tests/test-commit.out

Prevent type exception on concatenation if diffstat returns None.

This will most often occur if diffstat is not installed in the
target platform, though may also happen in other cases where
diffstat fails to execute.

Signed-off-by: Sean Dague <[e-mail]>

% commit date test
abort: impossible time zone offset: 4444444
transaction abort!
rollback completed
abort: invalid date: '1\t15.1' 
transaction abort!
rollback completed
abort: invalid date: 'foo bar' 
transaction abort!
rollback completed
nothing changed
% partial commit test
trouble committing bar!
abort: No such file or directory: .../test/bar
adding dir/file
dir/file
adding dir.file
abort: no match under directory .../test/dir!
abort: no match under directory .../test/bleh!
abort: no match under directory .../test/dir2!
dir/file
does-not-exist: No such file or directory
abort: file .../test/does-not-exist not found!
baz: unsupported file type (type is symbolic link)
abort: can't commit .../test/baz: unsupported file type!
abort: file .../test/quux not tracked!
dir/file
% partial subdir commit test
adding bar/bar
adding foo/foo
% subdir log 1
changeset:   0:6ef3cb06bb80
user:        test
date:        Mon Jan 12 13:46:40 1970 +0000
files:       foo/foo
description:
commit-subdir-1


% subdir log 2
changeset:   1:f2e51572cf5a
tag:         tip
user:        test
date:        Mon Jan 12 13:46:41 1970 +0000
files:       bar/bar
description:
commit-subdir-2


% full log
changeset:   1:f2e51572cf5a
tag:         tip
user:        test
date:        Mon Jan 12 13:46:41 1970 +0000
files:       bar/bar
description:
commit-subdir-2


changeset:   0:6ef3cb06bb80
user:        test
date:        Mon Jan 12 13:46:40 1970 +0000
files:       foo/foo
description:
commit-subdir-1