gdiplus: Add a test for extra space added by GdipMeasureString.

dlls/gdiplus/tests/graphics.c

@@ -3892,6 +3892,77 @@ todo_wine
     GdipDeleteStringFormat(format);
 }
 
+static void test_measured_extra_space(void)
+{
+    static const WCHAR tahomaW[] = { 'T','a','h','o','m','a',0 };
+    static const WCHAR string[2] = { 'W','W' };
+    GpStringFormat *format;
+    HDC hdc;
+    GpGraphics *graphics;
+    GpFontFamily *family;
+    GpFont *font;
+    GpStatus status;
+    GpUnit gfx_unit, font_unit;
+    RectF bounds_1, bounds_2, rect;
+    REAL margin, font_size, dpi;
+
+    status = GdipCreateStringFormat(0, LANG_NEUTRAL, &format);
+    expect(Ok, status);
+
+    status = GdipCreateFontFamilyFromName(tahomaW, NULL, &family);
+    expect(Ok, status);
+    hdc = CreateCompatibleDC(0);
+    status = GdipCreateFromHDC(hdc, &graphics);
+    expect(Ok, status);
+
+    status = GdipGetDpiX(graphics, &dpi);
+    expect(Ok, status);
+
+    /* UnitPixel = 2, UnitPoint = 3, UnitInch = 4, UnitDocument = 5, UnitMillimeter = 6 */
+    /* UnitPixel as a font base unit is not tested because it differs in behaviour */
+    for (font_unit = 3; font_unit <= 6; font_unit++)
+    {
+        status = GdipCreateFont(family, 1234.0, FontStyleRegular, font_unit, &font);
+        expect(Ok, status);
+
+        status = GdipGetFontSize(font, &font_size);
+        expect(Ok, status);
+        font_size = units_to_pixels(font_size, font_unit, dpi);
+        /*trace("font size/6 = %f pixels\n", font_size / 6.0);*/
+
+        /* UnitPixel = 2, UnitPoint = 3, UnitInch = 4, UnitDocument = 5, UnitMillimeter = 6 */
+        for (gfx_unit = 2; gfx_unit <= 6; gfx_unit++)
+        {
+            status = GdipSetPageUnit(graphics, gfx_unit);
+            expect(Ok, status);
+
+            /* bounds.width of 1 glyph: [margin]+[width]+[margin] */
+            set_rect_empty(&rect);
+            set_rect_empty(&bounds_1);
+            status = GdipMeasureString(graphics, string, 1, font, &rect, format, &bounds_1, NULL, NULL);
+            expect(Ok, status);
+            /* bounds.width of 2 identical glyphs: [margin]+[width]+[width]+[margin] */
+            set_rect_empty(&rect);
+            set_rect_empty(&bounds_2);
+            status = GdipMeasureString(graphics, string, 2, font, &rect, format, &bounds_2, NULL, NULL);
+            expect(Ok, status);
+
+            /* margin = [bounds.width of 1] - [bounds.width of 2] / 2*/
+            margin = units_to_pixels(bounds_1.Width - bounds_2.Width / 2.0, gfx_unit, dpi);
+            /*trace("margin %f pixels\n", margin);*/
+todo_wine
+            expectf_(font_size / 6.0, margin, font_size / 100.0);
+        }
+
+        GdipDeleteFont(font);
+    }
+
+    GdipDeleteGraphics(graphics);
+    DeleteDC(hdc);
+    GdipDeleteFontFamily(family);
+    GdipDeleteStringFormat(format);
+}
+
 START_TEST(graphics)
 {
     struct GdiplusStartupInput gdiplusStartupInput;
@@ -3918,6 +3989,7 @@ START_TEST(graphics)
 
     GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
 
+    test_measured_extra_space();
     test_measure_string();
     test_font_height_scaling();
     test_transform();