udevadm-verify: add support for directory arguments

When an argument specified to udevadm verify is a directory,
verify all *.rules files in that directory.

Suggested-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>

test/units/testsuite-17.11.sh

@@ -31,6 +31,12 @@ cat >"${workdir}/default_output_1_fail" <<EOF
   Success: 0
   Fail:    1
 EOF
+cat >"${workdir}/output_0_files" <<EOF
+
+0 udev rules files have been checked.
+  Success: 0
+  Fail:    0
+EOF
 
 test_number=0
 rules=
@@ -52,8 +58,10 @@ next_test_number() {
 
 assert_0() {
     udevadm verify "$@" >"${out}"
-    if [ -f "${rules}" ]; then
-       diff -u "${workdir}/default_output_1_success" "${out}"
+    if [ -f "${exo}" ]; then
+        diff -u "${exo}" "${out}"
+    elif [ -f "${rules}" ]; then
+        diff -u "${workdir}/default_output_1_success" "${out}"
     fi
 
     next_test_number
@@ -97,28 +105,40 @@ assert_1 -N now
 assert_1 --resolve-names
 # --resolve-names= takes "early" or "never"
 assert_1 --resolve-names=now
-# Failed to parse rules file .: Is a directory
-cp "${workdir}/default_output_1_fail" "${exo}"
-assert_1 .
 # Failed to parse rules file ./nosuchfile: No such file or directory
 assert_1 ./nosuchfile
-# Failed to parse rules file .: Is a directory
+# Failed to parse rules file ./nosuchfile: No such file or directory
 cat >"${exo}" <<EOF
 
 3 udev rules files have been checked.
   Success: 2
   Fail:    1
 EOF
-assert_1 /dev/null . /dev/null
+assert_1 /dev/null ./nosuchfile /dev/null
 
 rules_dir='etc/udev/rules.d'
 mkdir -p "${rules_dir}"
 # No rules files found in $PWD
 assert_1 --root="${workdir}"
 
+# Directory without rules.
+cp "${workdir}/output_0_files" "${exo}"
+assert_0 "${rules_dir}"
+
+# Directory with a loop.
+ln -s . "${rules_dir}/loop.rules"
+cp "${workdir}/default_output_1_fail" "${exo}"
+assert_1 "${rules_dir}"
+rm "${rules_dir}/loop.rules"
+
+# Empty rules.
 touch "${rules_dir}/empty.rules"
 assert_0 --root="${workdir}"
 
+# Directory with a single *.rules file.
+cp "${workdir}/default_output_1_success" "${exo}"
+assert_0 "${rules_dir}"
+
 # Combination of --root= and FILEs is not supported.
 assert_1 --root="${workdir}" /dev/null
 # No rules files found in nosuchdir
@@ -396,5 +416,12 @@ assert_1 "${rules}"
 sed "s|sample-[0-9]*.rules|${workdir}/${rules_dir}/&|" sample-*.exp >"${workdir}/${exp}"
 cd -
 assert_1 --root="${workdir}"
+cd -
+
+# udevadm verify path/
+sed "s|sample-[0-9]*.rules|${workdir}/${rules_dir}/&|" sample-*.exp >"${workdir}/${exp}"
+cd -
+assert_1 "${rules_dir}"
+cd -
 
 exit 0