fixed crash bug with alt-tab + run-dialog (or internal windows in general)

ChangeLog

@@ -1,3 +1,7 @@
+Changes since version 0.91.0:
+.............................
+- fixed crash with info panel and alt-tabbing
+
 Changes since version 0.90.0:
 .............................
 

src/switchpanel.c

@@ -360,9 +360,13 @@ drawTitle(WSwitchPanel *panel, int index, char *title)
     int width= WMWidgetWidth(panel->win);
     int x;
 
+    if (title)
         ntitle= ShrinkString(panel->font, title, width-2*BORDER_SPACE);
+    else
+        ntitle= NULL;
 
     if (panel->bg) {
+        if (ntitle) {
             if (strcmp(ntitle, title)!=0)
               x= BORDER_SPACE;
             else
@@ -375,16 +379,19 @@ drawTitle(WSwitchPanel *panel, int index, char *title)
                 else if (x + w > width-BORDER_SPACE)
                     x= width-BORDER_SPACE-w;
             }
-        
+        }       
         XClearWindow(dpy, WMWidgetXID(panel->win));
+        if (ntitle)
             WMDrawString(panel->scr->wmscreen, 
                          WMWidgetXID(panel->win),
                          panel->white, panel->font,
                          x, WMWidgetHeight(panel->win) - BORDER_SPACE - LABEL_HEIGHT + WMFontHeight(panel->font)/2,
                          ntitle, strlen(ntitle));
     } else {
+        if (ntitle)
             WMSetLabelText(panel->label, ntitle);
     }
+    if (ntitle)
         free(ntitle);
 }