vim-patch:7.4.2279

Problem:    Starting diff mode with the cursor in the last line might end up
            only showing one closed fold. (John Beckett)
Solution:   Scroll the window to show the same relative cursor position.

https://github.com/vim/vim/commit/46328f9a1cc8047d1e05095bc9f531038c5a4028

3 files changed, 17 insertions, 3 deletions

diff --git a/src/nvim/diff.c b/src/nvim/diff.c
index 9cb0789400..5940dc55da 100644
--- a/src/nvim/diff.c
+++ b/src/nvim/diff.c
@@ -1007,6 +1007,10 @@ void ex_diffsplit(exarg_T *eap)
   bufref_T old_curbuf;
   set_bufref(&old_curbuf, curbuf);
 
+  // Need to compute w_fraction when no redraw happened yet.
+  validate_cursor();
+  set_fraction(curwin);
+
   // don't use a new tab page, each tab page has its own diffs
   cmdmod.tab = 0;
 
@@ -1032,6 +1036,9 @@ void ex_diffsplit(exarg_T *eap)
               curwin->w_cursor.lnum);
         }
       }
+      // Now that lines are folded scroll to show the cursor at the same
+      // relative position.
+      scroll_to_fraction(curwin, curwin->w_height);
     }
   }
 }
diff --git a/src/nvim/version.c b/src/nvim/version.c
index befcc918cc..ee2288e1b0 100644
--- a/src/nvim/version.c
+++ b/src/nvim/version.c
@@ -161,7 +161,7 @@ static int included_patches[] = {
   // 2282 NA
   // 2281 NA
   // 2280,
-  // 2279,
+  2279,
   // 2278 NA
   2277,
   // 2276,
diff --git a/src/nvim/window.c b/src/nvim/window.c
index 510f182353..28269e8889 100644
--- a/src/nvim/window.c
+++ b/src/nvim/window.c
@@ -4717,8 +4717,6 @@ void set_fraction(win_T *wp)
  */
 void win_new_height(win_T *wp, int height)
 {
-  linenr_T lnum;
-  int sline, line_size;
   int prev_height = wp->w_height;
 
   /* Don't want a negative height.  Happens when splitting a tiny window.
@@ -4745,6 +4743,15 @@ void win_new_height(win_T *wp, int height)
   wp->w_height = height;
   wp->w_skipcol = 0;
 
+  scroll_to_fraction(wp, prev_height);
+}
+
+void scroll_to_fraction(win_T *wp, int prev_height)
+{
+    linenr_T lnum;
+    int sline, line_size;
+    int height = wp->w_height;
+
   /* Don't change w_topline when height is zero.  Don't set w_topline when
    * 'scrollbind' is set and this isn't the current window. */
   if (height > 0