# the reason for skip/failure to console, rather than to the .log files.
: ${stderr_fileno_=2}
-warn_ () { echo "$@" 1>&$stderr_fileno_; }
+# Note that correct expansion of "$*" depends on IFS starting with ' '.
+# Always write the full diagnostic to stderr.
+# When stderr_fileno_ is not 2, also emit the first line of the
+# diagnostic to that file descriptor.
+warn_ ()
+{
+ # If IFS does not start with ' ', set it and emit the warning in a subshell.
+ case $IFS in
+ ' '*) printf '%s\n' "$*" >&2
+ test $stderr_fileno_ = 2 \
+ || { printf '%s\n' "$*" | sed 1q >&$stderr_fileno_ ; } ;;
+ *) (IFS=' '; warn_ "$@");;
+ esac
+}
fail_ () { warn_ "$ME_: failed test: $@"; Exit 1; }
skip_ () { warn_ "$ME_: skipped test: $@"; Exit 77; }
fatal_ () { warn_ "$ME_: hard error: $@"; Exit 99; }
# a partition, or to undo any other global state changes.
cleanup_ () { :; }
-if ( diff --version < /dev/null 2>&1 | grep GNU ) > /dev/null 2>&1; then
+if ( diff -u "$0" "$0" < /dev/null ) > /dev/null 2>&1; then
compare () { diff -u "$@"; }
+elif ( diff -c "$0" "$0" < /dev/null ) > /dev/null 2>&1; then
+ compare () { diff -c "$@"; }
elif ( cmp --version < /dev/null 2>&1 | grep GNU ) > /dev/null 2>&1; then
compare () { cmp -s "$@"; }
else