Fuzz testing debug tool

Add code to run a fuzz tester, simulating (more-or-less) random
keyboard mashing. There's no option to turn it on, you need to
set iflags.debug_fuzzer on via a debugger or something along
those lines.

src/allmain.c

@@ -389,7 +389,7 @@ boolean resuming;
             continue;
         }
 
-        if (iflags.sanity_check)
+        if (iflags.sanity_check || iflags.debug_fuzzer)
             sanity_check();
 
 #ifdef CLIPPING

src/cmd.c

@@ -298,6 +298,8 @@ pgetchar() /* courtesy of aeb@cwi.nl */
 {
     register int ch;
 
+    if (iflags.debug_fuzzer)
+        return randomkey();
     if (!(ch = popch()))
         ch = nhgetch();
     return (char) ch;
@@ -942,6 +944,11 @@ wiz_level_change(VOID_ARGS)
 STATIC_PTR int
 wiz_panic(VOID_ARGS)
 {
+    if (iflags.debug_fuzzer) {
+        u.uhp = u.uhpmax = 1000;
+        u.uen = u.uenmax = 1000;
+        return 0;
+    }
     if (yn("Do you want to call panic() and end your game?") == 'y')
         panic("Crash test.");
     return 0;
@@ -4354,6 +4361,29 @@ int NDECL((*cmd_func));
     return FALSE;
 }
 
+char
+randomkey()
+{
+    static int i = 0;
+    char c;
+
+    switch (rn2(12)) {
+    default: c = '\033'; break;
+    case 0: c = '\n'; break;
+    case 1:
+    case 2:
+    case 3:
+    case 4: c = (char)(' ' + rn2((int)('~' - ' '))); break;
+    case 5: c = '\t'; break;
+    case 6: c = (char)('a' + rn2((int)('z' - 'a'))); break;
+    case 7: c = (char)('A' + rn2((int)('Z' - 'A'))); break;
+    case 8: c = extcmdlist[(i++) % SIZE(extcmdlist)].key; break;
+    case 9: c = '#'; break;
+    }
+
+    return c;
+}
+
 int
 ch2spkeys(c, start, end)
 char c;
@@ -5563,6 +5593,8 @@ readchar()
     register int sym;
     int x = u.ux, y = u.uy, mod = 0;
 
+    if (iflags.debug_fuzzer)
+        return randomkey();
     if (*readchar_queue)
         sym = *readchar_queue++;
     else

src/do.c

@@ -1061,6 +1061,8 @@ doup()
         return 1;
     }
     if (ledger_no(&u.uz) == 1) {
+        if (iflags.debug_fuzzer)
+            return 0;
         if (yn("Beware, there will be no return! Still climb?") != 'y')
             return 0;
     }

src/end.c

@@ -330,6 +330,8 @@ int sig_unused UNUSED;
 int
 done2()
 {
+    if (iflags.debug_fuzzer)
+        return 0;
     if (!paranoid_query(ParanoidQuit, "Really quit?")) {
 #ifndef NO_SIGNAL
         (void) signal(SIGINT, (SIG_RET_TYPE) done1);
@@ -602,7 +604,7 @@ VA_DECL(const char *, str)
     /* XXX can we move this above the prints?  Then we'd be able to
      * suppress "it may be possible to rebuild" based on dosave0()
      * or say it's NOT possible to rebuild. */
-    if (program_state.something_worth_saving) {
+    if (program_state.something_worth_saving && !iflags.debug_fuzzer) {
         set_error_savefile();
         if (dosave0()) {
             /* os/win port specific recover instructions */
@@ -1043,6 +1045,14 @@ int how;
         bot();
     }
 
+    if (iflags.debug_fuzzer) {
+        if (!(program_state.panicking || how == PANICKED)) {
+            savelife(how);
+            killer.name[0] = 0;
+            killer.format = 0;
+            return;
+        }
+    } else
     if (how == ASCENDED || (!killer.name[0] && how == GENOCIDED))
         killer.format = NO_KILLER_PREFIX;
     /* Avoid killed by "a" burning or "a" starvation */

src/mail.c

@@ -642,6 +642,8 @@ struct obj *otmp UNUSED;
     return;
 #endif /* SIMPLE_MAIL */
 #ifdef DEF_MAILREADER /* This implies that UNIX is defined */
+    if (iflags.debug_fuzzer)
+        return;
     display_nhwindow(WIN_MESSAGE, FALSE);
     if (!(mr = nh_getenv("MAILREADER")))
         mr = DEF_MAILREADER;
@@ -674,6 +676,8 @@ ckmailstatus()
 {
     struct mail_info *brdcst;
 
+    if (iflags.debug_fuzzer)
+        return;
     if (u.uswallow || !flags.biff)
         return;
 

src/pline.c

@@ -453,6 +453,8 @@ VA_DECL(const char *, s)
     Vsprintf(pbuf, s, VA_ARGS);
     pbuf[BUFSZ - 1] = '\0'; /* sanity */
     paniclog("impossible", pbuf);
+    if (iflags.debug_fuzzer)
+        panic(pbuf);
     pline("%s", VA_PASS1(pbuf));
     pline(VA_PASS1(
        "Program in disorder!  (Saving and reloading may fix this problem.)"));

src/save.c

@@ -77,6 +77,8 @@ static unsigned ustuck_id = 0, usteed_id = 0;
 int
 dosave()
 {
+    if (iflags.debug_fuzzer)
+        return 0;
     clear_nhwindow(WIN_MESSAGE);
     if (yn("Really save?") == 'n') {
         clear_nhwindow(WIN_MESSAGE);

src/teleport.c

@@ -608,6 +608,8 @@ level_tele()
     char buf[BUFSZ];
     boolean force_dest = FALSE;
 
+    if (iflags.debug_fuzzer)
+        goto random_levtport;
     if ((u.uhave.amulet || In_endgame(&u.uz) || In_sokoban(&u.uz))
         && !wizard) {
         You_feel("very disoriented for a moment.");
@@ -750,6 +752,8 @@ level_tele()
 
     killer.name[0] = 0; /* still alive, so far... */
 
+    if (iflags.debug_fuzzer && newlev < 0)
+        goto random_levtport;
     if (newlev < 0 && !force_dest) {
         if (*u.ushops0) {
             /* take unpaid inventory items off of shop bills */