try harder to have --showpaths succeed

This helps avoid a potential chicken-and-egg scenario
with the system configuration file (sysconf).

If sysconf wasn't accessible at the expected location, it
caused an immediate exit, without relaying any helpful
information. That happened even when using:
    'nethack --showpaths'

That's particularly unhelpful, because the --showpaths
output might have been useful towards understanding where
NetHack was looking for such things.

That left you without an easy recourse to identify where
the game is looking for the sysconf file. That might be
especially troublesome if you didn't build the game
yourself.

include/decl.h

@@ -340,6 +340,10 @@ struct instance_globals_d {
     boolean decor_fumble_override;
     boolean decor_levitate_override;
 
+    /* new */
+    boolean deferred_showpaths;
+    const char *deferred_showpaths_dir;
+
     boolean havestate;
     unsigned long magic; /* validate that structure layout is preserved */
 };

include/extern.h

@@ -1072,11 +1072,12 @@ extern int nhclose(int);
 #ifdef DEBUG
 extern boolean debugcore(const char *, boolean);
 #endif
-extern void reveal_paths(void);
+extern void reveal_paths(int);
 extern boolean read_tribute(const char *, const char *, int, char *, int,
                             unsigned);
 extern boolean Death_quote(char *, int) NONNULLARG1;
 extern void livelog_add(long ll_type, const char *) NONNULLARG2;
+ATTRNORETURN extern void do_deferred_showpaths(int) NORETURN;
 
 /* ### fountain.c ### */
 
@@ -3379,6 +3380,7 @@ extern void append_slash(char *) NONNULLARG1;
 extern boolean check_user_string(const char *) NONNULLARG1;
 extern char *get_login_name(void);
 extern unsigned long sys_random_seed(void);
+ATTRNORETURN extern void after_opt_showpaths(const char *) NORETURN;
 #endif /* UNIX */
 
 /* ### unixtty.c ### */

src/decl.c

@@ -339,6 +339,8 @@ static const struct instance_globals_d g_init_d = {
     /* pickup.c */
     FALSE, /* decor_fumble_override */
     FALSE, /* decor_levitate_override */
+    FALSE, /* deferred_showpaths */
+    NULL,  /* deferred_showpaths_dir  */
     TRUE, /* havestate*/
     IVMAGIC  /* d_magic to validate that structure layout has been preserved */
 };

src/files.c

@@ -4467,6 +4467,8 @@ assure_syscf_file(void)
         close(fd);
         return;
     }
+    if (gd.deferred_showpaths)
+        do_deferred_showpaths(1);  /* does not return */
     raw_printf("Unable to open SYSCF_FILE.\n");
     exit(EXIT_FAILURE);
 }
@@ -4474,6 +4476,26 @@ assure_syscf_file(void)
 #endif /* SYSCF_FILE */
 #endif /* SYSCF */
 
+ATTRNORETURN void
+do_deferred_showpaths(int code)
+{
+    gd.deferred_showpaths = FALSE;
+    reveal_paths(code);
+
+#ifdef UNIX
+    after_opt_showpaths(gd.deferred_showpaths_dir);
+#else
+#ifdef CHDIR
+    chdirx(gd.deferred_showpaths_dir, 0);
+#endif
+#if defined(WIN32) || defined(MICRO) || defined(OS2)
+    nethack_exit(EXIT_SUCCESS);
+#else
+    exit(EXIT_SUCCESS);
+#endif
+#endif
+}
+
 #ifdef DEBUG
 /* used by debugpline() to decide whether to issue a message
  * from a particular source file; caller passes __FILE__ and we check
@@ -4534,9 +4556,11 @@ debugcore(const char *filename, boolean wildcards)
 #endif
 
 void
-reveal_paths(void)
+reveal_paths(int code)
 {
-    const char *fqn, *nodumpreason;
+    const char *fqn, *nodumpreason,
+	  *sysconffile = "system configuration file";
+
     char buf[BUFSZ];
 #if defined(SYSCF) || !defined(UNIX) || defined(DLB)
     const char *filep;
@@ -4570,7 +4594,8 @@ reveal_paths(void)
 #else
     buf[0] = '\0';
 #endif
-    raw_printf("%s system configuration file%s:", s_suffix(gamename), buf);
+    raw_printf("%s %s%s:",
+               s_suffix(gamename), sysconffile, buf);
 #ifdef SYSCF_FILE
     filep = SYSCF_FILE;
 #else
@@ -4582,6 +4607,10 @@ reveal_paths(void)
         filep = configfile;
     }
     raw_printf("    \"%s\"", filep);
+    if (code == 1) {
+        raw_printf("NOTE: The %s above is missing or inaccessible!",
+                   sysconffile);
+    }
 #else /* !SYSCF */
     raw_printf("No system configuration file.");
 #endif /* ?SYSCF */

src/options.c

@@ -6942,6 +6942,11 @@ initoptions(void)
      */
 #endif
 #endif /* SYSCF */
+
+    /* Carry out options that got deferred from early_options */
+    if (gd.deferred_showpaths)
+        do_deferred_showpaths(0);  /* does not return */
+
     initoptions_finish();
 }
 

sys/libnh/libnhmain.c

@@ -108,14 +108,8 @@ nhmain(int argc, char *argv[])
 #endif
 
         if (argcheck(argc, argv, ARG_SHOWPATHS) == 2) {
-#ifdef CHDIR
-            chdirx((char *) 0, 0);
-#endif
-            iflags.initoptions_noterminate = TRUE;
-            initoptions();
-            iflags.initoptions_noterminate = FALSE;
-            reveal_paths();
-            exit(EXIT_SUCCESS);
+            gd.deferred_showpaths = TRUE;
+            return;
         }
         if (argcheck(argc, argv, ARG_DEBUG) == 1) {
             argc--;

sys/unix/unixmain.c

@@ -36,7 +36,6 @@ static void consume_two_args(int, int *, char ***);
 static void early_options(int *, char ***, char **);
 ATTRNORETURN static void opt_terminate(void) NORETURN;
 ATTRNORETURN static void opt_usage(const char *) NORETURN;
-static void opt_showpaths(const char *);
 ATTRNORETURN static void scores_only(int, char **, const char *) NORETURN;
 #ifdef SND_LIB_INTEGRATED
 uint32_t soundlibchoice = soundlib_nosound;
@@ -702,9 +701,10 @@ early_options(int *argc_p, char ***argv_p, char **hackdir_p)
             break;
         case 's':
             if (argcheck(argc, argv, ARG_SHOWPATHS) == 2) {
-                opt_showpaths(*hackdir_p);
-                opt_terminate();
-                /*NOTREACHED*/
+		gd.deferred_showpaths = TRUE;
+		gd.deferred_showpaths_dir = *hackdir_p;
+                config_error_done();
+		return;
             }
             /* check for "-s" request to show scores */
             if (lopt(arg, ((ArgValDisallowed | ArgErrComplain)
@@ -785,18 +785,16 @@ opt_usage(const char *hackdir)
 
 /* show the sysconf file name, playground directory, run-time configuration
    file name, dumplog file name if applicable, and some other things */
-static void
-opt_showpaths(const char *dir)
+ATTRNORETURN void
+after_opt_showpaths(const char *dir)
 {
 #ifdef CHDIR
     chdirx(dir, FALSE);
 #else
     nhUse(dir);
 #endif
-    iflags.initoptions_noterminate = TRUE;
-    initoptions();
-    iflags.initoptions_noterminate = FALSE;
-    reveal_paths();
+    opt_terminate();
+    /*NOTREACHED*/
 }
 
 /* handle "-s <score options> [character-names]" to show all the entries

sys/vms/vmsmain.c

@@ -80,15 +80,9 @@ main(int argc, char *argv[])
             exit(EXIT_SUCCESS);
 
         if (argcheck(argc, argv, ARG_SHOWPATHS) == 2) {
-#ifdef CHDIR
-            chdirx((char *) 0, 0);
-#endif
-            iflags.initoptions_noterminate = TRUE;
-            initoptions();
-            iflags.initoptions_noterminate = FALSE;
-            reveal_paths();
-            exit(EXIT_SUCCESS);
-        }
+            gd.deferred_showpaths = TRUE;
+            return;
+	}
         if (argcheck(argc, argv, ARG_DEBUG) == 1) {
             argc--;
             argv++;

sys/windows/windmain.c

@@ -18,9 +18,9 @@
 #error You must #define SAFEPROCS to build windmain.c
 #endif
 
-static void process_options(int argc, char **argv);
 static void nhusage(void);
 static char *get_executable_path(void);
+static void early_options(int argc, char **argv);
 char *translate_path_variables(const char *, char *);
 char *exename(void);
 boolean fakeconsole(void);
@@ -242,6 +242,7 @@ _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);*/
     iflags.windowtype_deferred = TRUE;
     copy_sysconf_content();
     copy_symbols_content();
+    early_options(argc, argv);
     initoptions();
 
     /* Now that sysconf has had a chance to set the TROUBLEPREFIX, don't
@@ -249,7 +250,6 @@ _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);*/
     fqn_prefix_locked[TROUBLEPREFIX] = TRUE;
 
     copy_config_content();
-    process_options(argc, argv);
 
     /* did something earlier flag a need to exit without starting a game? */
     if (windows_startup_state > 0) {
@@ -462,23 +462,18 @@ attempt_restore:
 RESTORE_WARNING_UNREACHABLE_CODE
 
 static void
-process_options(int argc, char * argv[])
+early_options(int argc, char *argv[])
 {
     int i;
 
-    /*
-     * Process options.
-     */
     if (argc > 1) {
         if (argcheck(argc, argv, ARG_VERSION) == 2)
             nethack_exit(EXIT_SUCCESS);
 
         if (argcheck(argc, argv, ARG_SHOWPATHS) == 2) {
-            iflags.initoptions_noterminate = TRUE;
-            initoptions();
-            iflags.initoptions_noterminate = FALSE;
-            reveal_paths();
-            nethack_exit(EXIT_SUCCESS);
+            gd.deferred_showpaths = TRUE;
+            /* gd.deferred_showpaths is not used by windows */
+            return;
         }
 #ifndef NODUMPENUMS
         if (argcheck(argc, argv, ARG_DUMPENUMS) == 2) {
@@ -509,7 +504,7 @@ process_options(int argc, char * argv[])
              */
             argc--;
             argv++;
-            const char * dir = argv[0] + 2;
+            const char *dir = argv[0] + 2;
             if (*dir == '=' || *dir == ':')
                 dir++;
             if (!*dir && argc > 1) {
@@ -578,7 +573,8 @@ process_options(int argc, char * argv[])
 #endif
         case 'u':
             if (argv[0][2])
-                (void) strncpy(svp.plname, argv[0] + 2, sizeof(svp.plname) - 1);
+                (void) strncpy(svp.plname, argv[0] + 2,
+                               sizeof(svp.plname) - 1);
             else if (argc > 1) {
                 argc--;
                 argv++;
@@ -634,8 +630,8 @@ process_options(int argc, char * argv[])
                 break;
             } else
                 raw_printf("\nUnknown switch: %s", argv[0]);
-        FALLTHROUGH;
-	/* FALLTHRU */
+            FALLTHROUGH;
+        /* FALLTHRU */
         case '?':
             nhusage();
             nethack_exit(EXIT_SUCCESS);