I recently installed GVim and set the font to DejaVu Sans Mono size 11, but I noticed that there are 2 pixel lines between the lines, making the lines look apart. With linespace set to -2, the spacing looks correct (I compared it with gedit), but it has problem with some characters, for example, the underscore '_' cannot be displayed. Is this a bug in GVim? I am using Ubuntu 15.04.
Here is a screenshot comparing GVim and gedit side by side, http://i.imgur.com/0GRFNLx.png
EDIT: add a screenshot