patch 7.4.1513
Problem:    "J" fails if there are not enough lines. (Christian Neukirchen)
Solution:   Reduce the count, only fail on the last line.
diff --git a/src/testdir/test_alot.vim b/src/testdir/test_alot.vim
index 3ceece3..d7718ff 100644
--- a/src/testdir/test_alot.vim
+++ b/src/testdir/test_alot.vim
@@ -6,6 +6,7 @@
 source test_delete.vim
 source test_expand.vim
 source test_glob2regpat.vim
+source test_join.vim
 source test_lispwords.vim
 source test_menu.vim
 source test_reltime.vim
diff --git a/src/testdir/test_join.vim b/src/testdir/test_join.vim
new file mode 100644
index 0000000..8a028f1
--- /dev/null
+++ b/src/testdir/test_join.vim
@@ -0,0 +1,13 @@
+" Test for joining lines.
+
+func Test_join_with_count()
+  new
+  call setline(1, ['one', 'two', 'three', 'four'])
+  normal J
+  call assert_equal('one two', getline(1))
+  %del
+  call setline(1, ['one', 'two', 'three', 'four'])
+  normal 10J
+  call assert_equal('one two three four', getline(1))
+  quit!
+endfunc