memory management for 'nomakedefs'

The nomakedefs struct starts out with static values, then if/when
populate_nomakedefs() is called, the fields are given dynamic values.
free_nomakedefs() needs to know what state it's in.

A big chunk of this if just formatting for indentation.

src/date.c

@@ -1,4 +1,4 @@
-/* NetHack 3.7  date.c  $NHDT-Date: 1644524054 2022/02/10 20:14:14 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.1 $ */
+/* NetHack 3.7  date.c  $NHDT-Date: 1645393645 2022/02/20 21:47:25 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.2 $ */
 /* Copyright (c) Michael Allison, 2021.                           */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -17,6 +17,9 @@ extern char *version_id_string(char *, int, const char *);
 extern char *bannerc_string(char *, int, const char *);
 extern int case_insensitive_comp(const char *, const char *);
 
+/* nomakedefs_populated: flag for whether 'nomakedefs' should be freed */
+static int nomakedefs_populated = 0;
+
 struct nomakedefs_s nomakedefs = {
     /* https://groups.google.com/forum/#!original/
        comp.sources.games/91SfKYg_xzI/dGnR3JnspFkJ */
@@ -54,6 +57,7 @@ populate_nomakedefs(struct version_info *version)
         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};
     struct tm t = {0};
     time_t timeresult;
+
     /*
      * In a cross-compiled environment, you can't execute
      * the target binaries during the build, so we can't
@@ -73,8 +77,7 @@ populate_nomakedefs(struct version_info *version)
      *    gcc, msvc, clang   __TIME__  "23:59:01"
      *
      */
-        /* if (sizeof __DATE__ + sizeof __TIME__  + sizeof "123" <
+
-            sizeof tmpbuf1) */
     Snprintf(tmpbuf1, sizeof tmpbuf1, "%s %s", __DATE__, __TIME__);
     /* "Feb 12 1996 23:59:01"
         01234567890123456789  */
@@ -122,11 +125,20 @@ populate_nomakedefs(struct version_info *version)
 #ifdef NETHACK_GIT_BRANCH
     nomakedefs.git_branch = dupstr(NETHACK_GIT_BRANCH);
 #endif
+
+    nomakedefs_populated = 1;
+    return;
 }
 
 void
 free_nomakedefs(void)
 {
+    /* can't just free non-Null values because they're initialized at
+       compile-time with static strings and won't have dynamic values
+       unless populate_nomakedefs() has been called */
+    if (!nomakedefs_populated)
+        return;
+
     if (nomakedefs.build_date)
         free((genericptr_t) nomakedefs.build_date),
             nomakedefs.build_date = 0;
@@ -149,6 +161,10 @@ free_nomakedefs(void)
         free((genericptr_t) nomakedefs.git_branch),
             nomakedefs.git_branch = 0;
 #endif
+
+    /* values are Null now; dynamic vs static doesn't really matter anymore */
+    nomakedefs_populated = 0;
+    return;
 }
 
 #endif /* __DATE__ && __TIME__ */