Many years ago I was pissed off by Vim's change to start "leaking" comments. If you hit enter on a comment line, Vim's artificial stupidity system deduces, that the next line is also a comment and "helps" you by adding a comment character for you. If you are copy/pasting stuff, which is already formatted, all you'll get is bunch of garbage. The obvious fix is to run a colon (:)-command: :set formatoptions-=cro
Even that failed at some point, but luckily they made changes to get that working again. My old post from year 2013 is here:
Quite soon you'll find out, that you need to m a n u a l l y do that every single time you start editing a file. Argh! Annoying. There must be a way to change something in a configuration file to keep the thing working properly.
In Stackexchange, there is an article set formatoptions in vimrc is being ignored. Yes, just having set formatoptions-=cro in your ~/.vimrc (or ~/.vim/vimrc) won't fix the problem. From the article you find out, that in Vim, there is an after plugin/file type/etc. config-file. Yet again, having a ~/.vim/after/ftplugin.vim containing the precious set formatoptions-=cro will NOT fix the issue.
A second Stackexchange article Why does Vim ignore files in ~/.vim/after/ftplugin? yields almost nothing useful. Almost. By running suggested :scriptnames you will find out, that after/ftplugin.vim is run on a rather low priority. Much before the file-type plugin for chosen language.
Here is an example, I was editing a Ruby-file (extension .rb). When the file was open in Vim, :scriptnames output would say:
1: /etc/vimrc
2: /usr/share/vim/vim74/syntax/syntax.vim
3: /usr/share/vim/vim74/syntax/synload.vim
4: /usr/share/vim/vim74/syntax/syncolor.vim
5: /usr/share/vim/vim74/filetype.vim
6: /usr/share/vim/vim74/ftplugin.vim
7: ~/.vim/after/ftplugin.vim
8: ~/.vim/vimrc
9: /usr/share/vim/vim74/plugin/getscriptPlugin.vim
10: /usr/share/vim/vim74/plugin/gzip.vim
11: /usr/share/vim/vim74/plugin/matchparen.vim
12: /usr/share/vim/vim74/plugin/netrwPlugin.vim
13: /usr/share/vim/vim74/plugin/rrhelper.vim
14: /usr/share/vim/vim74/plugin/spellfile.vim
15: /usr/share/vim/vim74/plugin/tarPlugin.vim
16: /usr/share/vim/vim74/plugin/tohtml.vim
17: /usr/share/vim/vim74/plugin/vimballPlugin.vim
18: /usr/share/vim/vim74/plugin/zipPlugin.vim
19: /usr/share/vim/vim74/syntax/ruby.vim
20: /usr/share/vim/vim74/ftplugin/ruby.vim
There is no way for my "suggestion" to affect the Ruby file-type plugin. It is ran last with highest possible priority!
This time I was ready to go all the way. If fixing this would require making changes to Vim source code, I was ready for battle. Bring it on Vim! Bring your A-game!
My initial weapon-of-choice is mostly strace. It revealed following:
stat("/usr/share/vim/vimfiles/after/syntax/syncolor.vim", 0x7fff45b
stat("/home/joeuser/.vim/after/syntax/syncolor.vim", 0x7fff45bf5610
openat(AT_FDCWD, "/usr/share/vim/vimfiles/after/ftdetect/", O_RDONL
openat(AT_FDCWD, "/home/joeuser/.vim/after/ftdetect/", O_RDONLY|O_N
stat("/usr/share/vim/vimfiles/after/filetype.vim", 0x7fff45bf5f10)
stat("/home/joeuser/.vim/after/filetype.vim", 0x7fff45bf5f10) = -1
stat("/usr/share/vim/vimfiles/after/filetype.vim", 0x7fff45bf6fb0)
stat("/home/joeuser/.vim/after/filetype.vim", 0x7fff45bf6fb0) = -1
stat("/usr/share/vim/vimfiles/after/ftplugin.vim", 0x7fff45bf6fb0)
stat("/home/joeuser/.vim/after/ftplugin.vim", {st_mode=S_IFREG|0644
stat("/home/joeuser/.vim/after/ftplugin.vim", {st_mode=S_IFREG|0644
stat("/home/joeuser/.vim/after/ftplugin.vim", {st_mode=S_IFREG|0644
stat("/home/joeuser/.vim/after/ftplugin.vim", {st_mode=S_IFREG|0644
open("/home/joeuser/.vim/after/ftplugin.vim", O_RDONLY) = 4
stat("/home/joeuser/.vim/after/ftplugin.vim", {st_mode=S_IFREG|0644
openat(AT_FDCWD, "/usr/share/vim/vimfiles/after/plugin/", O_RDONLY|
openat(AT_FDCWD, "/usr/share/vim/vimfiles/after/plugin/", O_RDONLY|
openat(AT_FDCWD, "/home/joeuser/.vim/after/plugin/", O_RDONLY|O_NON
openat(AT_FDCWD, "/home/joeuser/.vim/after/plugin/", O_RDONLY|O_NON
stat("/usr/share/vim/vimfiles/after/syntax/ruby.vim", 0x7fff45bf3b5
openat(AT_FDCWD, "/usr/share/vim/vimfiles/after/syntax/ruby/", O_RD
stat("/home/joeuser/.vim/after/syntax/ruby.vim", 0x7fff45bf3b50) =
openat(AT_FDCWD, "/home/joeuser/.vim/after/syntax/ruby/", O_RDONLY|
...
stat("/root/.vim/ftplugin/ruby.vim", 0x7ffd6abd1990) =
stat("/usr/share/vim/vimfiles/ftplugin/ruby.vim", 0x7ff
stat("/usr/share/vim/vim74/ftplugin/ruby.vim", {st_mode
open("/usr/share/vim/vim74/ftplugin/ruby.vim", O_RDONLY
stat("/usr/share/vim/vim74/ftplugin/ruby.vim", {st_mode
...
stat("/usr/share/vim/vimfiles/after/ftplugin/ruby.vim", 0x7fff45bf4
openat(AT_FDCWD, "/usr/share/vim/vimfiles/after/ftplugin/", O_RDONL
openat(AT_FDCWD, "/usr/share/vim/vimfiles/after/ftplugin/ruby/", O_
stat("/home/joeuser/.vim/after/ftplugin/ruby.vim", 0x7fff45bf4da0)
openat(AT_FDCWD, "/home/joeuser/.vim/after/ftplugin/", O_RDONLY|O_N
openat(AT_FDCWD, "/home/joeuser/.vim/after/ftplugin/ruby/", O_RDONL
After reading and applying file-type plugin for Ruby, Vim does attempt reading a type-specific after-plugin! It will not run the generic one I created, but a language-specific.
Trying that by symlinking the existing generic-for-all-file-types after-plugin file to Ruby:
ln -s $HOME/.vim/after/ftplugin.vim $HOME/.vim/after/ftplugin/ruby.vim
And WHOOO!
It does work! Now, when I start editing a Ruby-file, my formatoptions are without the ridiculous c, r and o. It would be even better to have a generic file-typeless solution, but that one doesn't seem to be available. Also, for the record, this happens both on CentOS 7 vim-7.4.160-5 and Fedora 29 vim-8.1.1137-1. My thinking is, that this problem and fix is not related to the distribution you're running your Vim on.
Nice to have that finally fixed!