D7: editor multi-cursor support

Add secondary_cursors field to Editor with insert_char_multi,
delete_back_multi, delete_forward_multi methods. Right-to-left
processing ensures position shifts don't corrupt earlier insertions.

7 new tests: add/clear, all_positions, insert, delete_back,
delete_forward, unicode, duplicate-add.

local/recipes/tools/diffutils/source/gnulib-tests/test-init.sh

@@ -0,0 +1,74 @@
+#!/bin/sh
+# Unit tests for init.sh
+# Copyright (C) 2011-2017 Free Software Foundation, Inc.
+# This file is part of the GNUlib Library.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+: ${srcdir=.}
+. "$srcdir/init.sh"; path_prepend_ .
+
+fail=0
+
+test_compare()
+{
+  touch empty || fail=1
+  echo xyz > in || fail=1
+
+  compare /dev/null /dev/null >out 2>err || fail=1
+  test -s out && fail_ "out not empty: $(cat out)"
+  # "err" should be empty, too, but has "set -x" output when VERBOSE=yes
+  case $- in *x*) ;; *) test -s err && fail_ "err not empty: $(cat err)";; esac
+
+  compare /dev/null empty >out 2>err || fail=1
+  test -s out && fail_ "out not empty: $(cat out)"
+  case $- in *x*) ;; *) test -s err && fail_ "err not empty: $(cat err)";; esac
+
+  compare in in >out 2>err || fail=1
+  test -s out && fail_ "out not empty: $(cat out)"
+  case $- in *x*) ;; *) test -s err && fail_ "err not empty: $(cat err)";; esac
+
+  compare /dev/null in >out 2>err && fail=1
+  cat <<\EOF > exp
+diff -u /dev/null in
+--- /dev/null	1970-01-01
++++ in	1970-01-01
++xyz
+EOF
+  compare exp out || fail=1
+  case $- in *x*) ;; *) test -s err && fail_ "err not empty: $(cat err)";; esac
+
+  compare empty in >out 2>err && fail=1
+  # Compare against expected output only if compare is using diff -u.
+  if grep @ out >/dev/null; then
+    # Remove the TAB-date suffix on each --- and +++ line,
+    # for both the expected and the actual output files.
+    # Also remove the @@ line, since Solaris 5.10 and GNU diff formats differ:
+    # -@@ -0,0 +1 @@
+    # +@@ -1,0 +1,1 @@
+    # Also, remove space after leading '+', since AIX 7.1 diff outputs a space.
+    sed 's/	.*//;/^@@/d;s/^+ /+/' out > k && mv k out
+    cat <<\EOF > exp
+--- empty
++++ in
++xyz
+EOF
+    compare exp out || fail=1
+  fi
+  case $- in *x*) ;; *) test -s err && fail_ "err not empty: $(cat err)";; esac
+}
+
+test_compare
+
+Exit $fail