Adding new characters cause splitting line into many lines

Question

I'm analyzing a lot of logs using VIM version 7.3 (2010 Aug 15, compiled Sep 24 2013 13:45:11).
Recently I obtained logs that look like this:

     3521:2015-09-28T09:18:36.922557+00:00 192 [info]  »   ERR:  00 LINUX-0-<2015-09-28T09:18:36.922555Z> 22E ERR/APP/Error, (pid:558) name : SomeApplication#015¶

but after inserting any word at the end of a line it changes to 3 lines like so:

3521:2015-09-28T09:18:36.922557+00:00 192 [info]  »   ERR:  00¶
LINUX-0-<2015-09-28T09:18:36.922555Z> 22E ERR/APP/Error, (pid:558) name :¶
SomeApplication#015 %%%¶

My .vimrc:

set cindent¶
set nowrap¶
set hidden¶
set number¶
set ignorecase¶
set tabstop=6 shiftwidth=4 softtabstop=4 expandtab¶
set listchars=tab:»\ ,eol:¶,trail:·,   " show invisible characters as in eclipse IDE¶
nmap <CR> o<Esc>¶
nnoremap <silent> <Space> :silent noh<Bar>echo<CR>¶

" user defined commands¶
command DBGPrint ! cat % <Bar> grep \%\%\% <Bar> less¶
command! -nargs=1 Filter %y z <Bar> tabnew <Bar> 0put=@z <Bar> %!grep -in "<args>"¶
command! -nargs=1 FilterSens %y z <Bar> tabnew <Bar> 0put=@z <Bar> %!grep -n "<args>"¶

EDIT:
I added

set textwidth=0
set wrapmargin=0

at the end of my .vimrc file but when opening log file I have it set to textwidth=78.
When I execute set textwidth=0 in open file - it works.

Answer 1

Try set textwidth=0 to not break up long lines. See :h tw. Note that if you set the textwidth to 0, then wrapmargin might take effect, see :h wm, so consider also using set wrapmargin=0.