[bug] first line truncated with `git log --oneline --decorate --graph`

I have a bug using the following command:

    git log --oneline --decorate --graph

In short, the first line of the log is often truncated.

If the terminal is too small to display all the text (~100 columns, and too much text to fit on the high of screen, in this example less than 4 lines), I actually see:

If my history is:

*   4656b73 (HEAD, long_branch_name_and_long_commit_name) Merge commit
'f7f6e4736ad040a1238644a33b681a66c79fac0e' into HEAD
|\
| * f7f6e47 (master) Praesent et diam eget libero egestas mattis sit
amet vitae augue.
| * 8dccb9d Maecenas congue ligula ac quam viverra nec consectetur ante
hendrerit.
|/
* f7724a2 Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec
a diam lectus.

If my screen is not high enough, I see:

1238644a33b681a66c79fac0e' into HEAD
|\ 
| * f7f6e47 (master) Praesent et diam eget libero egestas mattis sit
amet vitae augue.
| * 8dccb9d Maecenas congue ligula ac quam viverra nec consectetur ante
hendrerit.
# next message truncated, because the screen is too small

instead of:
*   4656b73 (HEAD, long_branch_name_and_long_commit_name) Merge commit
'f7f6e4736ad040a1238644a33b681a66c79fac0e' into HEAD
|\
| * f7f6e47 (master) Praesent et diam eget libero egestas mattis sit
amet vitae augue.
| * 8dccb9d Maecenas congue ligula ac quam viverra nec consectetur ante
hendrerit.
# next message truncated, because the screen is too small

As you can see, the first line is truncated.

If I use:
    git log --pretty=oneline --all --decorate --graph
instead of:
    git log --oneline --all --decorate --graph
the problem is the same (first line truncated).

I have see that bug using terminology or xterm, with bash (without .bashrc) or zsh (lots of things in my .zshrc), and my desktop environment is i3/archlinux/git version 2.3.5 It is not a recent regression (if it is, I've learn git one year ago).

# How to reproduce

Open a small terminal windows (4*100)

    mkdir tmp
    cd tmp
    git init
    git commit --allow-empty -m 'Lorem ipsum dolor sit amet, consectetur
adipiscing elit. Donec a diam lectus.'
    git checkout -b long_branch_name_and_long_commit_name
    git commit --allow-empty -m 'Maecenas congue ligula ac quam viverra
nec consectetur ante hendrerit.'
    git commit --allow-empty -m 'Praesent et diam eget libero egestas
mattis sit amet vitae augue.'
    git checkout master
    git merge --no-ff long_branch_name_and_long_commit_name -m 'merge
with a long commit message'
    git checkout long_branch_name_and_long_commit_name
    git merge master
    git log --oneline  --decorate --graph

I hope it is clear. The English is not my mother tongue. -- Robin Moussu //