Actually report errors. Don't leave empty files.

maint/doctest

@@ -1,9 +1,28 @@
 #!/bin/sh
 
+set -e
+
+function one_test () {
+	"$@" >/dev/null 2>doctest.err
+	if test -s doctest.err; then
+		echo "ERROR messages follow:" 2>&1
+		cat doctest.err 2>&1
+		echo "ERROR while running following command:" 2>&1
+		echo "$@" 2>&1
+		echo "ERROR messages are preserved in doctest.err"
+		exit 1
+	fi
+}
+
+test -r doc/mc.1.in || { echo "ERROR: cannot read doc/mc.1.in" 2>&1; exit 1; }
+
 # Test the documentation for possible errors.
-find doc -name '*.[1-9].in' -exec groff -wall -mandoc -Tps {} \; >/dev/null 2>doctest-ps.out
-find doc -name '*.[1-9].in' -exec groff -wall -mandoc -Tdvi {} \; >/dev/null 2>doctest-dvi.out
-find doc -name '*.[1-9].in' -exec nroff -mandoc -Tlatin1 {} \; >/dev/null 2>doctest-nroff.out
+one_test find doc -name '*.[1-9].in' -exec groff -wall -mandoc -Tps {} \;
+one_test find doc -name '*.[1-9].in' -exec groff -wall -mandoc -Tdvi {} \;
+one_test find doc -name '*.[1-9].in' -exec nroff -mandoc -Tlatin1 {} \;
 
 # Check English manuals to be in ASCII.
-find doc -maxdepth 1 -name '*.[1-9].in' -exec groff -wall -Tascii {} \; >/dev/null 2>doctest-ascii.out
+one_test find doc -maxdepth 1 -name '*.[1-9].in' -exec groff -wall -Tascii {} \;
+
+rm -rf doctest.err
+exit 0