build: remove --without-fts configure option

Trying to use this option lead to this error since v4.5.17-6-gfc260795:
  configure: error: Using --without-fts is not longer supported

* configure.ac (FIND_WITH_FTS): Remove.
* m4/withfts.m4: Remove file.
* NEWS: Document this build-related change.

3 files changed, 6 insertions, 14 deletions

diff --git a/NEWS b/NEWS
index fb58ac1b..d103c23c 100644
--- a/NEWS
+++ b/NEWS
@@ -15,6 +15,12 @@ of each constructed command line to be executed.  [#57291]
 
 #35253: Clarify descriptions of -printf %f, %h.
 
+** Changes to the build process
+
+The configure option --without-fts has been removed.  The attempt to use
+it stopped configure with an error message since 4.5.18 (2015) anyway.
+
+
 * Major changes in release 4.7.0, 2019-08-29
 
 ** Changes to locate / updatedb
diff --git a/configure.ac b/configure.ac
index 05fdf785..58838422 100644
--- a/configure.ac
+++ b/configure.ac
@@ -52,8 +52,6 @@ AC_CANONICAL_HOST
 AC_CONFIG_MACRO_DIR(gl/m4)
 
 AC_SUBST(AUXDIR,$ac_aux_dir)
-dnl check for --with-fts
-FIND_WITH_FTS
 
 AC_ARG_ENABLE(leaf-optimisation,
 	AS_HELP_STRING(--enable-leaf-optimisation,Enable an optimisation which saves lstat calls to identify subdirectories on filesystems having traditional Unix semantics),
diff --git a/m4/withfts.m4 b/m4/withfts.m4
deleted file mode 100644
index 71a93af8..00000000
--- a/m4/withfts.m4
+++ /dev/null
@@ -1,12 +0,0 @@
-dnl This macro is being phased out; --with-fts is now mandatory.  The
-dnl oldfind binary is no longer installed.
-AC_DEFUN([FIND_WITH_FTS],
-[AC_ARG_WITH([fts],
-[  --without-fts           Use an older mechanism for searching the filesystem, instead of using fts()],[with_fts=$withval],[])
-  case $with_fts in
-        yes) ;;
-        '')     with_fts=yes ;;
-	no)	AC_MSG_ERROR([Using --without-fts is not longer supported]) ;;
-        *) AC_MSG_ERROR([Invalid value for --with-fts: $with_fts])
-  esac
-])