curses static analyzer bits

This is mostly just adding some Null guards ahead of
code that was already dereferencing pointers, so there
should be no change in behavior.

Also adds one validation of an array index that was
drawing a complaint.

win/curses/cursdial.c

@@ -1078,16 +1078,16 @@ menu_win_size(nhmenu *menu)
 
     /* Possibly reduce height if only 1 page */
     if (!menu_is_multipage(menu, maxwidth, maxheight)) {
-        menu_item_ptr = menu->entries;
+        if ((menu_item_ptr = menu->entries) != 0) {
+            while (menu_item_ptr->next_item != NULL) {
+                menu_item_ptr = menu_item_ptr->next_item;
+            }
 
-        while (menu_item_ptr->next_item != NULL) {
-            menu_item_ptr = menu_item_ptr->next_item;
-        }
+            lastline = (menu_item_ptr->line_num) + menu_item_ptr->num_lines;
 
-        lastline = (menu_item_ptr->line_num) + menu_item_ptr->num_lines;
-
-        if (lastline < maxheight) {
-            maxheight = lastline;
+            if (lastline < maxheight) {
+                maxheight = lastline;
+            }
         }
     }
 

win/curses/cursmesg.c

@@ -947,8 +947,8 @@ mesg_add_line(const char *mline)
         ++num_messages;
     } else {
         /* at capacity; old head is being removed */
-        first_mesg = first_mesg->next_mesg; /* new head */
-        first_mesg->prev_mesg = NULL; /* head has no prev_mesg */
+        if ((first_mesg = first_mesg->next_mesg) != 0) /* new head */
+            first_mesg->prev_mesg = NULL; /* head has no prev_mesg */
     }
     /* since 'current_mesg' might be reusing 'first_mesg' and has now
        become 'last_mesg', this update must be after head replacement */
@@ -1056,7 +1056,8 @@ curses_putmsghistory(const char *msg, boolean restoring_msghist)
            however, we aren't only called when restoring history;
            core uses putmsghistory() for other stuff during play
            and those messages should have a normal turn value */
-        last_mesg->turn = restoring_msghist ? (1L << 3) : gh.hero_seq;
+        if (last_mesg) /* appease static analyzer */
+            last_mesg->turn = restoring_msghist ? (1L << 3) : gh.hero_seq;
 #ifdef DUMPLOG
         dumplogmsg(last_mesg->str);
 #endif
@@ -1072,18 +1073,20 @@ curses_putmsghistory(const char *msg, boolean restoring_msghist)
                stashed messages as newly occurring ones is much simpler;
                we ignore the backlinks because the list is destroyed as it
                gets processed hence there can't be any other traversals */
-            mesg = stash_head;
-            stash_head = mesg->next_mesg;
-            --stash_count;
-            mesg_turn = mesg->turn;
-            mesg_add_line(mesg->str);
-            /* added line became new tail */
-            last_mesg->turn = mesg_turn;
+            if ((mesg = stash_head) != 0) {
+                stash_head = mesg->next_mesg;
+                --stash_count;
+                mesg_turn = mesg->turn;
+                mesg_add_line(mesg->str);
+                /* added line became new tail */
+                if (last_mesg) /* appease static analyzer */
+                    last_mesg->turn = mesg_turn;
 #ifdef DUMPLOG
-            dumplogmsg(mesg->str);
+                dumplogmsg(mesg->str);
 #endif
-            free((genericptr_t) mesg->str);
-            free((genericptr_t) mesg);
+                free((genericptr_t) mesg->str);
+                free((genericptr_t) mesg);
+            }
         }
         initd = FALSE; /* reset */
     }

win/curses/cursmisc.c

@@ -397,6 +397,7 @@ curses_str_remainder(const char *str, int width, int line_num)
         if (last_space == 0) {  /* No spaces found */
             last_space = count - 1;
         }
+        assert(IndexOk(last_space, substr));
         if (substr[last_space] == '\0') {
             break;
         }