seq: fix to always honor the step value

* src/seq.c (main): With 3 positive integer args we were
checking the end value was == "1", rather than the step value.
* tests/misc/seq.pl: Add tests for this case.
Reported by Marcel Böhme in http://bugs.gnu.org/13525

diff --git a/NEWS b/NEWS
index 26939c1..22d90d5 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -57,7 +57,8 @@ GNU coreutils NEWS                                    -*- outline -*-
 
   seq -s no longer prints an erroneous newline after the first number, and
   outputs a newline after the last number rather than a trailing separator.
-  [bug introduced in coreutils-8.20]
+  Also seq no longer ignores a specified step value when the end value is 1.
+  [bugs introduced in coreutils-8.20]
 
 ** Changes in behavior
 

diff --git a/src/seq.c b/src/seq.c
index 5ad5fad..acbe235 100644 (file)
--- a/src/seq.c
+++ b/src/seq.c
@@ -565,11 +565,12 @@ main (int argc, char **argv)
      then use the much more efficient integer-only code.  */
   if (all_digits_p (argv[optind])
       && (n_args == 1 || all_digits_p (argv[optind + 1]))
-      && (n_args < 3 || STREQ ("1", argv[optind + 2]))
+      && (n_args < 3 || (STREQ ("1", argv[optind + 1])
+                         && all_digits_p (argv[optind + 2])))
       && !equal_width && !format_str && strlen (separator) == 1)
     {
       char const *s1 = n_args == 1 ? "1" : argv[optind];
-      char const *s2 = n_args == 1 ? argv[optind] : argv[optind + 1];
+      char const *s2 = argv[optind + (n_args - 1)];
       if (seq_fast (s1, s2))
         exit (EXIT_SUCCESS);
 

diff --git a/tests/misc/seq.pl b/tests/misc/seq.pl
index 64c62b2..b3496d6 100755 (executable)
--- a/tests/misc/seq.pl
+++ b/tests/misc/seq.pl
@@ -137,6 +137,17 @@ my @Tests =
    ['sep-1', qw(-s, 1 3), {OUT => [qw(1,2,3)]}],
    ['sep-2', qw(-s, 1 1), {OUT => [qw(1)]}],
    ['sep-3', qw(-s,, 1 3), {OUT => [qw(1,,2,,3)]}],
+
+   # Exercise fast path avoidance logic.
+   # In 8.20 a step value != 1, with positive integer start and end was broken
+   ['not-fast-1', qw(1 3 1), {OUT => [qw(1)]}],
+   ['not-fast-2', qw(1 1 4.2), {OUT => [qw(1 2 3 4)]}],
+   ['not-fast-3', qw(1 1 0)],
+
+   # Ensure the correct parameters are passed to the fast path
+   ['fast-1', qw(4), {OUT => [qw(1 2 3 4)]}],
+   ['fast-2', qw(1 4), {OUT => [qw(1 2 3 4)]}],
+   ['fast-3', qw(1 1 4), {OUT => [qw(1 2 3 4)]}],
   );
 
 # Append a newline to each entry in the OUT array.