maint: pacify -Wzero-as-null-pointer-constant

Recent Gnulib enables this warning, and it did find a bug
in GNU Tar, so pacify GCC everywhere else by preferring
NULL to 0 for pointers.

diff --git a/src/buffer.c b/src/buffer.c
index c7b4c6c0c811bcf36ac614882898f4ad5fc131fb..51be9e1aecff266232ff39bd847a9a3746613e11 100644 (file)
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -318,8 +318,8 @@ struct zip_program
 };
 
 static struct zip_magic const magic[] = {
-  { ct_none,     0, 0 },
-  { ct_tar,      0, 0 },
+  { ct_none,     0, NULL },
+  { ct_tar,      0, NULL },
   { ct_compress, 2, "\037\235" },
   { ct_gzip,     2, "\037\213" },
   { ct_bzip2,    3, "BZh" },
@@ -413,7 +413,7 @@ check_compressed_archive (bool *pshort)
   sfr = read_full_records;
   read_full_records = true; /* Suppress fatal error on reading a partial
                                record */
-  *pshort = find_next_block () == 0;
+  *pshort = !find_next_block ();
 
   /* Restore global values */
   read_full_records = sfr;
@@ -615,12 +615,12 @@ find_next_block (void)
   if (current_block == record_end)
     {
       if (hit_eof)
-        return 0;
+        return NULL;
       flush_archive ();
       if (current_block == record_end)
         {
           hit_eof = true;
-          return 0;
+          return NULL;
         }
     }
   return current_block;

diff --git a/src/checkpoint.c b/src/checkpoint.c
index 5b82e97dd54b189077aa9daf497df6c240c002ff..199fe78f35eac8e9f44a52e1dbda6c766cf5fa92 100644 (file)
--- a/src/checkpoint.c
+++ b/src/checkpoint.c
@@ -311,7 +311,7 @@ format_checkpoint_string (FILE *fp, intmax_t len,
 #if HAVE_STRUCT_TM_TM_GMTOFF && HAVE_STRUCT_TM_TM_ZONE
                /* struct tm has POSIX.1-2024 tm_gmtoff and tm_zone,
                   so nstrftime ignores tz and any tz value will do.  */
-               timezone_t tz = 0;
+               timezone_t tz = NULL;
 #else
                static timezone_t tz;
                if (tm && !tz)

diff --git a/src/create.c b/src/create.c
index 8d9c1a1854e89fb336f0b4de4ce8c421ab8cedff..a962ed759c38e2bef063aa57b4bb8c8f257b427f 100644 (file)
--- a/src/create.c
+++ b/src/create.c
@@ -245,7 +245,7 @@ to_chars_subst (bool negative, bool gnu_format, uintmax_t value, int valsize,
       paxwarn (0, _("value %s%ju out of %s range %jd..%ju;"
                    " substituting %s%ju"),
               valuesign, value, type, minval, maxval, ssign, s);
-      return to_chars (negsub, s, valsize, 0, where, size, type);
+      return to_chars (negsub, s, valsize, NULL, where, size, type);
     }
   else
     paxerror (0, _("value %s%ju out of %s range %jd..%ju"),
@@ -349,13 +349,13 @@ gid_to_chars (gid_t v, char *p, int s)
 static bool
 major_to_chars (major_t v, char *p, int s)
 {
-  return to_chars (v < 0, v, sizeof v, 0, p, s, "major_t");
+  return to_chars (v < 0, v, sizeof v, NULL, p, s, "major_t");
 }
 
 static bool
 minor_to_chars (minor_t v, char *p, int s)
 {
-  return to_chars (v < 0, v, sizeof v, 0, p, s, "minor_t");
+  return to_chars (v < 0, v, sizeof v, NULL, p, s, "minor_t");
 }
 
 static bool
@@ -395,19 +395,19 @@ mode_to_chars (mode_t v, char *p, int s)
           | (v & S_IWOTH ? TOWRITE : 0)
           | (v & S_IXOTH ? TOEXEC : 0));
     }
-  return to_chars (negative, u, sizeof v, 0, p, s, "mode_t");
+  return to_chars (negative, u, sizeof v, NULL, p, s, "mode_t");
 }
 
 bool
 off_to_chars (off_t v, char *p, int s)
 {
-  return to_chars (v < 0, v, sizeof v, 0, p, s, "off_t");
+  return to_chars (v < 0, v, sizeof v, NULL, p, s, "off_t");
 }
 
 bool
 time_to_chars (time_t v, char *p, int s)
 {
-  return to_chars (v < 0, v, sizeof v, 0, p, s, "time_t");
+  return to_chars (v < 0, v, sizeof v, NULL, p, s, "time_t");
 }
 
 static uintmax_t
@@ -1264,7 +1264,7 @@ get_directory_entries (struct tar_stat_info *st)
 {
   while (! (st->dirstream = fdopendir (st->fd)))
     if (! open_failure_recover (st))
-      return 0;
+      return NULL;
   return streamsavedir (st->dirstream, savedir_sort_order);
 }
 
@@ -1317,7 +1317,7 @@ create_archive (void)
 
       while ((p = name_from_list ()) != NULL)
        if (!excluded_name (p->name, NULL))
-         dump_file (0, p->name, p->name);
+         dump_file (NULL, p->name, p->name);
 
       blank_name_list ();
       while ((p = name_from_list ()) != NULL)
@@ -1377,7 +1377,7 @@ create_archive (void)
       const char *name;
       while ((name = name_next (true)))
        if (!excluded_name (name, NULL))
-         dump_file (0, name, name);
+         dump_file (NULL, name, name);
     }
 
   write_eot ();
@@ -1498,8 +1498,8 @@ file_count_links (struct tar_stat_info *st)
       free (linkname);
 
       if (! ((link_table
-             || (link_table = hash_initialize (0, 0, hash_link,
-                                               compare_links, 0)))
+             || (link_table = hash_initialize (0, NULL, hash_link,
+                                               compare_links, NULL)))
             && (duplicate = hash_insert (link_table, lp))))
        xalloc_die ();
 
@@ -1620,7 +1620,7 @@ dump_file0 (struct tar_stat_info *st, char const *name, char const *p)
   bool is_dir;
   struct tar_stat_info const *parent = st->parent;
   bool top_level = ! parent;
-  void (*diag) (char const *) = 0;
+  void (*diag) (char const *) = NULL;
 
   if (interactive_option && !confirm ("add", p))
     return NULL;

diff --git a/src/extract.c b/src/extract.c
index eaca4817a6558290e9597c13910c979b55e0b8ad..ab83a6508f7d636eaf57c2aac5927f4fa02c442d 100644 (file)
--- a/src/extract.c
+++ b/src/extract.c
@@ -565,7 +565,7 @@ delay_set_stat (char const *file_name, struct tar_stat_info const *st,
   struct delayed_set_stat *data;
 
   if (! (delayed_set_stat_table
-        || (delayed_set_stat_table = hash_initialize (0, 0, ds_hash,
+        || (delayed_set_stat_table = hash_initialize (0, NULL, ds_hash,
                                                       ds_compare, NULL))))
     xalloc_die ();
 
@@ -816,7 +816,7 @@ make_directories (char *file_name, bool *interdir_made)
             mode == desired_mode, because
             repair_delayed_set_stat may need to update the struct.  */
          delay_set_stat (file_name,
-                         0, mode & ~ current_umask, MODE_RWX,
+                         NULL, mode & ~ current_umask, MODE_RWX,
                          desired_mode, AT_SYMLINK_NOFOLLOW);
          if (interdir_made)
            *interdir_made = true;
@@ -915,7 +915,7 @@ maybe_recoverable (char *file_name, bool regular, bool *interdir_made)
 {
   int e = errno;
   struct stat st;
-  struct stat const *stp = 0;
+  struct stat const *stp = NULL;
 
   if (*interdir_made)
     return RECOVER_NO;
@@ -1539,7 +1539,7 @@ create_placeholder_file (char *file_name, bool is_symlink, bool *interdir_made)
       p->change_dir = chdir_current;
       p->sources = xmalloc (FLEXNSIZEOF (struct string_list, string,
                                         strlen (file_name) + 1));
-      p->sources->next = 0;
+      p->sources->next = NULL;
       strcpy (p->sources->string, file_name);
       p->cntx_name = NULL;
       assign_string_or_null (&p->cntx_name, current_stat_info.cntx_name);
@@ -1554,7 +1554,7 @@ create_placeholder_file (char *file_name, bool is_symlink, bool *interdir_made)
       *delayed_link_tail = p;
       delayed_link_tail = &p->next;
       if (! ((delayed_link_table
-             || (delayed_link_table = hash_initialize (0, 0, dl_hash,
+             || (delayed_link_table = hash_initialize (0, NULL, dl_hash,
                                                        dl_compare, free)))
             && hash_insert (delayed_link_table, p)))
        xalloc_die ();
@@ -1856,7 +1856,7 @@ prepare_to_extract (char const *file_name, char typeflag)
          break;
 
        case KEEP_NEWER_FILES:
-         if (file_newer_p (file_name, 0, &current_stat_info))
+         if (file_newer_p (file_name, NULL, &current_stat_info))
            {
              warnopt (WARN_IGNORE_NEWER, 0, _("Current %s is newer or same age"),
                       quote (file_name));

diff --git a/src/incremen.c b/src/incremen.c
index 27fbb7fb0d9ba3081e30668834ff5350b637f3c5..b7b0d1ccbf845cd2b0a28fca34d8c9d37d8b00c3 100644 (file)
--- a/src/incremen.c
+++ b/src/incremen.c
@@ -388,18 +388,18 @@ note_directory (char const *name, struct timespec mtime,
     directory->dump = NULL;
 
   if (! ((directory_table
-         || (directory_table = hash_initialize (0, 0,
+         || (directory_table = hash_initialize (0, NULL,
                                                 hash_directory_canonical_name,
                                                 compare_directory_canonical_names,
-                                                0)))
+                                                NULL)))
         && hash_insert (directory_table, directory)))
     xalloc_die ();
 
   if (! ((directory_meta_table
-         || (directory_meta_table = hash_initialize (0, 0,
+         || (directory_meta_table = hash_initialize (0, NULL,
                                                      hash_directory_meta,
                                                      compare_directory_meta,
-                                                     0)))
+                                                     NULL)))
         && hash_insert (directory_meta_table, directory)))
     xalloc_die ();
 
@@ -411,7 +411,7 @@ static struct directory *
 find_directory (const char *name)
 {
   if (! directory_table)
-    return 0;
+    return NULL;
   else
     {
       char *caname = normalize_filename (chdir_current, name);
@@ -452,7 +452,7 @@ static struct directory *
 find_directory_meta (dev_t dev, ino_t ino)
 {
   if (! directory_meta_table)
-    return 0;
+    return NULL;
   else
     {
       struct directory *dir = make_directory ("", NULL);
@@ -820,7 +820,7 @@ scan_directory (struct tar_stat_info *st)
              else
                {
                  int fd = st->fd;
-                 void (*diag) (char const *) = 0;
+                 void (*diag) (char const *) = NULL;
                  struct tar_stat_info stsub;
                  tar_stat_init (&stsub);
 

diff --git a/src/list.c b/src/list.c
index db074bc7c54ec9a56eb450f77d76910604455c36..d541cf267eca736a42e473b5c804af1e29541ebc 100644 (file)
--- a/src/list.c
+++ b/src/list.c
@@ -364,7 +364,7 @@ tar_checksum (union block *header, bool silent)
   signed_sum   += ' ' * sizeof header->header.chksum;
 
   int recorded_sum = from_header (header->header.chksum,
-                                 sizeof header->header.chksum, 0,
+                                 sizeof header->header.chksum, NULL,
                                  0, INT_MAX, true, silent);
   if (recorded_sum < 0)
     return HEADER_FAILURE;
@@ -552,7 +552,7 @@ read_header (union block **return_block, struct tar_stat_info *info,
              memcpy (np, h->name, sizeof h->name);
              np[sizeof h->name] = '\0';
              name = namebuf;
-             recent_long_name = 0;
+             recent_long_name = NULL;
              recent_long_name_blocks = 0;
            }
          assign_string (&info->orig_file_name, name);
@@ -573,7 +573,7 @@ read_header (union block **return_block, struct tar_stat_info *info,
              memcpy (namebuf, h->linkname, sizeof h->linkname);
              namebuf[sizeof h->linkname] = '\0';
              name = namebuf;
-             recent_long_link = 0;
+             recent_long_link = NULL;
              recent_long_link_blocks = 0;
            }
          assign_string (&info->link_name, name);
@@ -912,7 +912,7 @@ from_header (char const *where0, int digs, char const *type,
 
          if (!o)
            {
-             o = clone_quoting_options (0);
+             o = clone_quoting_options (NULL);
              set_quoting_style (o, locale_quoting_style);
            }
 

diff --git a/src/map.c b/src/map.c
index b1b2978676a94bf718917f5696ecab3c4314ba04..c484f8c6cb2aaf2cf22a539198855a35116f2c59 100644 (file)
--- a/src/map.c
+++ b/src/map.c
@@ -169,7 +169,8 @@ map_read (Hash_table **ptab, char const *file,
       ent->new_name = name ? xstrdup (name) : NULL;
 
       if (!((*ptab
-            || (*ptab = hash_initialize (0, 0, map_hash, map_compare, 0)))
+            || (*ptab = hash_initialize (0, NULL, map_hash, map_compare,
+                                         NULL)))
            && hash_insert (*ptab, ent)))
        xalloc_die ();
     }

diff --git a/src/names.c b/src/names.c
index 726b61ec90bcae673cb4cc84e4971321b9f0c72a..1b8131c5b439ddcf0f535ae6566c59ad34af77d4 100644 (file)
--- a/src/names.c
+++ b/src/names.c
@@ -82,31 +82,31 @@ static struct argp_option names_options[] = {
    N_("change to directory DIR"), GRID_LOCAL },
   {"files-from", 'T', N_("FILE"), 0,
    N_("get names to extract or create from FILE"), GRID_LOCAL },
-  {"null", NULL_OPTION, 0, 0,
+  {"null", NULL_OPTION, NULL, 0,
    N_("-T reads null-terminated names; implies --verbatim-files-from"),
       GRID_LOCAL },
-  {"no-null", NO_NULL_OPTION, 0, 0,
+  {"no-null", NO_NULL_OPTION, NULL, 0,
    N_("disable the effect of the previous --null option"), GRID_LOCAL },
-  {"unquote", UNQUOTE_OPTION, 0, 0,
+  {"unquote", UNQUOTE_OPTION, NULL, 0,
    N_("unquote input file or member names (default)"), GRID_LOCAL },
-  {"no-unquote", NO_UNQUOTE_OPTION, 0, 0,
+  {"no-unquote", NO_UNQUOTE_OPTION, NULL, 0,
    N_("do not unquote input file or member names"), GRID_LOCAL },
-  {"verbatim-files-from", VERBATIM_FILES_FROM_OPTION, 0, 0,
+  {"verbatim-files-from", VERBATIM_FILES_FROM_OPTION, NULL, 0,
    N_("-T reads file names verbatim (no escape or option handling)"), GRID_LOCAL },
-  {"no-verbatim-files-from", NO_VERBATIM_FILES_FROM_OPTION, 0, 0,
+  {"no-verbatim-files-from", NO_VERBATIM_FILES_FROM_OPTION, NULL, 0,
    N_("-T treats file names starting with dash as options (default)"),
       GRID_LOCAL },
   {"exclude", EXCLUDE_OPTION, N_("PATTERN"), 0,
    N_("exclude files, given as a PATTERN"), GRID_LOCAL },
   {"exclude-from", 'X', N_("FILE"), 0,
    N_("exclude patterns listed in FILE"), GRID_LOCAL },
-  {"exclude-caches", EXCLUDE_CACHES_OPTION, 0, 0,
+  {"exclude-caches", EXCLUDE_CACHES_OPTION, NULL, 0,
    N_("exclude contents of directories containing CACHEDIR.TAG, "
       "except for the tag file itself"), GRID_LOCAL },
-  {"exclude-caches-under", EXCLUDE_CACHES_UNDER_OPTION, 0, 0,
+  {"exclude-caches-under", EXCLUDE_CACHES_UNDER_OPTION, NULL, 0,
    N_("exclude everything under directories containing CACHEDIR.TAG"),
    GRID_LOCAL },
-  {"exclude-caches-all", EXCLUDE_CACHES_ALL_OPTION, 0, 0,
+  {"exclude-caches-all", EXCLUDE_CACHES_ALL_OPTION, NULL, 0,
    N_("exclude directories containing CACHEDIR.TAG"), GRID_LOCAL },
   {"exclude-tag", EXCLUDE_TAG_OPTION, N_("FILE"), 0,
    N_("exclude contents of directories containing FILE, except"
@@ -127,29 +127,29 @@ static struct argp_option names_options[] = {
    N_("read exclude patterns from the VCS ignore files"), GRID_LOCAL },
   {"exclude-backups", EXCLUDE_BACKUPS_OPTION, NULL, 0,
    N_("exclude backup and lock files"), GRID_LOCAL },
-  {"recursion", RECURSION_OPTION, 0, 0,
+  {"recursion", RECURSION_OPTION, NULL, 0,
    N_("recurse into directories (default)"), GRID_LOCAL },
-  {"no-recursion", NO_RECURSION_OPTION, 0, 0,
+  {"no-recursion", NO_RECURSION_OPTION, NULL, 0,
    N_("avoid descending automatically in directories"), GRID_LOCAL },
 
   {NULL, 0, NULL, 0,
    N_("File name matching options (affect both exclude and include patterns):"),
    GRH_MATCH },
-  {"anchored", ANCHORED_OPTION, 0, 0,
+  {"anchored", ANCHORED_OPTION, NULL, 0,
    N_("patterns match file name start"), GRID_MATCH },
-  {"no-anchored", NO_ANCHORED_OPTION, 0, 0,
+  {"no-anchored", NO_ANCHORED_OPTION, NULL, 0,
    N_("patterns match after any '/' (default for exclusion)"), GRID_MATCH },
-  {"ignore-case", IGNORE_CASE_OPTION, 0, 0,
+  {"ignore-case", IGNORE_CASE_OPTION, NULL, 0,
    N_("ignore case"), GRID_MATCH },
-  {"no-ignore-case", NO_IGNORE_CASE_OPTION, 0, 0,
+  {"no-ignore-case", NO_IGNORE_CASE_OPTION, NULL, 0,
    N_("case sensitive matching (default)"), GRID_MATCH },
-  {"wildcards", WILDCARDS_OPTION, 0, 0,
+  {"wildcards", WILDCARDS_OPTION, NULL, 0,
    N_("use wildcards (default for exclusion)"), GRID_MATCH },
-  {"no-wildcards", NO_WILDCARDS_OPTION, 0, 0,
+  {"no-wildcards", NO_WILDCARDS_OPTION, NULL, 0,
    N_("verbatim string matching"), GRID_MATCH },
-  {"wildcards-match-slash", WILDCARDS_MATCH_SLASH_OPTION, 0, 0,
+  {"wildcards-match-slash", WILDCARDS_MATCH_SLASH_OPTION, NULL, 0,
    N_("wildcards match '/' (default for exclusion)"), GRID_MATCH },
-  {"no-wildcards-match-slash", NO_WILDCARDS_MATCH_SLASH_OPTION, 0, 0,
+  {"no-wildcards-match-slash", NO_WILDCARDS_MATCH_SLASH_OPTION, NULL, 0,
    N_("wildcards do not match '/'"), GRID_MATCH },
 
   {NULL}
@@ -1188,7 +1188,7 @@ name_gather (void)
          free_name (buffer);
          buffer = make_name (ep->v.name);
          buffer->change_dir = change_dir;
-         buffer->next = 0;
+         buffer->next = NULL;
          buffer->found_count = 0;
          buffer->matching_flags = include_options ();
          buffer->directory = NULL;
@@ -1829,7 +1829,7 @@ collect_and_sort_names (void)
   namelist = merge_sort (namelist, num_names, compare_names);
 
   num_names = 0;
-  nametab = hash_initialize (0, 0, name_hash, name_compare, NULL);
+  nametab = hash_initialize (0, NULL, name_hash, name_compare, NULL);
   for (name = namelist; name; name = next_name)
     {
       next_name = name->next;
@@ -1905,10 +1905,10 @@ name_scan (const char *file_name, bool exact)
        {
          name_gather ();       /* read one more */
          if (namelist->found_count)
-           return 0;
+           return NULL;
        }
       else
-       return 0;
+       return NULL;
     }
 }
 
@@ -1942,7 +1942,7 @@ blank_name_list (void)
 {
   struct name *name;
 
-  gnu_list_name = 0;
+  gnu_list_name = NULL;
   for (name = namelist; name; name = name->next)
     name->found_count = 0;
 }

diff --git a/src/tar.c b/src/tar.c
index 89cc82b306f14cc558b33a9c2b8f5c99ddecd320..9c53bdbd77f21e0815591deb4f5a3769c221a0c0 100644 (file)
--- a/src/tar.c
+++ b/src/tar.c
@@ -532,24 +532,24 @@ static struct argp_option options[] = {
   {NULL, 0, NULL, 0,
    N_("Main operation mode:"), GRH_COMMAND },
 
-  {"list", 't', 0, 0,
+  {"list", 't', NULL, 0,
    N_("list the contents of an archive"), GRID_COMMAND },
-  {"extract", 'x', 0, 0,
+  {"extract", 'x', NULL, 0,
    N_("extract files from an archive"), GRID_COMMAND },
-  {"get", 0, 0, OPTION_ALIAS, NULL, GRID_COMMAND },
-  {"create", 'c', 0, 0,
+  {"get", 0, NULL, OPTION_ALIAS, NULL, GRID_COMMAND },
+  {"create", 'c', NULL, 0,
    N_("create a new archive"), GRID_COMMAND },
-  {"diff", 'd', 0, 0,
+  {"diff", 'd', NULL, 0,
    N_("find differences between archive and file system"), GRID_COMMAND },
-  {"compare", 0, 0, OPTION_ALIAS, NULL, GRID_COMMAND },
-  {"append", 'r', 0, 0,
+  {"compare", 0, NULL, OPTION_ALIAS, NULL, GRID_COMMAND },
+  {"append", 'r', NULL, 0,
    N_("append files to the end of an archive"), GRID_COMMAND },
-  {"update", 'u', 0, 0,
+  {"update", 'u', NULL, 0,
    N_("only append files newer than copy in archive"), GRID_COMMAND },
-  {"catenate", 'A', 0, 0,
+  {"catenate", 'A', NULL, 0,
    N_("append tar files to an archive"), GRID_COMMAND },
-  {"concatenate", 0, 0, OPTION_ALIAS, NULL, GRID_COMMAND },
-  {"delete", DELETE_OPTION, 0, 0,
+  {"concatenate", 0, NULL, OPTION_ALIAS, NULL, GRID_COMMAND },
+  {"delete", DELETE_OPTION, NULL, 0,
    N_("delete from the archive (not on mag tapes!)"), GRID_COMMAND },
   {"test-label", TEST_LABEL_OPTION, NULL, 0,
    N_("test the archive volume label and exit"), GRID_COMMAND },
@@ -557,20 +557,20 @@ static struct argp_option options[] = {
   {NULL, 0, NULL, 0,
    N_("Operation modifiers:"), GRH_MODIFIER },
 
-  {"sparse", 'S', 0, 0,
+  {"sparse", 'S', NULL, 0,
    N_("handle sparse files efficiently"), GRID_MODIFIER },
   {"hole-detection", HOLE_DETECTION_OPTION, N_("TYPE"), 0,
    N_("technique to detect holes"), GRID_MODIFIER },
   {"sparse-version", SPARSE_VERSION_OPTION, N_("MAJOR[.MINOR]"), 0,
    N_("set version of the sparse format to use (implies --sparse)"),
    GRID_MODIFIER},
-  {"incremental", 'G', 0, 0,
+  {"incremental", 'G', NULL, 0,
    N_("handle old GNU-format incremental backup"), GRID_MODIFIER },
   {"listed-incremental", 'g', N_("FILE"), 0,
    N_("handle new GNU-format incremental backup"), GRID_MODIFIER },
   {"level", LEVEL_OPTION, N_("NUMBER"), 0,
    N_("dump level for created listed-incremental archive"), GRID_MODIFIER },
-  {"ignore-failed-read", IGNORE_FAILED_READ_OPTION, 0, 0,
+  {"ignore-failed-read", IGNORE_FAILED_READ_OPTION, NULL, 0,
    N_("do not exit with nonzero on unreadable files"), GRID_MODIFIER },
   {"occurrence", OCCURRENCE_OPTION, N_("NUMBER"), OPTION_ARG_OPTIONAL,
    N_("process only the NUMBERth occurrence of each file in the archive;"
@@ -592,30 +592,30 @@ static struct argp_option options[] = {
   {NULL, 0, NULL, 0,
    N_("Overwrite control:"), GRH_OVERWRITE },
 
-  {"verify", 'W', 0, 0,
+  {"verify", 'W', NULL, 0,
    N_("attempt to verify the archive after writing it"), GRID_OVERWRITE },
-  {"remove-files", REMOVE_FILES_OPTION, 0, 0,
+  {"remove-files", REMOVE_FILES_OPTION, NULL, 0,
    N_("remove files after adding them to the archive"), GRID_OVERWRITE },
-  {"keep-old-files", 'k', 0, 0,
+  {"keep-old-files", 'k', NULL, 0,
    N_("don't replace existing files when extracting, "
       "treat them as errors"), GRID_OVERWRITE },
-  {"skip-old-files", SKIP_OLD_FILES_OPTION, 0, 0,
+  {"skip-old-files", SKIP_OLD_FILES_OPTION, NULL, 0,
    N_("don't replace existing files when extracting, silently skip over them"),
    GRID_OVERWRITE },
-  {"keep-newer-files", KEEP_NEWER_FILES_OPTION, 0, 0,
+  {"keep-newer-files", KEEP_NEWER_FILES_OPTION, NULL, 0,
    N_("don't replace existing files that are newer than their archive copies"), GRID_OVERWRITE },
-  {"overwrite", OVERWRITE_OPTION, 0, 0,
+  {"overwrite", OVERWRITE_OPTION, NULL, 0,
    N_("overwrite existing files when extracting"), GRID_OVERWRITE },
-  {"unlink-first", 'U', 0, 0,
+  {"unlink-first", 'U', NULL, 0,
    N_("remove each file prior to extracting over it"), GRID_OVERWRITE },
-  {"recursive-unlink", RECURSIVE_UNLINK_OPTION, 0, 0,
+  {"recursive-unlink", RECURSIVE_UNLINK_OPTION, NULL, 0,
    N_("empty hierarchies prior to extracting directory"), GRID_OVERWRITE },
-  {"no-overwrite-dir", NO_OVERWRITE_DIR_OPTION, 0, 0,
+  {"no-overwrite-dir", NO_OVERWRITE_DIR_OPTION, NULL, 0,
    N_("preserve metadata of existing directories"), GRID_OVERWRITE },
-  {"overwrite-dir", OVERWRITE_DIR_OPTION, 0, 0,
+  {"overwrite-dir", OVERWRITE_DIR_OPTION, NULL, 0,
    N_("overwrite metadata of existing directories when extracting (default)"),
    GRID_OVERWRITE },
-  {"keep-directory-symlink", KEEP_DIRECTORY_SYMLINK_OPTION, 0, 0,
+  {"keep-directory-symlink", KEEP_DIRECTORY_SYMLINK_OPTION, NULL, 0,
    N_("preserve existing symlinks to directories when extracting"),
    GRID_OVERWRITE },
   {"one-top-level", ONE_TOP_LEVEL_OPTION, N_("DIR"), OPTION_ARG_OPTIONAL,
@@ -625,13 +625,13 @@ static struct argp_option options[] = {
   {NULL, 0, NULL, 0,
    N_("Select output stream:"), GRH_OUTPUT },
 
-  {"to-stdout", 'O', 0, 0,
+  {"to-stdout", 'O', NULL, 0,
    N_("extract files to standard output"), GRID_OUTPUT },
   {"to-command", TO_COMMAND_OPTION, N_("COMMAND"), 0,
    N_("pipe extracted files to another program"), GRID_OUTPUT },
-  {"ignore-command-error", IGNORE_COMMAND_ERROR_OPTION, 0, 0,
+  {"ignore-command-error", IGNORE_COMMAND_ERROR_OPTION, NULL, 0,
    N_("ignore exit codes of children"), GRID_OUTPUT },
-  {"no-ignore-command-error", NO_IGNORE_COMMAND_ERROR_OPTION, 0, 0,
+  {"no-ignore-command-error", NO_IGNORE_COMMAND_ERROR_OPTION, NULL, 0,
    N_("treat non-zero exit codes of children as error"), GRID_OUTPUT },
 
   {NULL, 0, NULL, 0,
@@ -647,7 +647,7 @@ static struct argp_option options[] = {
    N_("use FILE to map file owner GIDs and names"), GRID_FATTR },
   {"mtime", MTIME_OPTION, N_("DATE-OR-FILE"), 0,
    N_("set mtime for added files from DATE-OR-FILE"), GRID_FATTR },
-  {"clamp-mtime", CLAMP_MTIME_OPTION, 0, 0,
+  {"clamp-mtime", CLAMP_MTIME_OPTION, NULL, 0,
    N_("only set time when the file is more recent than what was given with --mtime"), GRID_FATTR },
   {"set-mtime-command", SET_MTIME_COMMAND_OPTION, N_("COMMAND"), 0,
    N_("use output of the COMMAND to set mtime of the stored archive members"),
@@ -661,28 +661,28 @@ static struct argp_option options[] = {
    N_("preserve access times on dumped files, either by restoring the times"
       " after reading (METHOD='replace'; default) or by not setting the times"
       " in the first place (METHOD='system')"), GRID_FATTR },
-  {"touch", 'm', 0, 0,
+  {"touch", 'm', NULL, 0,
    N_("don't extract file modified time"), GRID_FATTR },
-  {"same-owner", SAME_OWNER_OPTION, 0, 0,
+  {"same-owner", SAME_OWNER_OPTION, NULL, 0,
    N_("try extracting files with the same ownership as exists in the archive (default for superuser)"), GRID_FATTR },
-  {"no-same-owner", NO_SAME_OWNER_OPTION, 0, 0,
+  {"no-same-owner", NO_SAME_OWNER_OPTION, NULL, 0,
    N_("extract files as yourself (default for ordinary users)"), GRID_FATTR },
-  {"numeric-owner", NUMERIC_OWNER_OPTION, 0, 0,
+  {"numeric-owner", NUMERIC_OWNER_OPTION, NULL, 0,
    N_("always use numbers for user/group names"), GRID_FATTR },
-  {"preserve-permissions", 'p', 0, 0,
+  {"preserve-permissions", 'p', NULL, 0,
    N_("extract information about file permissions (default for superuser)"),
    GRID_FATTR },
-  {"same-permissions", 0, 0, OPTION_ALIAS, NULL, GRID_FATTR },
-  {"no-same-permissions", NO_SAME_PERMISSIONS_OPTION, 0, 0,
+  {"same-permissions", 0, NULL, OPTION_ALIAS, NULL, GRID_FATTR },
+  {"no-same-permissions", NO_SAME_PERMISSIONS_OPTION, NULL, 0,
    N_("apply the user's umask when extracting permissions from the archive (default for ordinary users)"), GRID_FATTR },
-  {"preserve-order", 's', 0, 0,
+  {"preserve-order", 's', NULL, 0,
    N_("member arguments are listed in the same order as the "
       "files in the archive"), GRID_FATTR },
-  {"same-order", 0, 0, OPTION_ALIAS, NULL, GRID_FATTR },
-  {"delay-directory-restore", DELAY_DIRECTORY_RESTORE_OPTION, 0, 0,
+  {"same-order", 0, NULL, OPTION_ALIAS, NULL, GRID_FATTR },
+  {"delay-directory-restore", DELAY_DIRECTORY_RESTORE_OPTION, NULL, 0,
    N_("delay setting modification times and permissions of extracted"
       " directories until the end of extraction"), GRID_FATTR },
-  {"no-delay-directory-restore", NO_DELAY_DIRECTORY_RESTORE_OPTION, 0, 0,
+  {"no-delay-directory-restore", NO_DELAY_DIRECTORY_RESTORE_OPTION, NULL, 0,
    N_("cancel the effect of --delay-directory-restore option"), GRID_FATTR },
   {"sort", SORT_OPTION, N_("ORDER"), 0,
 #if D_INO_IN_DIRENT
@@ -695,21 +695,21 @@ static struct argp_option options[] = {
   {NULL, 0, NULL, 0,
    N_("Handling of extended file attributes:"), GRH_XATTR },
 
-  {"xattrs", XATTR_OPTION, 0, 0,
+  {"xattrs", XATTR_OPTION, NULL, 0,
    N_("Enable extended attributes support"), GRID_XATTR },
-  {"no-xattrs", NO_XATTR_OPTION, 0, 0,
+  {"no-xattrs", NO_XATTR_OPTION, NULL, 0,
    N_("Disable extended attributes support"), GRID_XATTR },
   {"xattrs-include", XATTR_INCLUDE, N_("MASK"), 0,
    N_("specify the include pattern for xattr keys"), GRID_XATTR },
   {"xattrs-exclude", XATTR_EXCLUDE, N_("MASK"), 0,
    N_("specify the exclude pattern for xattr keys"), GRID_XATTR },
-  {"selinux", SELINUX_CONTEXT_OPTION, 0, 0,
+  {"selinux", SELINUX_CONTEXT_OPTION, NULL, 0,
    N_("Enable the SELinux context support"), GRID_XATTR },
-  {"no-selinux", NO_SELINUX_CONTEXT_OPTION, 0, 0,
+  {"no-selinux", NO_SELINUX_CONTEXT_OPTION, NULL, 0,
    N_("Disable the SELinux context support"), GRID_XATTR },
-  {"acls", ACLS_OPTION, 0, 0,
+  {"acls", ACLS_OPTION, NULL, 0,
    N_("Enable the POSIX ACLs support"), GRID_XATTR },
-  {"no-acls", NO_ACLS_OPTION, 0, 0,
+  {"no-acls", NO_ACLS_OPTION, NULL, 0,
    N_("Disable the POSIX ACLs support"), GRID_XATTR },
 
   {NULL, 0, NULL, 0,
@@ -733,7 +733,7 @@ static struct argp_option options[] = {
   {NULL, '8', NULL, OPTION_HIDDEN, NULL, GRID_DEVICE },
   {NULL, '9', NULL, OPTION_HIDDEN, NULL, GRID_DEVICE },
 
-  {"force-local", FORCE_LOCAL_OPTION, 0, 0,
+  {"force-local", FORCE_LOCAL_OPTION, NULL, 0,
    N_("archive file is local even if it has a colon"),
    GRID_DEVICE },
   {"rmt-command", RMT_COMMAND_OPTION, N_("COMMAND"), 0,
@@ -743,7 +743,7 @@ static struct argp_option options[] = {
    N_("use remote COMMAND instead of rsh"),
    GRID_DEVICE },
 
-  {"multi-volume", 'M', 0, 0,
+  {"multi-volume", 'M', NULL, 0,
    N_("create/list/extract multi-volume archive"),
    GRID_DEVICE },
   {"tape-length", 'L', N_("NUMBER"), 0,
@@ -752,7 +752,7 @@ static struct argp_option options[] = {
   {"info-script", 'F', N_("NAME"), 0,
    N_("run script at end of each tape (implies -M)"),
    GRID_DEVICE },
-  {"new-volume-script", 0, 0, OPTION_ALIAS, NULL, GRID_DEVICE },
+  {"new-volume-script", 0, NULL, OPTION_ALIAS, NULL, GRID_DEVICE },
   {"volno-file", VOLNO_FILE_OPTION, N_("FILE"), 0,
    N_("use/update the volume number in FILE"),
    GRID_DEVICE },
@@ -764,9 +764,9 @@ static struct argp_option options[] = {
    N_("BLOCKS x 512 bytes per record"), GRID_BLOCKING },
   {"record-size", RECORD_SIZE_OPTION, N_("NUMBER"), 0,
    N_("NUMBER of bytes per record, multiple of 512"), GRID_BLOCKING },
-  {"ignore-zeros", 'i', 0, 0,
+  {"ignore-zeros", 'i', NULL, 0,
    N_("ignore zeroed blocks in archive (means EOF)"), GRID_BLOCKING },
-  {"read-full-records", 'B', 0, 0,
+  {"read-full-records", 'B', NULL, 0,
    N_("reblock as we read (for 4.2BSD pipes)"), GRID_BLOCKING },
 
   {NULL, 0, NULL, 0,
@@ -789,10 +789,10 @@ static struct argp_option options[] = {
   {"  posix", 0, NULL, OPTION_DOC|OPTION_NO_TRANS, N_("same as pax"),
    GRDOC_FORMAT },
 
-  {"old-archive", OLD_ARCHIVE_OPTION, 0, 0, /* FIXME */
+  {"old-archive", OLD_ARCHIVE_OPTION, NULL, 0, /* FIXME */
    N_("same as --format=v7"), GRID_FORMAT_OPT },
-  {"portability", 0, 0, OPTION_ALIAS, NULL, GRID_FORMAT_OPT },
-  {"posix", POSIX_OPTION, 0, 0,
+  {"portability", 0, NULL, OPTION_ALIAS, NULL, GRID_FORMAT_OPT },
+  {"posix", POSIX_OPTION, NULL, 0,
    N_("same as --format=posix"), GRID_FORMAT_OPT },
   {"pax-option", PAX_OPTION, N_("keyword[[:]=value][,keyword[[:]=value]]..."), 0,
    N_("control pax keywords"), GRID_FORMAT_OPT },
@@ -802,37 +802,37 @@ static struct argp_option options[] = {
 
   {NULL, 0, NULL, 0,
    N_("Compression options:"), GRH_COMPRESS },
-  {"auto-compress", 'a', 0, 0,
+  {"auto-compress", 'a', NULL, 0,
    N_("use archive suffix to determine the compression program"),
    GRID_COMPRESS },
-  {"no-auto-compress", NO_AUTO_COMPRESS_OPTION, 0, 0,
+  {"no-auto-compress", NO_AUTO_COMPRESS_OPTION, NULL, 0,
    N_("do not use archive suffix to determine the compression program"),
    GRID_COMPRESS },
   {"use-compress-program", 'I', N_("PROG"), 0,
    N_("filter through PROG (must accept -d)"), GRID_COMPRESS },
   /* Note: docstrings for the options below are generated by tar_help_filter */
-  {"bzip2", 'j', 0, 0, NULL, GRID_COMPRESS },
-  {"gzip", 'z', 0, 0, NULL, GRID_COMPRESS },
-  {"gunzip", 0, 0, OPTION_ALIAS, NULL, GRID_COMPRESS },
-  {"ungzip", 0, 0, OPTION_ALIAS, NULL, GRID_COMPRESS },
-  {"compress", 'Z', 0, 0, NULL, GRID_COMPRESS },
-  {"uncompress", 0, 0, OPTION_ALIAS, NULL, GRID_COMPRESS },
-  {"lzip", LZIP_OPTION, 0, 0, NULL, GRID_COMPRESS },
-  {"lzma", LZMA_OPTION, 0, 0, NULL, GRID_COMPRESS },
-  {"lzop", LZOP_OPTION, 0, 0, NULL, GRID_COMPRESS },
-  {"xz", 'J', 0, 0, NULL, GRID_COMPRESS },
-  {"zstd", ZSTD_OPTION, 0, 0, NULL, GRID_COMPRESS },
+  {"bzip2", 'j', NULL, 0, NULL, GRID_COMPRESS },
+  {"gzip", 'z', NULL, 0, NULL, GRID_COMPRESS },
+  {"gunzip", 0, NULL, OPTION_ALIAS, NULL, GRID_COMPRESS },
+  {"ungzip", 0, NULL, OPTION_ALIAS, NULL, GRID_COMPRESS },
+  {"compress", 'Z', NULL, 0, NULL, GRID_COMPRESS },
+  {"uncompress", 0, NULL, OPTION_ALIAS, NULL, GRID_COMPRESS },
+  {"lzip", LZIP_OPTION, NULL, 0, NULL, GRID_COMPRESS },
+  {"lzma", LZMA_OPTION, NULL, 0, NULL, GRID_COMPRESS },
+  {"lzop", LZOP_OPTION, NULL, 0, NULL, GRID_COMPRESS },
+  {"xz", 'J', NULL, 0, NULL, GRID_COMPRESS },
+  {"zstd", ZSTD_OPTION, NULL, 0, NULL, GRID_COMPRESS },
 
   {NULL, 0, NULL, 0,
    N_("Local file selection:"), GRH_FILE },
-  {"one-file-system", ONE_FILE_SYSTEM_OPTION, 0, 0,
+  {"one-file-system", ONE_FILE_SYSTEM_OPTION, NULL, 0,
    N_("stay in local file system when creating archive"), GRID_FILE },
-  {"absolute-names", 'P', 0, 0,
+  {"absolute-names", 'P', NULL, 0,
    N_("don't strip leading '/'s from file names"), GRID_FILE },
-  {"dereference", 'h', 0, 0,
+  {"dereference", 'h', NULL, 0,
    N_("follow symlinks; archive and dump the files they point to"),
    GRID_FILE },
-  {"hard-dereference", HARD_DEREFERENCE_OPTION, 0, 0,
+  {"hard-dereference", HARD_DEREFERENCE_OPTION, NULL, 0,
    N_("follow hard links; archive and dump the files they refer to"),
    GRID_FILE },
   {"starting-file", 'K', N_("MEMBER-NAME"), 0,
@@ -840,7 +840,7 @@ static struct argp_option options[] = {
    GRID_FILE },
   {"newer", 'N', N_("DATE-OR-FILE"), 0,
    N_("only store files newer than DATE-OR-FILE"), GRID_FILE },
-  {"after-date", 0, 0, OPTION_ALIAS, NULL, GRID_FILE },
+  {"after-date", 0, NULL, OPTION_ALIAS, NULL, GRID_FILE },
   {"newer-mtime", NEWER_MTIME_OPTION, N_("DATE"), 0,
    N_("compare date and time when data changed only"), GRID_FILE },
   {"backup", BACKUP_OPTION, N_("CONTROL"), OPTION_ARG_OPTIONAL,
@@ -857,7 +857,7 @@ static struct argp_option options[] = {
   {"transform", TRANSFORM_OPTION, N_("EXPRESSION"), 0,
    N_("use sed replace EXPRESSION to transform file names"),
    GRID_NAME_XFORM },
-  {"xform", 0, 0, OPTION_ALIAS, NULL, GRID_NAME_XFORM },
+  {"xform", 0, NULL, OPTION_ALIAS, NULL, GRID_NAME_XFORM },
 
   {NULL, 0, NULL, 0,
    N_("Informative output:"), GRH_INFORMATIVE },
@@ -868,41 +868,41 @@ static struct argp_option options[] = {
   {"checkpoint-action", CHECKPOINT_ACTION_OPTION, N_("ACTION"), 0,
    N_("execute ACTION on each checkpoint"),
    GRID_INFORMATIVE },
-  {"check-links", 'l', 0, 0,
+  {"check-links", 'l', NULL, 0,
    N_("print a message if not all links are dumped"), GRID_INFORMATIVE },
   {"totals", TOTALS_OPTION, N_("SIGNAL"), OPTION_ARG_OPTIONAL,
    N_("print total bytes after processing the archive; "
       "with an argument - print total bytes when this SIGNAL is delivered; "
       "Allowed signals are: SIGHUP, SIGQUIT, SIGINT, SIGUSR1 and SIGUSR2; "
       "the names without SIG prefix are also accepted"), GRID_INFORMATIVE },
-  {"utc", UTC_OPTION, 0, 0,
+  {"utc", UTC_OPTION, NULL, 0,
    N_("print file modification times in UTC"), GRID_INFORMATIVE },
-  {"full-time", FULL_TIME_OPTION, 0, 0,
+  {"full-time", FULL_TIME_OPTION, NULL, 0,
    N_("print file time to its full resolution"), GRID_INFORMATIVE },
   {"index-file", INDEX_FILE_OPTION, N_("FILE"), 0,
    N_("send verbose output to FILE"), GRID_INFORMATIVE },
-  {"block-number", 'R', 0, 0,
+  {"block-number", 'R', NULL, 0,
    N_("show block number within archive with each message"), GRID_INFORMATIVE },
-  {"show-defaults", SHOW_DEFAULTS_OPTION, 0, 0,
+  {"show-defaults", SHOW_DEFAULTS_OPTION, NULL, 0,
    N_("show tar defaults"), GRID_INFORMATIVE },
-  {"show-snapshot-field-ranges", SHOW_SNAPSHOT_FIELD_RANGES_OPTION, 0, 0,
+  {"show-snapshot-field-ranges", SHOW_SNAPSHOT_FIELD_RANGES_OPTION, NULL, 0,
    N_("show valid ranges for snapshot-file fields"), GRID_INFORMATIVE },
-  {"show-omitted-dirs", SHOW_OMITTED_DIRS_OPTION, 0, 0,
+  {"show-omitted-dirs", SHOW_OMITTED_DIRS_OPTION, NULL, 0,
    N_("when listing or extracting, list each directory that does not match search criteria"), GRID_INFORMATIVE },
-  {"show-transformed-names", SHOW_TRANSFORMED_NAMES_OPTION, 0, 0,
+  {"show-transformed-names", SHOW_TRANSFORMED_NAMES_OPTION, NULL, 0,
    N_("show file or archive names after transformation"),
    GRID_INFORMATIVE },
-  {"show-stored-names", 0, 0, OPTION_ALIAS, NULL, GRID_INFORMATIVE },
+  {"show-stored-names", 0, NULL, OPTION_ALIAS, NULL, GRID_INFORMATIVE },
   {"quoting-style", QUOTING_STYLE_OPTION, N_("STYLE"), 0,
    N_("set name quoting style; see below for valid STYLE values"), GRID_INFORMATIVE },
   {"quote-chars", QUOTE_CHARS_OPTION, N_("STRING"), 0,
    N_("additionally quote characters from STRING"), GRID_INFORMATIVE },
   {"no-quote-chars", NO_QUOTE_CHARS_OPTION, N_("STRING"), 0,
    N_("disable quoting for characters from STRING"), GRID_INFORMATIVE },
-  {"interactive", 'w', 0, 0,
+  {"interactive", 'w', NULL, 0,
    N_("ask for confirmation for every action"), GRID_INFORMATIVE },
-  {"confirmation", 0, 0, OPTION_ALIAS, NULL, GRID_INFORMATIVE },
-  {"verbose", 'v', 0, 0,
+  {"confirmation", 0, NULL, OPTION_ALIAS, NULL, GRID_INFORMATIVE },
+  {"verbose", 'v', NULL, 0,
    N_("verbosely list files processed"), GRID_INFORMATIVE },
   {"warning", WARNING_OPTION, N_("KEYWORD"), 0,
    N_("warning control"), GRID_INFORMATIVE },
@@ -910,16 +910,16 @@ static struct argp_option options[] = {
   {NULL, 0, NULL, 0,
    N_("Compatibility options:"), GRH_COMPAT },
 
-  {NULL, 'o', 0, 0,
+  {NULL, 'o', NULL, 0,
    N_("when creating, same as --old-archive; when extracting, same as --no-same-owner"), GRID_COMPAT },
 
   {NULL, 0, NULL, 0,
    N_("Other options:"), GRH_OTHER },
 
-  {"restrict", RESTRICT_OPTION, 0, 0,
+  {"restrict", RESTRICT_OPTION, NULL, 0,
    N_("disable use of some potentially harmful options"), -1 },
 
-  {0, 0, 0, 0, 0, 0}
+  {NULL, 0, NULL, 0, NULL, 0}
 };
 
 static char const *const atime_preserve_args[] =
@@ -2242,7 +2242,7 @@ find_argp_option_key (struct argp_option const *o, char key)
   for (;
        !(o->name == NULL
         && o->key == 0
-        && o->arg == 0
+        && o->arg == NULL
         && o->flags == 0
         && o->doc == NULL); o++)
     if (o->key == key)
@@ -2325,7 +2325,7 @@ parse_default_options (struct tar_args *args)
 {
   char *opts = getenv ("TAR_OPTIONS");
   struct wordsplit ws;
-  struct option_locus loc = { OPTS_ENVIRON, "TAR_OPTIONS", 0, 0 };
+  struct option_locus loc = { OPTS_ENVIRON, "TAR_OPTIONS", 0, NULL };
   struct option_locus *save_loc_ptr;
 
   if (!opts)
@@ -2445,7 +2445,7 @@ decode_options (int argc, char **argv)
 
       while (in < argv + argc)
        *out++ = *in++;
-      *out = 0;
+      *out = NULL;
 
       /* Replace the old option list by the new one.  */
 
@@ -2857,7 +2857,7 @@ main (int argc, char **argv)
   exit_status = TAREXIT_SUCCESS;
   error_hook = checkpoint_flush_actions;
 
-  set_quoting_style (0, DEFAULT_QUOTING_STYLE);
+  set_quoting_style (NULL, DEFAULT_QUOTING_STYLE);
 
   close_stdout_set_file_name (_("stdout"));
 
@@ -2963,7 +2963,7 @@ tar_stat_close (struct tar_stat_info *st)
   int status = (st->dirstream ? closedir (st->dirstream)
                : 0 < st->fd ? close (st->fd)
                : 0);
-  st->dirstream = 0;
+  st->dirstream = NULL;
   st->fd = 0;
 
   if (status == 0)

diff --git a/src/update.c b/src/update.c
index 15b8575d4216f7d4172f98967361d7578c7aabfa..872e701fc39782ae53e91c34ace0fe5f0615876b 100644 (file)
--- a/src/update.c
+++ b/src/update.c
@@ -221,7 +221,7 @@ update_archive (void)
        if (subcommand_option == CAT_SUBCOMMAND)
          append_file (file_name);
        else
-         dump_file (0, file_name, file_name);
+         dump_file (NULL, file_name, file_name);
       }
   }
 

diff --git a/src/utf8.c b/src/utf8.c
index 3c4d3b792e42ff3f93449212a9a619cc741ab6bd..2d4a6ec7dc567b8394cbf19c90964360d09403b7 100644 (file)
--- a/src/utf8.c
+++ b/src/utf8.c
@@ -73,7 +73,7 @@ utf8_convert (bool to_utf, char const *input, char **output)
   size_t outlen;
   iconv_t cd = utf8_init (to_utf);
 
-  if (cd == 0)
+  if (!cd)
     {
       *output = xstrdup (input);
       return true;

diff --git a/src/xheader.c b/src/xheader.c
index 2f228259308151367983c5ccdb035ecb16099fe9..4dddc536223a2e152486296c660d62d0e1d4574a 100644 (file)
--- a/src/xheader.c
+++ b/src/xheader.c
@@ -904,7 +904,7 @@ xheader_destroy (struct xheader *xhdr)
     }
   else
     free (xhdr->buffer);
-  xhdr->buffer = 0;
+  xhdr->buffer = NULL;
   xhdr->size = 0;
 }