The bash run on Fedora Linux, but I think it is not related to the OS.

EDIT

I just noted this it the same for any dot starting command

.za
.zaza
..za
..zaza

• John Militer: When you do that do you get any response at all?
• Emmanuel: @John Yes it is like I posted here. On my computers I traditionally alias "..." to sudo -s here I forgot to do so, this is how I discovered it.
• derobert: Works as expected on Debian 4.3.42(1)-release. Do you have a command_not_found_handle function?

Answer 1

This was caused by the command-not-found handling in Fedora.

Running an unknown command (including ... etc. if no alias matches) causes command_not_found_handle to be run with the missing command as parameter (see /etc/profile.d/PackageKit.sh for its definition). In the given scenario, the handler then runs /usr/libexec/pk-command-not-found, again with the missing command as parameter. Previously, pk-command-not-found simply ignored any command starting with .:

if (argv[1][0] == '.')
 goto out;

and exited with code 127.

This behaviour was introduced to fix Red Hat #1151185, is also referenced in Bash does not print any error msg upon non-existing commands starting with dot, and has a bug requesting a fix (Red Hat #1292531). It’s largely been fixed in FC 27 with updates, since PackageKit 1.1.8 (see this commit): now commands with leading dots are processed, only . and .. are ignored.

• Emmanuel: Thank you, I think I will consider to use a different shell.
• cas: @Emmanuel or you could just disable Fedora's broken command-not-found handler with something like unset -f command_not_found_handle in your ~/.bashrc. Or uninstall whatever Fedora package is providing the command-not-found functionality (on debian, I run apt-get purge command-not-found on every debian box i build. I do the same for the bash-completion package. Both are far more annoying than any benefit they bring)
• mattdm: Note that whatever this bug was, it's fixed now.
• mattdm: @StephenKitt Hmmm, weird. Not on mine. I get "command not found" in most of the example cases, and additionally Similar command is: '..' with ....
• mattdm: Actually, following your github link in your answer now shows fixed code. This commit from two months ago did it — instead of just looking for a starting ., it checks explicitly for . and ...