grep: Fix various bugs in recursive tree handling

The -OpS options were effectively ignored due to a collection of
bugs in the use of fts(3):

- fts_open(3) requires one of FTS_PHYSICAL or FTS_LOGICAL to be
  specified, but in the -O case, only FTS_COMFOLLOW was given.  Fix
  this to use FTS_COMFOLLOW | FTS_PHYSICAL.

- The switch on the entry type returned by fts_read() did not check
  for symbolic links, so symbolic links fell into the default case and
  were always passed to procfile() even when -p was given.  Fix this
  by adding cases in the switch statement to explicitly ignore FTS_SL.

- FTS_NOSTAT was passed to fts_open(), so fts_open() couldn't detect
  symbolic links when FTS_PHYSICAL was passed, instead both regular
  files and symbolic links were returned as FTS_NSOK entries.  Fix
  by only using FTS_NOSTAT with FTS_LOGICAL.

While here, fix a few other nits:

- Treat FTS_NS as an error like FTS_DNR and FTS_ERR.

- Just ignore FTS_DP.  The logic to skip descending into skipped
  directories is only relevant when a directory is first visited, not
  after the directory has been visited.

- Use warnc instead of warnx + strerror.

PR:		280676
Reviewed by:	kevans
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D46255

0 files changed, 0 insertions, 0 deletions