Fix "Setting window custom cursor from SVG image crashes" (#1363)

FL/Fl_Image.H

@@ -392,9 +392,12 @@ public:
    \sa  void Fl_RGB_Image::max_size(size_t)
    */
   static size_t max_size() {return max_size_;}
-  /** Returns whether an image is an Fl_SVG_Image or not.
+  /** Returns whether an RGB image is an Fl_SVG_Image or not.
   This virtual method returns a pointer to the Fl_SVG_Image if this object is an instance of Fl_SVG_Image or NULL if not. */
   virtual Fl_SVG_Image *as_svg_image() { return NULL; }
+  /** Returns whether an RGB image is an Fl_SVG_Image or not.
+  This virtual method returns a pointer to the Fl_SVG_Image if this object is an instance of const Fl_SVG_Image or NULL if not. */
+  virtual const Fl_SVG_Image *as_svg_image() const { return NULL; }
   /** Makes sure the object is fully initialized.
    In particular, makes sure member variable \ref array is non-null. */
   virtual void normalize() {}

FL/Fl_SVG_Image.H

@@ -170,6 +170,7 @@ public:
   void draw(int X, int Y, int W, int H, int cx = 0, int cy = 0) override;
   void draw(int X, int Y) { draw(X, Y, w(), h(), 0, 0); }
   Fl_SVG_Image *as_svg_image() override { return this; }
+  const Fl_SVG_Image *as_svg_image() const override { return this; }
   void normalize() override;
 };
 

src/Fl_cocoa.mm

@@ -4161,6 +4161,11 @@ int Fl_Cocoa_Window_Driver::set_cursor(const Fl_RGB_Image *image, int hotx, int
   if ((hoty < 0) || (hoty >= image->h()))
     return 0;
 
+  if (image->as_svg_image()) {
+    Fl_RGB_Image *image2 = (Fl_RGB_Image*)image->copy();
+    image2->normalize();
+    image = image2;
+  }
   // OS X >= 10.6 can create a NSImage from a CGImage, but we need to
   // support older versions, hence this pesky handling.
 
@@ -4220,6 +4225,7 @@ int Fl_Cocoa_Window_Driver::set_cursor(const Fl_RGB_Image *image, int hotx, int
 
   [bitmap release];
   [nsimage release];
+  if (image->as_svg_image()) delete image;
 
   return 1;
 }

src/Fl_win32.cxx

@@ -2770,6 +2770,7 @@ int Fl_WinAPI_Window_Driver::set_cursor(Fl_Cursor c) {
 int Fl_WinAPI_Window_Driver::set_cursor(const Fl_RGB_Image *image, int hotx, int hoty) {
   HCURSOR new_cursor;
   Fl_RGB_Image *scaled_image = (Fl_RGB_Image*)image->copy();
+  scaled_image->normalize();
   new_cursor = image_to_icon(scaled_image, false, hotx, hoty);
   delete scaled_image;
   if (new_cursor == NULL)

src/Fl_x.cxx

@@ -3142,11 +3142,13 @@ int Fl_X11_Window_Driver::set_cursor(const Fl_RGB_Image *image, int hotx, int ho
   if ((hoty < 0) || (hoty >= image->h()))
     return 0;
 
-  cursor = XcursorImageCreate(image->w(), image->h());
+  float s = image->as_svg_image() ? Fl::screen_scale(pWindow->screen_num()) : 1;
+  cursor = XcursorImageCreate(image->w() * s, image->h() * s);
   if (!cursor)
     return 0;
 
-  image = (Fl_RGB_Image*)image->copy();
+  image = (Fl_RGB_Image*)image->copy(image->w() * s, image->h() * s);
+  ((Fl_RGB_Image*)image)->normalize();
   const int extra_data = image->ld() ? (image->ld()-image->w()*image->d()) : 0;
   const uchar *i = (const uchar*)*image->data();
   XcursorPixel *o = cursor->pixels;

src/drivers/Wayland/Fl_Wayland_Window_Driver.cxx

@@ -1824,6 +1824,13 @@ int Fl_Wayland_Window_Driver::set_cursor(const Fl_RGB_Image *rgb, int hotx, int
 int Fl_Wayland_Window_Driver::set_cursor_4args(const Fl_RGB_Image *rgb, int hotx, int hoty,
                                                bool keep_copy) {
   if (keep_copy) {
+    if (rgb->as_svg_image()) {
+      int scale = wld_scale();
+      Fl_RGB_Image *svg = (Fl_RGB_Image*)rgb->copy(rgb->w() * scale, rgb->h() * scale);
+      svg->normalize();
+      svg->scale(rgb->w(), rgb->h(), 0, 1);
+      rgb = svg;
+    } else {
       int ld = rgb->ld() ? rgb->ld() : rgb->data_w() * rgb->d();
       uchar *data = new uchar[ld * rgb->data_h()];
       memcpy(data, rgb->array, ld * rgb->data_h());
@@ -1832,6 +1839,7 @@ int Fl_Wayland_Window_Driver::set_cursor_4args(const Fl_RGB_Image *rgb, int hotx
       rgb2->scale(rgb->w(), rgb->h(), 0, 1);
       rgb = rgb2;
     }
+  }
 // build a new wl_cursor and its image
   struct wld_window *xid = (struct wld_window *)Fl_Window_Driver::xid(pWindow);
   struct wl_cursor *new_cursor = (struct wl_cursor*)malloc(sizeof(struct wl_cursor));