'linebreak' breaks c% if the last visual selection was block

Précis: when the 'linebreak' option is set and visual block mode was the
last visual mode entered, c% removes the text for deletion in a blockwise
manner rather than the character-wise manner that should be the case.

Detailed steps to reproduce (no special configuration is required;
vim -u NONE exhibits the buggy behaviour):

Enter this demonstrative text:

abcd{ef
ghijklm
no}pqrs

Go to the opening {.

Enter and exit visual block mode (<C-V><C-V>).

At some point no later than this, :set linebreak.

c%<Esc>

The expected contents of the buffer is this:

abcdpqrs

The actual contents of the buffer is this:

abef
ghlm
nors

I haven’t experimented much more, but d% is not buggy.

I am using Vim 7.4.778 on Arch Linux, 64-bit (huge with GTK2 GUI).

Original issue reported on code.google.com by chris.morganiser on 30 Jul 2015 at 9:21

zuloloxi / vim_7_4_826

'linebreak' breaks c% if the last visual selection was block #389