Fix two rare potential bugs (NULL pointer dereferencing)

Both bugs can happen if a widget doesn't have an associated window()
or in similar situations. These fixes returns NULL to prevent crashes.

Bugs observed in special test scenarios, not real-life programs.
This commit is contained in:
Albrecht Schlosser 2022-11-05 19:31:59 +01:00
parent 918395e091
commit b426a3d7c0
2 changed files with 2 additions and 1 deletions

View File

@ -57,7 +57,7 @@ public:
Fl_X *next;
// static variables, static functions and member functions
static Fl_X* first;
static Fl_X* i(const Fl_Window* w) {return (Fl_X*)w->i;}
static Fl_X* i(const Fl_Window* w) {return w ? (Fl_X*)w->i : 0;}
# if defined(FLTK_USE_X11) && FLTK_USE_X11 // for backward compatibility
static void make_xid(Fl_Window*, XVisualInfo* =fl_visual, Colormap=fl_colormap);
static Fl_X* set_xid(Fl_Window*, Window);

View File

@ -980,6 +980,7 @@ Fl_X *Fl_Wayland_Window_Driver::makeWindow()
Fl_Wayland_Screen_Driver::output *output;
wait_for_expose_value = 1;
if (pWindow->parent() && !pWindow->window()) return NULL;
if (pWindow->parent() && !pWindow->window()->shown()) return NULL;
new_window = (struct wld_window *)calloc(1, sizeof *new_window);