fix NULL pointer dereferences and implement some additional safeguards

ok marco

diff --git a/scrotwm.c b/scrotwm.c
index f03445b..9f7ea21 100644 (file)
--- a/scrotwm.c
+++ b/scrotwm.c
@@ -3353,10 +3353,13 @@ resize(struct ws_win *win, union arg *args)
 {
        XEvent                  ev;
        Time                    time = 0;
-       struct swm_region       *r = win->ws->r;
+       struct swm_region       *r = NULL;
        int                     relx, rely;
        int                     resize_step = 0;
 
+       if (win == NULL)
+               return;
+       r = win->ws->r;
 
        DNPRINTF(SWM_D_MOUSE, "resize: win %lu floating %d trans %lu\n",
            win->id, win->floating, win->transient);
@@ -3471,7 +3474,7 @@ resize_step(struct swm_region *r, union arg *args)
 {
        struct ws_win           *win = NULL;
 
-       if (r && r->ws)
+       if (r && r->ws && r->ws->focus)
                win = r->ws->focus;
        else
                return;
@@ -3508,7 +3511,11 @@ move(struct ws_win *win, union arg *args)
        XEvent                  ev;
        Time                    time = 0;
        int                     move_step = 0;
-       struct swm_region       *r = win->ws->r;
+       struct swm_region       *r = NULL;
+
+       if (win == NULL)
+               return;
+       r = win->ws->r;
 
        DNPRINTF(SWM_D_MOUSE, "move: win %lu floating %d trans %lu\n",
            win->id, win->floating, win->transient);
@@ -3605,7 +3612,7 @@ move_step(struct swm_region *r, union arg *args)
 {
        struct ws_win           *win = NULL;
 
-       if (r && r->ws)
+       if (r && r->ws && r->ws->focus)
                win = r->ws->focus;
        else
                return;