patch 8.1.1932: ml_get errors after using append()

Problem:    Ml_get errors after using append(). (Alex Genco)
Solution:   Do not update the cursor twice. (closes #1737)

src/evalfunc.c

@@ -1440,8 +1440,14 @@ set_buffer_lines(
 	tabpage_T   *tp;
 
 	appended_lines_mark(append_lnum, added);
+
+	// Only adjust the cursor for buffers other than the current, unless it
+	// is the current window.  For curbuf and other windows it has been
+	// done in mark_adjust_internal().
 	FOR_ALL_TAB_WINDOWS(tp, wp)
-	    if (wp->w_buffer == buf && wp->w_cursor.lnum > append_lnum)
+	    if (wp->w_buffer == buf
+		    && (wp->w_buffer != curbuf || wp == curwin)
+		    && wp->w_cursor.lnum > append_lnum)
 		wp->w_cursor.lnum += added;
 	check_cursor_col();
 	update_topline();

src/testdir/test_functions.vim

@@ -705,6 +705,15 @@ func Test_mode()
   set complete&
 endfunc
 
+func Test_append()
+  enew!
+  split
+  call append(0, ["foo"])
+  split
+  only
+  undo
+endfunc
+
 func Test_getbufvar()
   let bnr = bufnr('%')
   let b:var_num = '1234'

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1932,
 /**/
     1931,
 /**/