Add unit test for wxWrapSizer::CalcMinFromMinor

Add a unit test for a special case of a wrap sizer min size caclulation.
Test wxWrapSizer::CalcMinFromMinor function for this case, when a wrap
sizer used inside a sizer with the same alignment.

tests/sizers/wrapsizer.cpp

@@ -74,3 +74,42 @@ TEST_CASE("wxWrapSizer::CalcMin", "[wxWrapSizer]")
 
     CHECK( sizeMinExpected == sizer->CalcMin() );
 }
+
+TEST_CASE("wxWrapSizer::CalcMinFromMinor", "[wxWrapSizer]")
+{
+    wxScopedPtr<wxWindow> win(new wxWindow(wxTheApp->GetTopWindow(), wxID_ANY));
+    win->SetClientSize(180, 240);
+
+    wxSizer* boxSizer = new wxBoxSizer(wxHORIZONTAL);
+    win->SetSizer(boxSizer);
+
+    // To test CalcMinFromMinor function the wrap sizer with the
+    // horizonral align added to the box sizer with horizontal align.
+    wxSizer* wrapSizer = new wxWrapSizer(wxHORIZONTAL);
+    boxSizer->Add(wrapSizer);
+
+    // Add three child windows. Sum of the first and the second windows widths should
+    // be less than the width of the third window.
+    const wxSize sizeChild1 = wxSize(40, 60);
+    wxWindow * const
+        child1 = new wxWindow(win.get(), wxID_ANY, wxDefaultPosition, sizeChild1);
+    child1->SetBackgroundColour(*wxRED);
+    wrapSizer->Add(child1);
+
+    const wxSize sizeChild2 = wxSize(50, 80);
+    wxWindow * const
+        child2 = new wxWindow(win.get(), wxID_ANY, wxDefaultPosition, sizeChild2);
+    child2->SetBackgroundColour(*wxGREEN);
+    wrapSizer->Add(child2);
+
+    const wxSize sizeChild3 = wxSize(100, 120);
+    wxWindow * const
+        child3 = new wxWindow(win.get(), wxID_ANY, wxDefaultPosition, sizeChild3);
+    child3->SetBackgroundColour(*wxBLUE);
+    wrapSizer->Add(child3);
+
+    // First two windows should be in a first row and the third in a second row.
+    const wxSize sizeMinExpected = wxSize(sizeChild3.x, sizeChild2.y + sizeChild3.y);
+    win->Layout();
+    CHECK(sizeMinExpected == wrapSizer->CalcMin());
+}