patch 8.1.0390: scrollbars are not tested

Problem:    Scrollbars are not tested.
Solution:   Add test_scrollbar() and a test.

runtime/doc/eval.txt

@@ -2475,6 +2475,8 @@ test_null_partial()		Funcref	null value for testing
 test_null_string()		String	null value for testing
 test_option_not_set({name})    none	reset flag indicating option was set
 test_override({expr}, {val})    none	test with Vim internal overrides
+test_scrollbar({which}, {value}, {dragging})
+				none	scroll in the GUI for testing
 test_settime({expr})		none	set current time for testing
 timer_info([{id}])		List	information about timers
 timer_pause({id}, {pause})	none	pause or unpause a timer
@@ -8773,6 +8775,23 @@ test_override({name}, {val})				*test_override()*
 <		The value of "starting" is saved.  It is restored by: >
 			call test_override('starting', 0)
 
+test_scrollbar({which}, {value}, {dragging})		*test_scrollbar()*
+		Pretend using scrollbar {which} to move it to position
+		{value}.  {which} can be:
+			left	Left scrollbar of the current window
+			right	Right scrollbar of the current window
+			hor	Horizontal scrollbar
+
+		For the vertical scrollbars {value} can be 1 to the
+		line-count of the buffer.  For the horizontal scrollbar the
+		{value} can be between 1 and the maximum line length, assuming
+		'wrap' is not set.
+
+		When {dragging} is non-zero it's like dragging the scrollbar,
+		otherwise it's like clicking in the scrollbar.
+		Only works when the {which} scrollbar actually exists,
+		obviously only when using the GUI.
+
 test_settime({expr})					*test_settime()*
 		Set the time Vim uses internally.  Currently only used for
 		timestamps in the history, as they are used in viminfo, and

src/evalfunc.c

@@ -429,6 +429,9 @@ static void f_test_null_job(typval_T *argvars, typval_T *rettv);
 static void f_test_null_list(typval_T *argvars, typval_T *rettv);
 static void f_test_null_partial(typval_T *argvars, typval_T *rettv);
 static void f_test_null_string(typval_T *argvars, typval_T *rettv);
+#ifdef FEAT_GUI
+static void f_test_scrollbar(typval_T *argvars, typval_T *rettv);
+#endif
 static void f_test_settime(typval_T *argvars, typval_T *rettv);
 #ifdef FEAT_FLOAT
 static void f_tan(typval_T *argvars, typval_T *rettv);
@@ -925,6 +928,9 @@ static struct fst
     {"test_null_string", 0, 0, f_test_null_string},
     {"test_option_not_set", 1, 1, f_test_option_not_set},
     {"test_override",    2, 2, f_test_override},
+#ifdef FEAT_GUI
+    {"test_scrollbar",	3, 3, f_test_scrollbar},
+#endif
     {"test_settime",	1, 1, f_test_settime},
 #ifdef FEAT_TIMERS
     {"timer_info",	0, 1, f_timer_info},
@@ -13202,6 +13208,41 @@ f_test_null_string(typval_T *argvars UNUSED, typval_T *rettv)
     rettv->vval.v_string = NULL;
 }
 
+#ifdef FEAT_GUI
+    static void
+f_test_scrollbar(typval_T *argvars, typval_T *rettv UNUSED)
+{
+    char_u	*which;
+    long	value;
+    int		dragging;
+    scrollbar_T *sb = NULL;
+
+    if (argvars[0].v_type != VAR_STRING
+	    || (argvars[1].v_type) != VAR_NUMBER
+	    || (argvars[2].v_type) != VAR_NUMBER)
+    {
+	EMSG(_(e_invarg));
+	return;
+    }
+    which = get_tv_string(&argvars[0]);
+    value = get_tv_number(&argvars[1]);
+    dragging = get_tv_number(&argvars[2]);
+
+    if (STRCMP(which, "left") == 0)
+	sb = &curwin->w_scrollbars[SBAR_LEFT];
+    else if (STRCMP(which, "right") == 0)
+	sb = &curwin->w_scrollbars[SBAR_RIGHT];
+    else if (STRCMP(which, "hor") == 0)
+	sb = &gui.bottom_sbar;
+    if (sb == NULL)
+    {
+	EMSG2(_(e_invarg2), which);
+	return;
+    }
+    gui_drag_scrollbar(sb, value, dragging);
+}
+#endif
+
     static void
 f_test_settime(typval_T *argvars, typval_T *rettv UNUSED)
 {

src/testdir/test_gui.vim

@@ -667,6 +667,41 @@ func Test_set_guioptions()
   let &guioptions = guioptions_saved
 endfunc
 
+func Test_scrollbars()
+  new
+  " buffer with 200 lines
+  call setline(1, repeat(['one', 'two'], 100))
+  set guioptions+=rlb
+
+  " scroll to move line 11 at top, moves the cursor there
+  call test_scrollbar('left', 10, 0)
+  redraw
+  call assert_equal(1, winline())
+  call assert_equal(11, line('.'))
+
+  " scroll to move line 1 at top, cursor stays in line 11
+  call test_scrollbar('right', 0, 0)
+  redraw
+  call assert_equal(11, winline())
+  call assert_equal(11, line('.'))
+
+  set nowrap
+  call setline(11, repeat('x', 150))
+  redraw
+  call assert_equal(1, wincol())
+  call assert_equal(1, col('.'))
+
+  " scroll to character 11, cursor is moved
+  call test_scrollbar('hor', 10, 0)
+  redraw
+  call assert_equal(1, wincol())
+  call assert_equal(11, col('.'))
+
+  set guioptions&
+  set wrap&
+  bwipe!
+endfunc
+
 func Test_set_guipty()
   let guipty_saved = &guipty
 

src/version.c

@@ -794,6 +794,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    390,
 /**/
     389,
 /**/