Remove arbitrary restrictions on sizes, fixing a bug reported

by Geoff Whale.

(skip_fields, skip_chars, check_chars): Now size_t, not int.
(size_opt): New function.  Do not arbitrarily reject size zero.
Change the wording of the error message slightly, for convenience.
(find_field): Use size_t, not int, to compute sizes.
(different, main): check_chars==0 is no longer a special case, as
it defaults to SIZE_MAX.
(main): Check for overflow with args like -234234234234234.
Use 'size_opt' to convert optional arguments to sizes.

diff --git a/src/uniq.c b/src/uniq.c
index 42f33a2064f2f92b487e367a263895d49d95b3b6..4f870bf3d99a7f7ce43d8181e5168be4c6481c93 100644 (file)
--- a/src/uniq.c
+++ b/src/uniq.c
@@ -50,13 +50,13 @@
 char *program_name;
 
 /* Number of fields to skip on each line when doing comparisons. */
-static int skip_fields;
+static size_t skip_fields;
 
 /* Number of chars to skip after skipping any fields. */
-static int skip_chars;
+static size_t skip_chars;
 
-/* Number of chars to compare; if 0, compare the whole lines. */
-static int check_chars;
+/* Number of chars to compare. */
+static size_t check_chars;
 
 enum countmode
 {
@@ -161,13 +161,26 @@ Fields are skipped before chars.\n\
   exit (status == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
 }
 
+/* Convert OPT to size_t, reporting an error using MSGID if it does
+   not fit.  */
+
+static size_t
+size_opt (char const *opt, char const *msgid)
+{
+  unsigned long int size;
+  if (xstrtoul (opt, NULL, 10, &size, "") != LONGINT_OK
+      || SIZE_MAX < size)
+    error (EXIT_FAILURE, 0, "%s: %s", opt, _(msgid));
+  return size;
+}
+
 /* Given a linebuffer LINE,
    return a pointer to the beginning of the line's field to be compared. */
 
 static char *
 find_field (const struct linebuffer *line)
 {
-  register int count;
+  register size_t count;
   register char *lp = line->buffer;
   register size_t size = line->length - 1;
   register size_t i = 0;
@@ -196,13 +209,10 @@ different (const char *old, const char *new, size_t oldlen, size_t newlen)
 {
   register int order;
 
-  if (check_chars)
-    {
-      if (oldlen > check_chars)
-       oldlen = check_chars;
-      if (newlen > check_chars)
-       newlen = check_chars;
-    }
+  if (check_chars < oldlen)
+    oldlen = check_chars;
+  if (check_chars < newlen)
+    newlen = check_chars;
 
   /* Use an if-statement here rather than a function variable to
      avoid portability hassles of getting a non-conflicting declaration
@@ -383,7 +393,7 @@ main (int argc, char **argv)
 
   skip_chars = 0;
   skip_fields = 0;
-  check_chars = 0;
+  check_chars = SIZE_MAX;
   mode = output_all;
   countmode = count_none;
   delimit_groups = DM_NONE;
@@ -406,7 +416,13 @@ main (int argc, char **argv)
        case '7':
        case '8':
        case '9':
-         skip_fields = skip_fields * 10 + optc - '0';
+         {
+           size_t s = skip_fields;
+           skip_fields = s * 10 + optc - '0';
+           if (SIZE_MAX / 10 < s || skip_fields < s)
+             error (EXIT_FAILURE, 0, "%s",
+                    _("invalid number of fields to skip"));
+         }
          break;
 
        case 'c':
@@ -428,15 +444,8 @@ main (int argc, char **argv)
          break;
 
        case 'f':               /* Like '-#'. */
-         {
-           long int tmp_long;
-           if (xstrtol (optarg, NULL, 10, &tmp_long, "") != LONGINT_OK
-               || tmp_long <= 0 || tmp_long > INT_MAX)
-             error (EXIT_FAILURE, 0,
-                    _("invalid number of fields to skip: `%s'"),
-                    optarg);
-           skip_fields = (int) tmp_long;
-         }
+         skip_fields = size_opt (optarg,
+                                 N_("invalid number of fields to skip"));
          break;
 
        case 'i':
@@ -444,15 +453,8 @@ main (int argc, char **argv)
          break;
 
        case 's':               /* Like '+#'. */
-         {
-           long int tmp_long;
-           if (xstrtol (optarg, NULL, 10, &tmp_long, "") != LONGINT_OK
-               || tmp_long <= 0 || tmp_long > INT_MAX)
-             error (EXIT_FAILURE, 0,
-                    _("invalid number of bytes to skip: `%s'"),
-                    optarg);
-           skip_chars = (int) tmp_long;
-         }
+         skip_chars = size_opt (optarg,
+                                N_("invalid number of bytes to skip"));
          break;
 
        case 'u':
@@ -460,15 +462,8 @@ main (int argc, char **argv)
          break;
 
        case 'w':
-         {
-           long int tmp_long;
-           if (xstrtol (optarg, NULL, 10, &tmp_long, "") != LONGINT_OK
-               || tmp_long <= 0 || tmp_long > INT_MAX)
-             error (EXIT_FAILURE, 0,
-                    _("invalid number of bytes to compare: `%s'"),
-                    optarg);
-           check_chars = (int) tmp_long;
-         }
+         check_chars = size_opt (optarg,
+                                 N_("invalid number of bytes to compare"));
          break;
 
        case_GETOPT_HELP_CHAR;
@@ -485,16 +480,8 @@ main (int argc, char **argv)
       /* Interpret non-option arguments with leading `+' only
         if we haven't seen `--'.  */
       while (optind < argc && argv[optind][0] == '+')
-       {
-         char *opt_str = argv[optind++];
-         long int tmp_long;
-         if (xstrtol (opt_str, NULL, 10, &tmp_long, "") != LONGINT_OK
-             || tmp_long <= 0 || tmp_long > INT_MAX)
-           error (EXIT_FAILURE, 0,
-                  _("invalid number of bytes to skip: `%s'"),
-                  opt_str);
-         skip_chars = (int) tmp_long;
-       }
+       skip_chars = size_opt (argv[optind++],
+                              N_("invalid number of bytes to skip"));
     }
 
   if (optind < argc)