minor fixes and cleanup

Author: otuncelli

SVGType/SvgType.cs

@@ -14,7 +14,7 @@ public class SvgType : FileType
     {
         public SvgType()
             : base(
-                "Scalable Vector Graphics", 
+                "Scalable Vector Graphics",
                 FileTypeFlags.SupportsLoading,
                 new[] {".svg", ".svgz"})
         {
@@ -35,6 +35,8 @@ private static Form GetMainForm()
 
         private static bool IsCompressed(Stream input)
         {
+            if (input.Length < 3)
+                return false;
             var headerBytes = new byte[3];
             input.Read(headerBytes, 0, 3);
             input.Position = 0;
@@ -43,57 +45,67 @@ private static bool IsCompressed(Stream input)
 
         protected override Document OnLoad(Stream input)
         {
-            if(IsCompressed(input))
+            if (IsCompressed(input))
                 input = new GZipStream(input, CompressionMode.Decompress);
+
+            SvgDocument doc;
             using (input)
             {
-                var doc = SvgDocument.Open<SvgDocument>(input);
-                bool keepAspectRatio;
-                int resolution;
-                int canvasw;
-                int canvash;
+                doc = SvgDocument.Open<SvgDocument>(input);
+            }
+
+            bool keepAspectRatio;
+            int resolution;
+            int canvasw;
+            int canvash;
+            var vpw = 0;
+            var vph = 0;
+            if (!doc.Width.IsNone && !doc.Width.IsEmpty &&
+                doc.Width.Type != SvgUnitType.Percentage)
+                vpw = (int) doc.Width.Value;
+            if (!doc.Height.IsNone && !doc.Height.IsEmpty &&
+                doc.Height.Type != SvgUnitType.Percentage)
+                vph = (int) doc.Height.Value;
+            var vbx = (int) doc.ViewBox.MinX;
+            var vby = (int) doc.ViewBox.MinY;
+            var vbw = (int) doc.ViewBox.Width;
+            var vbh = (int) doc.ViewBox.Height;
+            DialogResult dr = DialogResult.Cancel;
+            using (var dialog = new UIDialog())
+            {
                 Form mainForm = GetMainForm();
-                var dr = DialogResult.Cancel;
-                using (var dialog = new UIDialog())
+                if (mainForm != null)
                 {
                     mainForm.Invoke((MethodInvoker) (() =>
                     {
-                        int vpw = 0;
-                        int vph = 0;
-                        if (!doc.Width.IsNone && !doc.Width.IsEmpty &&
-                            doc.Width.Type != SvgUnitType.Percentage)
-                            vpw = (int) doc.Width.Value;
-                        if (!doc.Height.IsNone && !doc.Height.IsEmpty &&
-                            doc.Height.Type != SvgUnitType.Percentage)
-                            vph = (int) doc.Height.Value;
-                        var vbx = (int) doc.ViewBox.MinX;
-                        var vby = (int) doc.ViewBox.MinY;
-                        var vbw = (int) doc.ViewBox.Width;
-                        var vbh = (int) doc.ViewBox.Height;
                         dialog.SetSvgInfo(vpw, vph, vbx, vby, vbw, vbh);
                         dr = dialog.ShowDialog(mainForm);
                     }));
-                    if (dr != DialogResult.OK)
-                        throw new OperationCanceledException("Cancelled by user");
-                    canvasw = dialog.CanvasW;
-                    canvash = dialog.CanvasH;
-                    resolution = dialog.Dpi;
-                    keepAspectRatio = dialog.KeepAspectRatio;
                 }
-                var bmp = new Bitmap(canvasw, canvash);
-                using (Graphics graph = Graphics.FromImage(bmp))
-                using (ISvgRenderer renderer = SvgRenderer.FromGraphics(graph))
+                else
                 {
-                    doc.Ppi = resolution;
-                    doc.Width = new SvgUnit(SvgUnitType.Pixel, canvasw);
-                    doc.Height = new SvgUnit(SvgUnitType.Pixel, canvash);
-                    doc.AspectRatio = keepAspectRatio
-                        ? new SvgAspectRatio(SvgPreserveAspectRatio.xMinYMin)
-                        : new SvgAspectRatio(SvgPreserveAspectRatio.none);
-                    doc.Draw(renderer);
+                    dialog.SetSvgInfo(vpw, vph, vbx, vby, vbw, vbh);
+                    dr = dialog.ShowDialog();
                 }
-                return Document.FromImage(bmp);
+                if (dr != DialogResult.OK)
+                    throw new OperationCanceledException("Cancelled by user");
+                canvasw = dialog.CanvasW;
+                canvash = dialog.CanvasH;
+                resolution = dialog.Dpi;
+                keepAspectRatio = dialog.KeepAspectRatio;
+            }
+            var bmp = new Bitmap(canvasw, canvash);
+            using (Graphics graph = Graphics.FromImage(bmp))
+            {
+                doc.Ppi = resolution;
+                doc.Width = new SvgUnit(SvgUnitType.Pixel, canvasw);
+                doc.Height = new SvgUnit(SvgUnitType.Pixel, canvash);
+                doc.AspectRatio = keepAspectRatio
+                    ? new SvgAspectRatio(SvgPreserveAspectRatio.xMinYMin)
+                    : new SvgAspectRatio(SvgPreserveAspectRatio.none);
+                doc.Draw(graph);
             }
+            return Document.FromImage(bmp);
         }
     }
 }