Please describe the problem.

IMHO annex shouldn't redownload the file (not yet under annex/git control) entirely if pointed by --file=FILE FILE exists.

[[!format sh """

$> chmod a+w -R /tmp/123; rm -rf /tmp/123; mkdir /tmp/123; cd /tmp/123; git init; git annex init;
Initialized empty Git repository in /tmp/123/.git/
init ok

$> wget -q http://www.onerussian.com/tmp/banner.png

$> ls -l total 28 -rw------- 1 yoh yoh 25319 Sep 17 13:49 banner.png

$> git annex addurl --file=banner.png http://www.onerussian.com/tmp/banner.png addurl banner.png (downloading http://www.onerussian.com/tmp/banner.png ...) /tmp/123/.git/annex/tmp/URL-s25319--http&c%%w 100%[=================================================================================================>] 24.73K --.-KB/s in 0.003s
ok

$> git annex version git-annex version: 6.20160104+gitg0cf96be-1~ndall+1

"""]

I don't think that the re-download is the bug. The actual problem is that the file is present and not an annexed file, so git-annex addurl should avoid overwriting it, whatever its content. fixed --Joey