diff --git a/coreutils/df.c b/coreutils/df.c
index d95aff39d..4bbfe943b 100644
--- a/coreutils/df.c
+++ b/coreutils/df.c
@@ -119,7 +119,7 @@ int df_main(int argc, char **argv)
 			mount_point = *argv++;
 			if (!mount_point)
 				break;
-			mount_entry = find_mount_point(mount_point);
+			mount_entry = find_mount_point(mount_point, 1);
 			if (!mount_entry) {
 				bb_error_msg("%s: can't find mount point", mount_point);
  set_error:
diff --git a/include/libbb.h b/include/libbb.h
index 936d98a23..c7b4de13c 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -995,7 +995,7 @@ extern void run_applet_no_and_exit(int a, char **argv) NORETURN FAST_FUNC;
 
 #ifdef HAVE_MNTENT_H
 extern int match_fstype(const struct mntent *mt, const char *fstypes) FAST_FUNC;
-extern struct mntent *find_mount_point(const char *name) FAST_FUNC;
+extern struct mntent *find_mount_point(const char *name, int subdir_too) FAST_FUNC;
 #endif
 extern void erase_mtab(const char * name) FAST_FUNC;
 extern unsigned int tty_baud_to_value(speed_t speed) FAST_FUNC;
diff --git a/libbb/find_mount_point.c b/libbb/find_mount_point.c
index 12b2cfce4..bcb18effe 100644
--- a/libbb/find_mount_point.c
+++ b/libbb/find_mount_point.c
@@ -17,27 +17,29 @@
  * Given any other file (or directory), find the mount table entry for its
  * filesystem.
  */
-struct mntent* FAST_FUNC find_mount_point(const char *name)
+struct mntent* FAST_FUNC find_mount_point(const char *name, int subdir_too)
 {
 	struct stat s;
-	dev_t mountDevice;
-	FILE *mountTable;
+	FILE *mtab_fp;
 	struct mntent *mountEntry;
+	dev_t devno_of_name;
+	bool block_dev;
 
 	if (stat(name, &s) != 0)
 		return NULL;
 
-	if (S_ISBLK(s.st_mode))
-		mountDevice = s.st_rdev;
-	else
-		mountDevice = s.st_dev;
+	devno_of_name = s.st_dev;
+	block_dev = 0;
+	if (S_ISBLK(s.st_mode)) {
+		devno_of_name = s.st_rdev;
+		block_dev = 1;
+	}
 
+	mtab_fp = setmntent(bb_path_mtab_file, "r");
+	if (!mtab_fp)
+		return NULL;
 
-	mountTable = setmntent(bb_path_mtab_file, "r");
-	if (!mountTable)
-		return 0;
-
-	while ((mountEntry = getmntent(mountTable)) != NULL) {
+	while ((mountEntry = getmntent(mtab_fp)) != NULL) {
 		/* rootfs mount in Linux 2.6 exists always,
 		 * and it makes sense to always ignore it.
 		 * Otherwise people can't reference their "real" root! */
@@ -49,13 +51,18 @@ struct mntent* FAST_FUNC find_mount_point(const char *name)
 		) { /* String match. */
 			break;
 		}
-		/* Match the device. */
-		if (stat(mountEntry->mnt_fsname, &s) == 0 && s.st_rdev == mountDevice)
+
+		if (!(subdir_too || block_dev))
+			continue;
+
+		/* Is device's dev_t == name's dev_t? */
+		if (stat(mountEntry->mnt_fsname, &s) == 0 && s.st_rdev == devno_of_name)
 			break;
 		/* Match the directory's mount point. */
-		if (stat(mountEntry->mnt_dir, &s) == 0 && s.st_dev == mountDevice)
+		if (stat(mountEntry->mnt_dir, &s) == 0 && s.st_dev == devno_of_name)
 			break;
 	}
-	endmntent(mountTable);
+	endmntent(mtab_fp);
+
 	return mountEntry;
 }
diff --git a/testsuite/README b/testsuite/README
index 3c52254dd..03ac377ba 100644
--- a/testsuite/README
+++ b/testsuite/README
@@ -27,6 +27,8 @@ For busybox built against uclibc, /etc/TZ does not exist or does not match
 host system timezone setting. For glibc based host systems, timezona settings
 are in /etc/localtime.
 
+LANG and LC_xxx environment variables set to non-C locale.
+
 
 For the entire testsuite, the copyright is as follows:
 
diff --git a/testsuite/cpio.tests b/testsuite/cpio.tests
index 576180ff1..fa0b65a08 100755
--- a/testsuite/cpio.tests
+++ b/testsuite/cpio.tests
@@ -41,6 +41,7 @@ ls -ln cpio.testdir | $FILTER_LS" \
 " \
 	"" ""
 
+test x"$SKIP_KNOWN_BUGS" = x"" && {
 # Currently fails. Numerous buglets: "1 blocks" versus "1 block",
 # "1 block" must go to stderr, does not list cpio.testdir/x and cpio.testdir/y
 testing "cpio lists hardlinks" \
@@ -53,6 +54,7 @@ cpio.testdir/y
 0
 " \
 	"" ""
+}
 
 # More complex case
 rm -rf cpio.testdir cpio.testdir2 2>/dev/null
diff --git a/testsuite/mount.tests b/testsuite/mount.tests
index 5374ecbd6..c8381a0de 100755
--- a/testsuite/mount.tests
+++ b/testsuite/mount.tests
@@ -1,5 +1,4 @@
 #!/bin/sh
-
 # Copyright 2007 by Denys Vlasenko <vda.linux@googlemail.com>
 # Licensed under GPL v2, see file LICENSE for details.
 
@@ -10,8 +9,8 @@ test "`id -u`" = 0 || {
 	exit 0
 }
 
-dd if=/dev/zero of=mount.image1m count=1 bs=1M 2>/dev/null || exit 1
-mkfs.minix -v mount.image1m >/dev/null 2>&1 || exit 1
+dd if=/dev/zero of=mount.image1m count=1 bs=1M 2>/dev/null || { echo "dd error"; exit 1; }
+mkfs.minix -v mount.image1m >/dev/null 2>&1 || { echo "mkfs.minix error"; exit 1; }
 testdir=$PWD/testdir
 mkdir $testdir 2>/dev/null
 umount -d $testdir 2>/dev/null
diff --git a/testsuite/od.tests b/testsuite/od.tests
index 69c29952a..f136bb5fa 100755
--- a/testsuite/od.tests
+++ b/testsuite/od.tests
@@ -10,7 +10,7 @@ testing "od -b" \
 	"od -b" \
 "\
 0000000 110 105 114 114 117
-0000006
+0000005
 " \
 	"" "HELLO"
 
diff --git a/testsuite/runtest b/testsuite/runtest
index 5560f7bc2..2428f6c36 100755
--- a/testsuite/runtest
+++ b/testsuite/runtest
@@ -1,20 +1,8 @@
 #!/bin/sh
-
 # Usage:
 # runtest [applet1] [applet2...]
 
-# Helper for helpers. Oh my...
-test x"$ECHO" != x"" || {
-	ECHO="echo"
-	test x"`echo -ne`" = x"" || {
-		# Compile and use a replacement 'echo' which understands -e -n
-		ECHO="$PWD/echo-ne"
-		test -x "$ECHO" || {
-			gcc -Os -o "$ECHO" ../scripts/echo.c || exit 1
-		}
-	}
-	export ECHO
-}
+. testing.sh
 
 # Run one old-style test.
 # Tests are stored in applet/testcase shell scripts.
diff --git a/testsuite/sed.tests b/testsuite/sed.tests
index 677303be1..a9d9ada31 100755
--- a/testsuite/sed.tests
+++ b/testsuite/sed.tests
@@ -51,8 +51,10 @@ testing "sed -n" "sed -n -e s/foo/bar/ -e s/bar/baz/" "" "" "foo\n"
 testing "sed s//p" "sed -e s/foo/bar/p -e s/bar/baz/p" "bar\nbaz\nbaz\n" \
 	"" "foo\n"
 testing "sed -n s//p" "sed -ne s/abc/def/p" "def\n" "" "abc\n"
+test x"$SKIP_KNOWN_BUGS" = x"" && {
 testing "sed s//g (exhaustive)" "sed -e 's/[[:space:]]*/,/g'" ",1,2,3,4,5,\n" \
 	"" "12345\n"
+}
 testing "sed s arbitrary delimiter" "sed -e 's woo boing '" "boing\n" "" "woo\n"
 testing "sed s chains" "sed -e s/foo/bar/ -e s/bar/baz/" "baz\n" "" "foo\n"
 testing "sed s chains2" "sed -e s/foo/bar/ -e s/baz/nee/" "bar\n" "" "foo\n"
@@ -72,6 +74,7 @@ testing "sed t (test/branch clears test bit)" "sed -e 's/a/b/;:loop;t loop'" \
 testing "sed T (!test/branch)" "sed -e 's/a/1/;T notone;p;: notone;p'" \
 	"1\n1\n1\nb\nb\nc\nc\n" "" "a\nb\nc\n"
 
+test x"$SKIP_KNOWN_BUGS" = x"" && {
 # Normal sed end-of-script doesn't print "c" because n flushed the pattern
 # space.  If n hits EOF, pattern space is empty when script ends.
 # Query: how does this interact with no newline at EOF?
@@ -80,6 +83,7 @@ testing "sed n (flushes pattern space, terminates early)" "sed -e 'n;p'" \
 # N does _not_ flush pattern space, therefore c is still in there @ script end.
 testing "sed N (doesn't flush pattern space when terminating)" "sed -e 'N;p'" \
 	"a\nb\na\nb\nc\n" "" "a\nb\nc\n"
+}
 testing "sed address match newline" 'sed "/b/N;/b\\nc/i woo"' \
 	"a\nwoo\nb\nc\nd\n" "" "a\nb\nc\nd\n"
 
@@ -99,13 +103,17 @@ testing "sed d ends script iteration (2)" \
 	"sed -e '/ook/d;a\' -e 'bang'" "woot\nbang\n" "" "ook\nwoot\n"
 
 # Multiple files, with varying newlines and NUL bytes
+test x"$SKIP_KNOWN_BUGS" = x"" && {
 testing "sed embedded NUL" "sed -e 's/woo/bang/'" "\0bang\0woo\0" "" \
 	"\0woo\0woo\0"
+}
 testing "sed embedded NUL g" "sed -e 's/woo/bang/g'" "bang\0bang\0" "" \
 	"woo\0woo\0"
+test x"$SKIP_KNOWN_BUGS" = x"" && {
 echo -e "/woo/a he\0llo" > sed.commands
 testing "sed NUL in command" "sed -f sed.commands" "woo\nhe\0llo\n" "" "woo"
 rm sed.commands
+}
 
 # sed has funky behavior with newlines at the end of file.  Test lots of
 # corner cases with the optional newline appending behavior.
@@ -120,8 +128,10 @@ testing "sed empty file plus cat" "sed -e 's/nohit//' input -" "one\ntwo" \
 	"" "one\ntwo"
 testing "sed cat plus empty file" "sed -e 's/nohit//' input -" "one\ntwo" \
 	"one\ntwo" ""
+test x"$SKIP_KNOWN_BUGS" = x"" && {
 testing "sed append autoinserts newline" "sed -e '/woot/a woo' -" \
 	"woot\nwoo\n" "" "woot"
+}
 testing "sed insert doesn't autoinsert newline" "sed -e '/woot/i woo' -" \
 	"woo\nwoot" "" "woot"
 testing "sed print autoinsert newlines" "sed -e 'p' -" "one\none" "" "one"
@@ -137,9 +147,11 @@ testing "sed selective matches insert newline" \
 testing "sed selective matches noinsert newline" \
 	"sed -ne 's/woo/bang/p' input -" "a bang\nb bang" "a woo\nb woo" \
 	"c no\nd no"
+test x"$SKIP_KNOWN_BUGS" = x"" && {
 testing "sed clusternewline" \
 	"sed -e '/one/a 111' -e '/two/i 222' -e p input -" \
 	"one\none\n111\n222\ntwo\ntwo" "one" "two"
+}
 testing "sed subst+write" \
 	"sed -e 's/i/z/' -e 'woutputw' input -; echo -n X; cat outputw" \
 	"thzngy\nagaznXthzngy\nagazn" "thingy" "again"
@@ -175,8 +187,12 @@ testing "sed lie-to-autoconf" "sed --version | grep -o 'GNU sed version '" \
 	"GNU sed version \n" "" ""
 
 # Jump to nonexistent label
-testing "sed nonexistent label" "sed -e 'b walrus' 2> /dev/null || echo yes" \
+test x"$SKIP_KNOWN_BUGS" = x"" && {
+# Incompatibility: illegal jump is not detected if input is ""
+# (that is, no lines at all). GNU sed 4.1.5 complains even in this case
+testing "sed nonexistent label" "sed -e 'b walrus' 2>/dev/null || echo yes" \
 	"yes\n" "" ""
+}
 
 testing "sed backref from empty s uses range regex" \
 	"sed -e '/woot/s//eep \0 eep/'" "eep woot eep" "" "woot"
diff --git a/testsuite/sort.tests b/testsuite/sort.tests
index f700dc0c1..627ca51f8 100755
--- a/testsuite/sort.tests
+++ b/testsuite/sort.tests
@@ -45,8 +45,8 @@ egg	1	2	papyrus
 999	3	0	algebra
 " "$data" ""
 
-# Busybox is definitely doing this one wrong just now.  FIXME
-
+test x"$SKIP_KNOWN_BUGS" = x"" && {
+# Busybox is definitely doing these wrong.  FIXME
 testing "sort key range with numeric option and global reverse" \
 "sort -k2,3n -r input" \
 "egg	1	2	papyrus
@@ -56,8 +56,6 @@ testing "sort key range with numeric option and global reverse" \
 7	3	42	soup
 " "$data" ""
 
-#
-
 testing "sort key range with multiple options" "sort -k2,3rn input" \
 "7	3	42	soup
 999	3	0	algebra
@@ -65,6 +63,7 @@ testing "sort key range with multiple options" "sort -k2,3rn input" \
 42	1	3	woot
 egg	1	2	papyrus
 " "$data" ""
+}
 
 testing "sort key range with two -k options" "sort -k 2,2n -k 1,1r input" "\
 d 2
diff --git a/testsuite/testing.sh b/testsuite/testing.sh
index a57c4d68d..22c640faf 100755
--- a/testsuite/testing.sh
+++ b/testsuite/testing.sh
@@ -36,6 +36,20 @@
 export FAILCOUNT=0
 export SKIP=
 
+# Helper for helpers. Oh my...
+
+test x"$ECHO" != x"" || {
+	ECHO="echo"
+	test x"`echo -ne`" = x"" || {
+		# Compile and use a replacement 'echo' which understands -e -n
+		ECHO="$PWD/echo-ne"
+		test -x "$ECHO" || {
+			gcc -Os -o "$ECHO" ../scripts/echo.c || exit 1
+		}
+	}
+	export ECHO
+}
+
 # Helper functions
 
 optional()
@@ -73,7 +87,7 @@ testing()
 
   $ECHO -ne "$3" > expected
   $ECHO -ne "$4" > input
-  [ -z "$VERBOSE" ] || echo "echo '$5' | $2"
+  [ -z "$VERBOSE" ] || echo "echo -ne '$5' | $2"
   $ECHO -ne "$5" | eval "$2" > actual
   RETVAL=$?
 
diff --git a/util-linux/fsck_minix.c b/util-linux/fsck_minix.c
index ca0b17efe..5d1d2af31 100644
--- a/util-linux/fsck_minix.c
+++ b/util-linux/fsck_minix.c
@@ -374,7 +374,7 @@ static int ask(const char *string, int def)
  */
 static void check_mount(void)
 {
-	if (find_mount_point(device_name)) {
+	if (find_mount_point(device_name, 0)) {
 		int cont;
 #if ENABLE_FEATURE_MTAB_SUPPORT
 		/*
diff --git a/util-linux/mkfs_minix.c b/util-linux/mkfs_minix.c
index 18512a395..cf757610b 100644
--- a/util-linux/mkfs_minix.c
+++ b/util-linux/mkfs_minix.c
@@ -682,7 +682,7 @@ int mkfs_minix_main(int argc UNUSED_PARAM, char **argv)
 		G.total_blocks = 65535;
 
 	/* Check if it is mounted */
-	if (find_mount_point(G.device_name))
+	if (find_mount_point(G.device_name, 0))
 		bb_error_msg_and_die("can't format mounted filesystem");
 
 	xmove_fd(xopen(G.device_name, O_RDWR), dev_fd);
diff --git a/util-linux/mkfs_vfat.c b/util-linux/mkfs_vfat.c
index dff10f9e1..bdd4dd803 100644
--- a/util-linux/mkfs_vfat.c
+++ b/util-linux/mkfs_vfat.c
@@ -279,7 +279,7 @@ int mkfs_vfat_main(int argc UNUSED_PARAM, char **argv)
 		)
 			bb_error_msg_and_die("will not try to make filesystem on full-disk device (use -I if wanted)");
 		// can't work on mounted filesystems
-		if (find_mount_point(device_name))
+		if (find_mount_point(device_name, 0))
 			bb_error_msg_and_die("can't format mounted filesystem");
 #endif
 		// get true sector size