[PATCH v3 10/14] win32u: Handle 0 width or height in generate_ellipse_top_half().

[Elizabeth Figura]

From: Elizabeth Figura

---
 dlls/win32u/dibdrv/graphics.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/dlls/win32u/dibdrv/graphics.c b/dlls/win32u/dibdrv/graphics.c
index 36fe965c4b6..1554f8415d0 100644
--- a/dlls/win32u/dibdrv/graphics.c
+++ b/dlls/win32u/dibdrv/graphics.c
@@ -216,11 +216,14 @@ static unsigned int generate_ellipse_top_half( const DC *dc, const RECT *rect, P
      * This point is not on the ellipse axis, but that doesn't matter for our
      * algorithm. We will take this set of points and rotate it 180 degrees
      * to get the opposite side. */
-    x = GDI_ROUND( center_x - sqrt(d / a) ) - center_x;
+    if (!height || !width)
+        x = GDI_ROUND( center_x ) - center_x;
+    else
+        x = GDI_ROUND( center_x - sqrt(d / a) ) - center_x;
     y = GDI_ROUND( center_y ) - center_y;
     start_x = x;

-    while (y > 0 || (y == 0 && x != -start_x))
+    do
     {
         double dx =  (b * x + c * y);
         double dy = -(a * x + b * y);
@@ -274,7 +277,8 @@ static unsigned int generate_ellipse_top_half( const DC *dc, const RECT *rect, P
             if (fabs(sigma2) > fabs(sigma1))
                 y -= y_inc;
         }
-    }
+    } while (y > 0 || (y == 0 && x != -start_x));
+
     return pos;
 }