Issue with spacing when using WebDevIconsNerdTreeAfterGlyphPadding
let g:WebDevIconsNerdTreeAfterGlyphPadding = ' '

± nvim --version
NVIM 0.1.7
Build type: RelWithDebInfo
Compilation: /usr/local/Homebrew/Library/Homebrew/shims/super/clang -Wconversion -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1 -O2 -g -DDISABLE_LOG -Wall -Wextra -pedantic -Wno-unused-parameter -Wstrict-prototypes -std=gnu99 -Wvla -fstack-protector-strong -fdiagnostics-color=auto -DINCLUDE_GENERATED_DECLARATIONS -DHAVE_CONFIG_H -I/tmp/neovim-20161202-25906-1xcct63/neovim-0.1.7/build/config -I/tmp/neovim-20161202-25906-1xcct63/neovim-0.1.7/src -I/usr/local/include -I/usr/local/include -I/usr/local/include -I/usr/local/include -I/usr/local/include -I/usr/local/opt/gettext/include -I/usr/include -I/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/include -I/tmp/neovim-20161202-25906-1xcct63/neovim-0.1.7/build/src/nvim/auto -I/tmp/neovim-20161202-25906-1xcct63/neovim-0.1.7/build/include
platform: osx 10.12.1
devicons: 0.8.5
iTerm2: 3.0.12
also on a side note, I'm randomly seeing ].

I can confirm the spacing issue happens even without setting WebDevIconsNerdTreeAfterGlyphPadding, it is actually to do with setting DevIconsEnableFoldersOpenClose and also it doesn't matter what WebDevIconsUnicodeGlyphDoubleWidth is set to because it is the actual folder open icon that is causing the spacing to be affected. It appears that the folder open icon has a different width to the folder closed icon...
I also have the square brackets issue in neovim.
I investigated this a bit further and I get the issue with these settings:
let NERDTreeDirArrowExpandable = " "
let NERDTreeDirArrowCollapsible = " "
Note that the space between the quotes is a non-breaking space
When I let NERDTree show the directory arrows with the default characters, I don't get the square brackets.
vim version: NVIM v0.2.2
os version: osx 10.13.2
devicons: current master
I have a similar problem, this [ always appears in front of my first undeployed folder Icon.

I investigated this a bit further and I get the issue with these settings:
let NERDTreeDirArrowExpandable = " " let NERDTreeDirArrowCollapsible = " "Note that the space between the quotes is a non-breaking space
When I let NERDTree show the directory arrows with the default characters, I don't get the square brackets.
vim version:
NVIM v0.2.2os version: osx 10.13.2 devicons: current master
Thanks, this was my problem as-well in vim 8.2.
Using ">" and "v" for NERDTree caused my issue, but changing it to use a fancy Unicode arrow worked fine. Must be some conflict in the code.