patch 7.4.2123
Problem: No new style test for diff mode.
Solution: Add a test. Check that folds are in sync.
diff --git a/src/testdir/test_diffmode.vim b/src/testdir/test_diffmode.vim
new file mode 100644
index 0000000..e5d9ff9
--- /dev/null
+++ b/src/testdir/test_diffmode.vim
@@ -0,0 +1,165 @@
+" Tests for diff mode
+
+func Test_diff_fold_sync()
+ enew!
+ let l = range(50)
+ call setline(1, l)
+ diffthis
+ let winone = win_getid()
+ new
+ let l[25] = 'diff'
+ call setline(1, l)
+ diffthis
+ let wintwo = win_getid()
+ " line 15 is inside the closed fold
+ call assert_equal(19, foldclosedend(10))
+ call win_gotoid(winone)
+ call assert_equal(19, foldclosedend(10))
+ " open the fold
+ normal zv
+ call assert_equal(-1, foldclosedend(10))
+ " fold in other window must have opened too
+ call win_gotoid(wintwo)
+ call assert_equal(-1, foldclosedend(10))
+
+ " cursor position is in sync
+ normal 23G
+ call win_gotoid(winone)
+ call assert_equal(23, getcurpos()[1])
+
+ windo diffoff
+ close!
+ set nomodified
+endfunc
+
+func Test_vert_split()
+ " Disable the title to avoid xterm keeping the wrong one.
+ set notitle noicon
+ new
+ let l = ['1 aa', '2 bb', '3 cc', '4 dd', '5 ee']
+ call setline(1, l)
+ w! Xtest
+ normal dd
+ $
+ put
+ normal kkrXoxxx
+ w! Xtest2
+ file Nop
+ normal ggoyyyjjjozzzz
+ set foldmethod=marker foldcolumn=4
+ call assert_equal(0, &diff)
+ call assert_equal('marker', &foldmethod)
+ call assert_equal(4, &foldcolumn)
+ call assert_equal(0, &scrollbind)
+ call assert_equal(0, &cursorbind)
+ call assert_equal(1, &wrap)
+
+ vert diffsplit Xtest
+ vert diffsplit Xtest2
+ call assert_equal(1, &diff)
+ call assert_equal('diff', &foldmethod)
+ call assert_equal(2, &foldcolumn)
+ call assert_equal(1, &scrollbind)
+ call assert_equal(1, &cursorbind)
+ call assert_equal(0, &wrap)
+
+ let diff_fdm = &fdm
+ let diff_fdc = &fdc
+ " repeat entering diff mode here to see if this saves the wrong settings
+ diffthis
+ " jump to second window for a moment to have filler line appear at start of
+ " first window
+ wincmd w
+ normal gg
+ wincmd p
+ normal gg
+ call assert_equal(2, winline())
+ normal j
+ call assert_equal(4, winline())
+ normal j
+ call assert_equal(5, winline())
+ normal j
+ call assert_equal(6, winline())
+ normal j
+ call assert_equal(8, winline())
+ normal j
+ call assert_equal(9, winline())
+
+ wincmd w
+ normal gg
+ call assert_equal(1, winline())
+ normal j
+ call assert_equal(2, winline())
+ normal j
+ call assert_equal(4, winline())
+ normal j
+ call assert_equal(5, winline())
+ normal j
+ call assert_equal(8, winline())
+
+ wincmd w
+ normal gg
+ call assert_equal(2, winline())
+ normal j
+ call assert_equal(3, winline())
+ normal j
+ call assert_equal(4, winline())
+ normal j
+ call assert_equal(5, winline())
+ normal j
+ call assert_equal(6, winline())
+ normal j
+ call assert_equal(7, winline())
+ normal j
+ call assert_equal(8, winline())
+
+ " Test diffoff
+ diffoff!
+ 1wincmd 2
+ let &diff = 1
+ let &fdm = diff_fdm
+ let &fdc = diff_fdc
+ 4wincmd w
+ diffoff!
+ 1wincmd w
+ call assert_equal(0, &diff)
+ call assert_equal('marker', &foldmethod)
+ call assert_equal(4, &foldcolumn)
+ call assert_equal(0, &scrollbind)
+ call assert_equal(0, &cursorbind)
+ call assert_equal(1, &wrap)
+
+ wincmd w
+ call assert_equal(0, &diff)
+ call assert_equal('marker', &foldmethod)
+ call assert_equal(4, &foldcolumn)
+ call assert_equal(0, &scrollbind)
+ call assert_equal(0, &cursorbind)
+ call assert_equal(1, &wrap)
+
+ wincmd w
+ call assert_equal(0, &diff)
+ call assert_equal('marker', &foldmethod)
+ call assert_equal(4, &foldcolumn)
+ call assert_equal(0, &scrollbind)
+ call assert_equal(0, &cursorbind)
+ call assert_equal(1, &wrap)
+
+ windo bw!
+endfunc
+
+func Test_filler_lines()
+ " Test that diffing shows correct filler lines
+ enew!
+ put =range(4,10)
+ 1d _
+ vnew
+ put =range(1,10)
+ 1d _
+ windo diffthis
+ wincmd h
+ call assert_equal(1, line('w0'))
+ unlet! diff_fdm diff_fdc
+
+ windo bw!
+endfunc