Pressing TAB right after 'git command --long-option=' results in
'git command --long-option=--long-option=' when the long option requires
an argument, but we don't provide completion for its arguments (e.g.
commit --author=, apply --exclude=). This patch detects these long
options and provides empty completion array for them.
Signed-off-by: SZEDER Gábor <szeder@ira.uka.de> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>