diff --git a/Config.in b/Config.in
index 4439ce4f9..bb7dd6d5d 100644
--- a/Config.in
+++ b/Config.in
@@ -119,7 +119,7 @@ config LOCALE_SUPPORT
 	  Enable this if your system has locale support and you would like
 	  busybox to support locale settings.
 
-config FEATURE_ASSUME_UNICODE
+config UNICODE_SUPPORT
 	bool "Support Unicode"
 	default n
 	help
@@ -131,10 +131,18 @@ config FEATURE_ASSUME_UNICODE
 	  Probably by the time when busybox will be fully Unicode-clean,
 	  other encodings will be mainly of historic interest.
 
+config UNICODE_USING_LOCALE
+	bool "Use libc routines for Unicode (else uses internal ones)"
+	default n
+	depends on UNICODE_SUPPORT && LOCALE_SUPPORT
+	help
+	  With this option on, Unicode support is implemented using libc
+	  routines. Otherwise, internal implementation is used.
+
 config FEATURE_CHECK_UNICODE_IN_ENV
 	bool "Check $LANG environment variable"
 	default y
-	depends on FEATURE_ASSUME_UNICODE && !LOCALE_SUPPORT
+	depends on UNICODE_SUPPORT && !UNICODE_USING_LOCALE
 	help
 	  With this option on, Unicode support is activated
 	  only if LANG variable has the value of the form "xxxx.utf8"
@@ -143,7 +151,7 @@ config FEATURE_CHECK_UNICODE_IN_ENV
 
 config SUBST_WCHAR
 	int "Character code to substitute unprintable characters with"
-	depends on FEATURE_ASSUME_UNICODE
+	depends on UNICODE_SUPPORT
 	default 63
 	help
 	  Typical values are 63 for '?' (works with any output device),
@@ -152,7 +160,7 @@ config SUBST_WCHAR
 
 config LAST_SUPPORTED_WCHAR
 	int "Range of supported Unicode characters"
-	depends on FEATURE_ASSUME_UNICODE
+	depends on UNICODE_SUPPORT
 	default 767
 	help
 	  Any character with Unicode value bigger than this is assumed
@@ -183,7 +191,7 @@ config LAST_SUPPORTED_WCHAR
 config UNICODE_COMBINING_WCHARS
 	bool "Allow zero-width Unicode characters on output"
 	default n
-	depends on FEATURE_ASSUME_UNICODE
+	depends on UNICODE_SUPPORT
 	help
 	  With this option off, any Unicode char with width of 0
 	  is substituted on output.
@@ -191,7 +199,7 @@ config UNICODE_COMBINING_WCHARS
 config UNICODE_WIDE_WCHARS
 	bool "Allow wide Unicode characters on output"
 	default n
-	depends on FEATURE_ASSUME_UNICODE
+	depends on UNICODE_SUPPORT
 	help
 	  With this option off, any Unicode char with width > 1
 	  is substituted on output.
@@ -199,7 +207,7 @@ config UNICODE_WIDE_WCHARS
 config UNICODE_BIDI_SUPPORT
 	bool "Bidirectional character-aware line input"
 	default n
-	depends on FEATURE_ASSUME_UNICODE && !LOCALE_SUPPORT
+	depends on UNICODE_SUPPORT && !UNICODE_USING_LOCALE
 	help
 	  With this option on, right-to-left Unicode characters
 	  are treated differently on input (e.g. cursor movement).
diff --git a/TODO b/TODO
index 31aae41fd..af4c467c2 100644
--- a/TODO
+++ b/TODO
@@ -324,8 +324,8 @@ This is useful if you build against uclibc with locale support disabled.
 Unicode-dependent applets must call check_unicode_in_env() when they
 begin executing.
 
-Applet code may conditionalize on FEATURE_ASSUME_UNICODE
-in order to use more efficient code if unicode support is not requested.
+Applet code may conditionalize on UNICODE_SUPPORT in order to use
+more efficient code if unicode support is not requested.
 
 Available functions (if you need more, implement them in libbb/unicode.c
 so that they work without LOCALE_SUPPORT too):
diff --git a/TODO_config_nommu b/TODO_config_nommu
index 2c8210cfe..911f02f6b 100644
--- a/TODO_config_nommu
+++ b/TODO_config_nommu
@@ -24,7 +24,7 @@ CONFIG_FEATURE_VERBOSE_USAGE=y
 CONFIG_FEATURE_COMPRESS_USAGE=y
 CONFIG_FEATURE_INSTALLER=y
 # CONFIG_LOCALE_SUPPORT is not set
-# CONFIG_FEATURE_ASSUME_UNICODE is not set
+# CONFIG_UNICODE_SUPPORT is not set
 # CONFIG_FEATURE_CHECK_UNICODE_IN_ENV is not set
 CONFIG_LONG_OPTS=y
 CONFIG_FEATURE_DEVPTS=y
diff --git a/coreutils/cal.c b/coreutils/cal.c
index 79fe074f8..c98229cb0 100644
--- a/coreutils/cal.c
+++ b/coreutils/cal.c
@@ -87,8 +87,8 @@ int cal_main(int argc UNUSED_PARAM, char **argv)
 	/* "Su Mo Tu We Th Fr Sa" */
 	/* -j heading: */
 	/* " Su  Mo  Tu  We  Th  Fr  Sa" */
-	char day_headings[ENABLE_FEATURE_ASSUME_UNICODE ? 28 * 6 : 28];
-	IF_FEATURE_ASSUME_UNICODE(char *hp = day_headings;)
+	char day_headings[ENABLE_UNICODE_SUPPORT ? 28 * 6 : 28];
+	IF_UNICODE_SUPPORT(char *hp = day_headings;)
 	char buf[40];
 
 	init_unicode();
@@ -134,7 +134,7 @@ int cal_main(int argc UNUSED_PARAM, char **argv)
 			zero_tm.tm_wday = i;
 			/* abbreviated weekday name according to locale */
 			strftime(buf, sizeof(buf), "%a", &zero_tm);
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 			if (julian)
 				*hp++ = ' ';
 			{
@@ -149,7 +149,7 @@ int cal_main(int argc UNUSED_PARAM, char **argv)
 #endif
 		}
 	} while (++i < 12);
-	IF_FEATURE_ASSUME_UNICODE(hp[-1] = '\0';)
+	IF_UNICODE_SUPPORT(hp[-1] = '\0';)
 
 	if (month) {
 		unsigned row, len, days[MAXDAYS];
diff --git a/coreutils/df.c b/coreutils/df.c
index 4b23faa7a..5eeb5b476 100644
--- a/coreutils/df.c
+++ b/coreutils/df.c
@@ -174,7 +174,7 @@ int df_main(int argc UNUSED_PARAM, char **argv)
 			}
 #endif
 
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 			{
 				uni_stat_t uni_stat;
 				char *uni_dev = unicode_conv_to_printable(&uni_stat, device);
diff --git a/coreutils/expand.c b/coreutils/expand.c
index cfb1e25d9..b874b6ad4 100644
--- a/coreutils/expand.c
+++ b/coreutils/expand.c
@@ -48,7 +48,7 @@ static void expand(FILE *file, unsigned tab_size, unsigned opt)
 			if (c == '\t') {
 				unsigned len;
 				*ptr = '\0';
-# if ENABLE_FEATURE_ASSUME_UNICODE
+# if ENABLE_UNICODE_SUPPORT
 				{
 					uni_stat_t uni_stat;
 					printable_string(&uni_stat, ptr_strbeg);
@@ -107,7 +107,7 @@ static void unexpand(FILE *file, unsigned tab_size, unsigned opt)
 			}
 			n = strcspn(ptr, "\t ");
 			printf("%*s%.*s", len, "", n, ptr);
-# if ENABLE_FEATURE_ASSUME_UNICODE
+# if ENABLE_UNICODE_SUPPORT
 			{
 				char c;
 				uni_stat_t uni_stat;
diff --git a/include/unicode.h b/include/unicode.h
index deb4022c3..4e2927297 100644
--- a/include/unicode.h
+++ b/include/unicode.h
@@ -5,7 +5,7 @@
 #ifndef UNICODE_H
 #define UNICODE_H 1
 
-#if ENABLE_LOCALE_SUPPORT
+#if ENABLE_UNICODE_USING_LOCALE
 # include <wchar.h>
 # include <wctype.h>
 #endif
@@ -21,7 +21,7 @@ enum {
 #define unicode_bidi_isrtl(wc) 0
 #define unicode_bidi_is_neutral_wchar(wc) (wc <= 126 && !isalpha(wc))
 
-#if !ENABLE_FEATURE_ASSUME_UNICODE
+#if !ENABLE_UNICODE_SUPPORT
 
 # define unicode_strlen(string) strlen(string)
 # define unicode_status UNICODE_OFF
@@ -50,7 +50,7 @@ char* FAST_FUNC unicode_conv_to_printable(uni_stat_t *stats, const char *src);
 char* FAST_FUNC unicode_conv_to_printable_maxwidth(uni_stat_t *stats, const char *src, unsigned maxwidth);
 char* FAST_FUNC unicode_conv_to_printable_fixedwidth(uni_stat_t *stats, const char *src, unsigned width);
 
-# if ENABLE_LOCALE_SUPPORT
+# if ENABLE_UNICODE_USING_LOCALE
 
 extern uint8_t unicode_status;
 void init_unicode(void) FAST_FUNC;
@@ -102,9 +102,9 @@ int unicode_bidi_is_neutral_wchar(wint_t wc) FAST_FUNC;
 #  endif
 
 
-# endif /* !LOCALE_SUPPORT */
+# endif /* !UNICODE_USING_LOCALE */
 
-#endif /* FEATURE_ASSUME_UNICODE */
+#endif /* UNICODE_SUPPORT */
 
 POP_SAVED_FUNCTION_VISIBILITY
 
diff --git a/libbb/Kbuild b/libbb/Kbuild
index 49cf4b8ad..4606d5aa7 100644
--- a/libbb/Kbuild
+++ b/libbb/Kbuild
@@ -124,7 +124,7 @@ lib-y += xrealloc_vector.o
 # and objects which may fail to build (SELinux on selinux-less system)
 lib-$(CONFIG_SELINUX) += selinux_common.o
 lib-$(CONFIG_FEATURE_MTAB_SUPPORT) += mtab.o
-lib-$(CONFIG_FEATURE_ASSUME_UNICODE) += unicode.o
+lib-$(CONFIG_UNICODE_SUPPORT) += unicode.o
 lib-$(CONFIG_FEATURE_CHECK_NAMES) += die_if_bad_username.o
 
 lib-$(CONFIG_LOSETUP) += loop.o
diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index 38a09cb26..dc90846f9 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -67,7 +67,7 @@
 
 
 #undef CHAR_T
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 # define BB_NUL L'\0'
 # define CHAR_T wchar_t
 static bool BB_isspace(CHAR_T c) { return ((unsigned)c < 256 && isspace(c)); }
@@ -202,7 +202,7 @@ static void deinit_S(void)
 #define DEINIT_S() deinit_S()
 
 
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 static size_t load_string(const char *src, int maxsize)
 {
 	ssize_t len = mbstowcs(command_ps, src, maxsize - 1);
@@ -932,7 +932,7 @@ static void input_tab(smallint *lastWasTab)
 #define matchBuf (S.input_tab__matchBuf)
 		int find_type;
 		int recalc_pos;
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 		/* cursor pos in command converted to multibyte form */
 		int cursor_mb;
 #endif
@@ -942,7 +942,7 @@ static void input_tab(smallint *lastWasTab)
 		/* Make a local copy of the string --
 		 * up to the position of the cursor */
 		save_string(matchBuf, cursor + 1);
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 		cursor_mb = strlen(matchBuf);
 #endif
 		tmp = matchBuf;
@@ -1015,7 +1015,7 @@ static void input_tab(smallint *lastWasTab)
 		}
 
 		len_found = strlen(tmp);
-#if !ENABLE_FEATURE_ASSUME_UNICODE
+#if !ENABLE_UNICODE_SUPPORT
 		/* have space to place the match? */
 		/* The result consists of three parts with these lengths: */
 		/* (cursor - recalc_pos) + len_found + (command_len - cursor) */
@@ -1088,7 +1088,7 @@ static void save_command_ps_at_cur_history(void)
 		int cur = state->cur_history;
 		free(state->history[cur]);
 
-# if ENABLE_FEATURE_ASSUME_UNICODE
+# if ENABLE_UNICODE_SUPPORT
 		{
 			char tbuf[MAX_LINELEN];
 			save_string(tbuf, sizeof(tbuf));
@@ -1659,7 +1659,7 @@ static int lineedit_read_key(char *read_key_buffer)
 {
 	int64_t ic;
 	int timeout = -1;
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 	char unicode_buf[MB_CUR_MAX + 1];
 	int unicode_idx = 0;
 #endif
@@ -1674,7 +1674,7 @@ static int lineedit_read_key(char *read_key_buffer)
 		 */
 		ic = read_key(STDIN_FILENO, read_key_buffer, timeout);
 		if (errno) {
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 			if (errno == EAGAIN && unicode_idx != 0)
 				goto pushback;
 #endif
@@ -1700,7 +1700,7 @@ static int lineedit_read_key(char *read_key_buffer)
 		}
 #endif
 
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 		if (unicode_status == UNICODE_ON) {
 			wchar_t wc;
 
@@ -1817,7 +1817,7 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
 	/* prepare before init handlers */
 	cmdedit_y = 0;  /* quasireal y, not true if line > xt*yt */
 	command_len = 0;
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 	command_ps = xzalloc(maxsize * sizeof(command_ps[0]));
 #else
 	command_ps = command;
@@ -2199,8 +2199,8 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
 //				}
 //			}
 			if (ic < ' '
-			 || (!ENABLE_FEATURE_ASSUME_UNICODE && ic >= 256)
-			 || (ENABLE_FEATURE_ASSUME_UNICODE && ic >= VI_CMDMODE_BIT)
+			 || (!ENABLE_UNICODE_SUPPORT && ic >= 256)
+			 || (ENABLE_UNICODE_SUPPORT && ic >= VI_CMDMODE_BIT)
 			) {
 				/* If VI_CMDMODE_BIT is set, ic is >= 256
 				 * and vi mode ignores unexpected chars.
@@ -2268,7 +2268,7 @@ int FAST_FUNC read_line_input(const char *prompt, char *command, int maxsize, li
 /* Stop bug catching using "command_must_not_be_used" trick */
 #undef command
 
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 	command[0] = '\0';
 	if (command_len > 0)
 		command_len = save_string(command, maxsize - 1);
diff --git a/libbb/printable_string.c b/libbb/printable_string.c
index 47565de0d..83a482196 100644
--- a/libbb/printable_string.c
+++ b/libbb/printable_string.c
@@ -36,7 +36,7 @@ const char* FAST_FUNC printable_string(uni_stat_t *stats, const char *str)
 		s++;
 	}
 
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 	dst = unicode_conv_to_printable(stats, str);
 #else
 	{
diff --git a/libbb/progress.c b/libbb/progress.c
index 0e484da6c..e96039042 100644
--- a/libbb/progress.c
+++ b/libbb/progress.c
@@ -78,7 +78,7 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p,
 		if (ratio > 100) ratio = 100;
 	}
 
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 	init_unicode();
 	/* libbb candidate? */
 	{
diff --git a/libbb/unicode.c b/libbb/unicode.c
index bc9714562..83e70b412 100644
--- a/libbb/unicode.c
+++ b/libbb/unicode.c
@@ -14,12 +14,12 @@
 uint8_t unicode_status;
 #endif
 
-/* This file is compiled only if FEATURE_ASSUME_UNICODE is on.
+/* This file is compiled only if UNICODE_SUPPORT is on.
  * We check other options and decide whether to use libc support
  * via locale, or use our own logic:
  */
 
-#if ENABLE_LOCALE_SUPPORT
+#if ENABLE_UNICODE_USING_LOCALE
 
 /* Unicode support using libc locale support. */
 
@@ -139,7 +139,7 @@ size_t FAST_FUNC wcstombs(char *dest, const wchar_t *src, size_t n)
 	return org_n - n;
 }
 
-#define ERROR_WCHAR (~(wchar_t)0)
+# define ERROR_WCHAR (~(wchar_t)0)
 
 static const char *mbstowc_internal(wchar_t *res, const char *src)
 {
@@ -239,7 +239,427 @@ int FAST_FUNC iswpunct(wint_t wc)
 	return (unsigned)wc <= 0x7f && ispunct(wc);
 }
 
-#include "unicode_wcwidth.c"
+
+# if LAST_SUPPORTED_WCHAR >= 0x300
+struct interval {
+	uint16_t first;
+	uint16_t last;
+};
+
+/* auxiliary function for binary search in interval table */
+static int in_interval_table(unsigned ucs, const struct interval *table, unsigned max)
+{
+	unsigned min;
+	unsigned mid;
+
+	if (ucs < table[0].first || ucs > table[max].last)
+		return 0;
+
+	min = 0;
+	while (max >= min) {
+		mid = (min + max) / 2;
+		if (ucs > table[mid].last)
+			min = mid + 1;
+		else if (ucs < table[mid].first)
+			max = mid - 1;
+		else
+			return 1;
+	}
+	return 0;
+}
+
+static int in_uint16_table(unsigned ucs, const uint16_t *table, unsigned max)
+{
+	unsigned min;
+	unsigned mid;
+	unsigned first, last;
+
+	first = table[0] >> 2;
+	last = first + (table[0] & 3);
+	if (ucs < first || ucs > last)
+		return 0;
+
+	min = 0;
+	while (max >= min) {
+		mid = (min + max) / 2;
+		first = table[mid] >> 2;
+		last = first + (table[mid] & 3);
+		if (ucs > last)
+			min = mid + 1;
+		else if (ucs < first)
+			max = mid - 1;
+		else
+			return 1;
+	}
+	return 0;
+}
+# endif
+
+
+/*
+ * This is an implementation of wcwidth() and wcswidth() (defined in
+ * IEEE Std 1002.1-2001) for Unicode.
+ *
+ * http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html
+ * http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html
+ *
+ * In fixed-width output devices, Latin characters all occupy a single
+ * "cell" position of equal width, whereas ideographic CJK characters
+ * occupy two such cells. Interoperability between terminal-line
+ * applications and (teletype-style) character terminals using the
+ * UTF-8 encoding requires agreement on which character should advance
+ * the cursor by how many cell positions. No established formal
+ * standards exist at present on which Unicode character shall occupy
+ * how many cell positions on character terminals. These routines are
+ * a first attempt of defining such behavior based on simple rules
+ * applied to data provided by the Unicode Consortium.
+ *
+ * For some graphical characters, the Unicode standard explicitly
+ * defines a character-cell width via the definition of the East Asian
+ * FullWidth (F), Wide (W), Half-width (H), and Narrow (Na) classes.
+ * In all these cases, there is no ambiguity about which width a
+ * terminal shall use. For characters in the East Asian Ambiguous (A)
+ * class, the width choice depends purely on a preference of backward
+ * compatibility with either historic CJK or Western practice.
+ * Choosing single-width for these characters is easy to justify as
+ * the appropriate long-term solution, as the CJK practice of
+ * displaying these characters as double-width comes from historic
+ * implementation simplicity (8-bit encoded characters were displayed
+ * single-width and 16-bit ones double-width, even for Greek,
+ * Cyrillic, etc.) and not any typographic considerations.
+ *
+ * Much less clear is the choice of width for the Not East Asian
+ * (Neutral) class. Existing practice does not dictate a width for any
+ * of these characters. It would nevertheless make sense
+ * typographically to allocate two character cells to characters such
+ * as for instance EM SPACE or VOLUME INTEGRAL, which cannot be
+ * represented adequately with a single-width glyph. The following
+ * routines at present merely assign a single-cell width to all
+ * neutral characters, in the interest of simplicity. This is not
+ * entirely satisfactory and should be reconsidered before
+ * establishing a formal standard in this area. At the moment, the
+ * decision which Not East Asian (Neutral) characters should be
+ * represented by double-width glyphs cannot yet be answered by
+ * applying a simple rule from the Unicode database content. Setting
+ * up a proper standard for the behavior of UTF-8 character terminals
+ * will require a careful analysis not only of each Unicode character,
+ * but also of each presentation form, something the author of these
+ * routines has avoided to do so far.
+ *
+ * http://www.unicode.org/unicode/reports/tr11/
+ *
+ * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
+ *
+ * Permission to use, copy, modify, and distribute this software
+ * for any purpose and without fee is hereby granted. The author
+ * disclaims all warranties with regard to this software.
+ *
+ * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
+ */
+
+/* Assigned Unicode character ranges:
+ * Plane Range
+ * 0       0000–FFFF   Basic Multilingual Plane
+ * 1      10000–1FFFF  Supplementary Multilingual Plane
+ * 2      20000–2FFFF  Supplementary Ideographic Plane
+ * 3      30000-3FFFF  Tertiary Ideographic Plane (no chars assigned yet)
+ * 4-13   40000–DFFFF  currently unassigned
+ * 14     E0000–EFFFF  Supplementary Special-purpose Plane
+ * 15     F0000–FFFFF  Supplementary Private Use Area-A
+ * 16    100000–10FFFF Supplementary Private Use Area-B
+ *
+ * "Supplementary Special-purpose Plane currently contains non-graphical
+ * characters in two blocks of 128 and 240 characters. The first block
+ * is for language tag characters for use when language cannot be indicated
+ * through other protocols (such as the xml:lang  attribute in XML).
+ * The other block contains glyph variation selectors to indicate
+ * an alternate glyph for a character that cannot be determined by context."
+ *
+ * In simpler terms: it is a tool to fix the "Han unification" mess
+ * created by Unicode committee, to select Chinese/Japanese/Korean/Taiwan
+ * version of a character. (They forgot that the whole purpose of the Unicode
+ * was to be able to write all chars in one charset without such tricks).
+ * Until East Asian users say it is actually necessary to support these
+ * code points in console applications like busybox
+ * (i.e. do these chars ever appear in filenames, hostnames, text files
+ * and such?), we are treating these code points as invalid.
+ *
+ * Tertiary Ideographic Plane is also ignored for now,
+ * until Unicode committee assigns something there.
+ */
+/* The following two functions define the column width of an ISO 10646
+ * character as follows:
+ *
+ *    - The null character (U+0000) has a column width of 0.
+ *
+ *    - Other C0/C1 control characters and DEL will lead to a return
+ *      value of -1.
+ *
+ *    - Non-spacing and enclosing combining characters (general
+ *      category code Mn or Me in the Unicode database) have a
+ *      column width of 0.
+ *
+ *    - SOFT HYPHEN (U+00AD) has a column width of 1.
+ *
+ *    - Other format characters (general category code Cf in the Unicode
+ *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
+ *
+ *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
+ *      have a column width of 0.
+ *
+ *    - Spacing characters in the East Asian Wide (W) or East Asian
+ *      Full-width (F) category as defined in Unicode Technical
+ *      Report #11 have a column width of 2.
+ *
+ *    - All remaining characters (including all printable
+ *      ISO 8859-1 and WGL4 characters, Unicode control characters,
+ *      etc.) have a column width of 1.
+ *
+ * This implementation assumes that wchar_t characters are encoded
+ * in ISO 10646.
+ */
+static int wcwidth(unsigned ucs)
+{
+# if LAST_SUPPORTED_WCHAR >= 0x300
+	/* sorted list of non-overlapping intervals of non-spacing characters */
+	/* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
+	static const struct interval combining[] = {
+#  define BIG_(a,b) { a, b },
+#  define PAIR(a,b)
+#  define ARRAY /* PAIR if < 0x4000 and no more than 4 chars big */ \
+		BIG_(0x0300, 0x036F) \
+		PAIR(0x0483, 0x0486) \
+		PAIR(0x0488, 0x0489) \
+		BIG_(0x0591, 0x05BD) \
+		PAIR(0x05BF, 0x05BF) \
+		PAIR(0x05C1, 0x05C2) \
+		PAIR(0x05C4, 0x05C5) \
+		PAIR(0x05C7, 0x05C7) \
+		PAIR(0x0600, 0x0603) \
+		BIG_(0x0610, 0x0615) \
+		BIG_(0x064B, 0x065E) \
+		PAIR(0x0670, 0x0670) \
+		BIG_(0x06D6, 0x06E4) \
+		PAIR(0x06E7, 0x06E8) \
+		PAIR(0x06EA, 0x06ED) \
+		PAIR(0x070F, 0x070F) \
+		PAIR(0x0711, 0x0711) \
+		BIG_(0x0730, 0x074A) \
+		BIG_(0x07A6, 0x07B0) \
+		BIG_(0x07EB, 0x07F3) \
+		PAIR(0x0901, 0x0902) \
+		PAIR(0x093C, 0x093C) \
+		BIG_(0x0941, 0x0948) \
+		PAIR(0x094D, 0x094D) \
+		PAIR(0x0951, 0x0954) \
+		PAIR(0x0962, 0x0963) \
+		PAIR(0x0981, 0x0981) \
+		PAIR(0x09BC, 0x09BC) \
+		PAIR(0x09C1, 0x09C4) \
+		PAIR(0x09CD, 0x09CD) \
+		PAIR(0x09E2, 0x09E3) \
+		PAIR(0x0A01, 0x0A02) \
+		PAIR(0x0A3C, 0x0A3C) \
+		PAIR(0x0A41, 0x0A42) \
+		PAIR(0x0A47, 0x0A48) \
+		PAIR(0x0A4B, 0x0A4D) \
+		PAIR(0x0A70, 0x0A71) \
+		PAIR(0x0A81, 0x0A82) \
+		PAIR(0x0ABC, 0x0ABC) \
+		BIG_(0x0AC1, 0x0AC5) \
+		PAIR(0x0AC7, 0x0AC8) \
+		PAIR(0x0ACD, 0x0ACD) \
+		PAIR(0x0AE2, 0x0AE3) \
+		PAIR(0x0B01, 0x0B01) \
+		PAIR(0x0B3C, 0x0B3C) \
+		PAIR(0x0B3F, 0x0B3F) \
+		PAIR(0x0B41, 0x0B43) \
+		PAIR(0x0B4D, 0x0B4D) \
+		PAIR(0x0B56, 0x0B56) \
+		PAIR(0x0B82, 0x0B82) \
+		PAIR(0x0BC0, 0x0BC0) \
+		PAIR(0x0BCD, 0x0BCD) \
+		PAIR(0x0C3E, 0x0C40) \
+		PAIR(0x0C46, 0x0C48) \
+		PAIR(0x0C4A, 0x0C4D) \
+		PAIR(0x0C55, 0x0C56) \
+		PAIR(0x0CBC, 0x0CBC) \
+		PAIR(0x0CBF, 0x0CBF) \
+		PAIR(0x0CC6, 0x0CC6) \
+		PAIR(0x0CCC, 0x0CCD) \
+		PAIR(0x0CE2, 0x0CE3) \
+		PAIR(0x0D41, 0x0D43) \
+		PAIR(0x0D4D, 0x0D4D) \
+		PAIR(0x0DCA, 0x0DCA) \
+		PAIR(0x0DD2, 0x0DD4) \
+		PAIR(0x0DD6, 0x0DD6) \
+		PAIR(0x0E31, 0x0E31) \
+		BIG_(0x0E34, 0x0E3A) \
+		BIG_(0x0E47, 0x0E4E) \
+		PAIR(0x0EB1, 0x0EB1) \
+		BIG_(0x0EB4, 0x0EB9) \
+		PAIR(0x0EBB, 0x0EBC) \
+		BIG_(0x0EC8, 0x0ECD) \
+		PAIR(0x0F18, 0x0F19) \
+		PAIR(0x0F35, 0x0F35) \
+		PAIR(0x0F37, 0x0F37) \
+		PAIR(0x0F39, 0x0F39) \
+		BIG_(0x0F71, 0x0F7E) \
+		BIG_(0x0F80, 0x0F84) \
+		PAIR(0x0F86, 0x0F87) \
+		PAIR(0x0FC6, 0x0FC6) \
+		BIG_(0x0F90, 0x0F97) \
+		BIG_(0x0F99, 0x0FBC) \
+		PAIR(0x102D, 0x1030) \
+		PAIR(0x1032, 0x1032) \
+		PAIR(0x1036, 0x1037) \
+		PAIR(0x1039, 0x1039) \
+		PAIR(0x1058, 0x1059) \
+		BIG_(0x1160, 0x11FF) \
+		PAIR(0x135F, 0x135F) \
+		PAIR(0x1712, 0x1714) \
+		PAIR(0x1732, 0x1734) \
+		PAIR(0x1752, 0x1753) \
+		PAIR(0x1772, 0x1773) \
+		PAIR(0x17B4, 0x17B5) \
+		BIG_(0x17B7, 0x17BD) \
+		PAIR(0x17C6, 0x17C6) \
+		BIG_(0x17C9, 0x17D3) \
+		PAIR(0x17DD, 0x17DD) \
+		PAIR(0x180B, 0x180D) \
+		PAIR(0x18A9, 0x18A9) \
+		PAIR(0x1920, 0x1922) \
+		PAIR(0x1927, 0x1928) \
+		PAIR(0x1932, 0x1932) \
+		PAIR(0x1939, 0x193B) \
+		PAIR(0x1A17, 0x1A18) \
+		PAIR(0x1B00, 0x1B03) \
+		PAIR(0x1B34, 0x1B34) \
+		BIG_(0x1B36, 0x1B3A) \
+		PAIR(0x1B3C, 0x1B3C) \
+		PAIR(0x1B42, 0x1B42) \
+		BIG_(0x1B6B, 0x1B73) \
+		BIG_(0x1DC0, 0x1DCA) \
+		PAIR(0x1DFE, 0x1DFF) \
+		BIG_(0x200B, 0x200F) \
+		BIG_(0x202A, 0x202E) \
+		PAIR(0x2060, 0x2063) \
+		BIG_(0x206A, 0x206F) \
+		BIG_(0x20D0, 0x20EF) \
+		BIG_(0x302A, 0x302F) \
+		PAIR(0x3099, 0x309A) \
+		/* Too big to be packed in PAIRs: */ \
+		BIG_(0xA806, 0xA806) \
+		BIG_(0xA80B, 0xA80B) \
+		BIG_(0xA825, 0xA826) \
+		BIG_(0xFB1E, 0xFB1E) \
+		BIG_(0xFE00, 0xFE0F) \
+		BIG_(0xFE20, 0xFE23) \
+		BIG_(0xFEFF, 0xFEFF) \
+		BIG_(0xFFF9, 0xFFFB)
+		ARRAY
+#  undef BIG_
+#  undef PAIR
+	};
+#  define BIG_(a,b)
+#  define PAIR(a,b) (a << 2) | (b-a),
+	static const uint16_t combining1[] = { ARRAY };
+#  undef BIG_
+#  undef PAIR
+#  define BIG_(a,b) char big_##a[b < 0x4000 && b-a <= 3 ? -1 : 1];
+#  define PAIR(a,b) char pair##a[b >= 0x4000 || b-a > 3 ? -1 : 1];
+	struct CHECK { ARRAY };
+#  undef BIG_
+#  undef PAIR
+#  undef ARRAY
+# endif
+
+	if (ucs == 0)
+		return 0;
+
+	/* Test for 8-bit control characters (00-1f, 80-9f, 7f) */
+	if ((ucs & ~0x80) < 0x20 || ucs == 0x7f)
+		return -1;
+	/* Quick abort if it is an obviously invalid char */
+	if (ucs > LAST_SUPPORTED_WCHAR)
+		return -1;
+
+	/* Optimization: no combining chars below 0x300 */
+	if (LAST_SUPPORTED_WCHAR < 0x300 || ucs < 0x300)
+		return 1;
+
+# if LAST_SUPPORTED_WCHAR >= 0x300
+	/* Binary search in table of non-spacing characters */
+	if (in_interval_table(ucs, combining, ARRAY_SIZE(combining) - 1))
+		return 0;
+	if (in_uint16_table(ucs, combining1, ARRAY_SIZE(combining1) - 1))
+		return 0;
+
+	/* Optimization: all chars below 0x1100 are not double-width */
+	if (LAST_SUPPORTED_WCHAR < 0x1100 || ucs < 0x1100)
+		return 1;
+
+#  if LAST_SUPPORTED_WCHAR >= 0x1100
+	/* Invalid code points: */
+	/* High (d800..dbff) and low (dc00..dfff) surrogates (valid only in UTF16) */
+	/* Private Use Area (e000..f8ff) */
+	/* Noncharacters fdd0..fdef */
+	if ((LAST_SUPPORTED_WCHAR >= 0xd800 && ucs >= 0xd800 && ucs <= 0xf8ff)
+	 || (LAST_SUPPORTED_WCHAR >= 0xfdd0 && ucs >= 0xfdd0 && ucs <= 0xfdef)
+	) {
+		return -1;
+	}
+	/* 0xfffe and 0xffff in every plane are invalid */
+	if (LAST_SUPPORTED_WCHAR >= 0xfffe && ((ucs & 0xfffe) == 0xfffe)) {
+		return -1;
+	}
+
+#   if LAST_SUPPORTED_WCHAR >= 0x10000
+	if (ucs >= 0x10000) {
+		/* Combining chars in Supplementary Multilingual Plane 0x1xxxx */
+		static const struct interval combining0x10000[] = {
+			{ 0x0A01, 0x0A03 }, { 0x0A05, 0x0A06 }, { 0x0A0C, 0x0A0F },
+			{ 0x0A38, 0x0A3A }, { 0x0A3F, 0x0A3F }, { 0xD167, 0xD169 },
+			{ 0xD173, 0xD182 }, { 0xD185, 0xD18B }, { 0xD1AA, 0xD1AD },
+			{ 0xD242, 0xD244 }
+		};
+		/* Binary search in table of non-spacing characters in Supplementary Multilingual Plane */
+		if (in_interval_table(ucs ^ 0x10000, combining0x10000, ARRAY_SIZE(combining0x10000) - 1))
+			return 0;
+		/* Check a few non-spacing chars in Supplementary Special-purpose Plane 0xExxxx */
+		if (LAST_SUPPORTED_WCHAR >= 0xE0001
+		 && (  ucs == 0xE0001
+		    || (ucs >= 0xE0020 && ucs <= 0xE007F)
+		    || (ucs >= 0xE0100 && ucs <= 0xE01EF)
+		    )
+		) {
+			return 0;
+		}
+	}
+#   endif
+
+	/* If we arrive here, ucs is not a combining or C0/C1 control character.
+	 * Check whether it's 1 char or 2-shar wide.
+	 */
+	return 1 +
+		(  (/*ucs >= 0x1100 &&*/ ucs <= 0x115f) /* Hangul Jamo init. consonants */
+		|| ucs == 0x2329 /* left-pointing angle bracket; also CJK punct. char */
+		|| ucs == 0x232a /* right-pointing angle bracket; also CJK punct. char */
+		|| (ucs >= 0x2e80 && ucs <= 0xa4cf && ucs != 0x303f) /* CJK ... Yi */
+#   if LAST_SUPPORTED_WCHAR >= 0xac00
+		|| (ucs >= 0xac00 && ucs <= 0xd7a3) /* Hangul Syllables */
+		|| (ucs >= 0xf900 && ucs <= 0xfaff) /* CJK Compatibility Ideographs */
+		|| (ucs >= 0xfe10 && ucs <= 0xfe19) /* Vertical forms */
+		|| (ucs >= 0xfe30 && ucs <= 0xfe6f) /* CJK Compatibility Forms */
+		|| (ucs >= 0xff00 && ucs <= 0xff60) /* Fullwidth Forms */
+		|| (ucs >= 0xffe0 && ucs <= 0xffe6)
+		|| ((ucs >> 17) == (2 >> 1)) /* 20000..3ffff: Supplementary and Tertiary Ideographic Planes */
+#   endif
+		);
+#  endif /* >= 0x1100 */
+# endif /* >= 0x300 */
+}
+
 
 # if ENABLE_UNICODE_BIDI_SUPPORT
 int FAST_FUNC unicode_bidi_isrtl(wint_t wc)
@@ -592,7 +1012,7 @@ static char* FAST_FUNC unicode_conv_to_printable2(uni_stat_t *stats, const char
 		int w;
 		wchar_t wc;
 
-#if ENABLE_LOCALE_SUPPORT
+#if ENABLE_UNICODE_USING_LOCALE
 		{
 			mbstate_t mbst = { 0 };
 			ssize_t rc = mbsrtowcs(&wc, &src, 1, &mbst);
@@ -647,7 +1067,7 @@ static char* FAST_FUNC unicode_conv_to_printable2(uni_stat_t *stats, const char
 		uni_count++;
 		uni_width += w;
 		dst = xrealloc(dst, dst_len + MB_CUR_MAX);
-#if ENABLE_LOCALE_SUPPORT
+#if ENABLE_UNICODE_USING_LOCALE
 		{
 			mbstate_t mbst = { 0 };
 			dst_len += wcrtomb(&dst[dst_len], wc, &mbst);
@@ -699,7 +1119,7 @@ unsigned FAST_FUNC unicode_padding_to_width(unsigned width, const char *src)
 		int w;
 		wchar_t wc;
 
-#if ENABLE_LOCALE_SUPPORT
+#if ENABLE_UNICODE_USING_LOCALE
 		{
 			mbstate_t mbst = { 0 };
 			ssize_t rc = mbsrtowcs(&wc, &src, 1, &mbst);
diff --git a/libbb/unicode_wcwidth.c b/libbb/unicode_wcwidth.c
deleted file mode 100644
index 0bb622705..000000000
--- a/libbb/unicode_wcwidth.c
+++ /dev/null
@@ -1,543 +0,0 @@
-/*
- * This is an implementation of wcwidth() and wcswidth() (defined in
- * IEEE Std 1002.1-2001) for Unicode.
- *
- * http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html
- * http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html
- *
- * In fixed-width output devices, Latin characters all occupy a single
- * "cell" position of equal width, whereas ideographic CJK characters
- * occupy two such cells. Interoperability between terminal-line
- * applications and (teletype-style) character terminals using the
- * UTF-8 encoding requires agreement on which character should advance
- * the cursor by how many cell positions. No established formal
- * standards exist at present on which Unicode character shall occupy
- * how many cell positions on character terminals. These routines are
- * a first attempt of defining such behavior based on simple rules
- * applied to data provided by the Unicode Consortium.
- *
- * For some graphical characters, the Unicode standard explicitly
- * defines a character-cell width via the definition of the East Asian
- * FullWidth (F), Wide (W), Half-width (H), and Narrow (Na) classes.
- * In all these cases, there is no ambiguity about which width a
- * terminal shall use. For characters in the East Asian Ambiguous (A)
- * class, the width choice depends purely on a preference of backward
- * compatibility with either historic CJK or Western practice.
- * Choosing single-width for these characters is easy to justify as
- * the appropriate long-term solution, as the CJK practice of
- * displaying these characters as double-width comes from historic
- * implementation simplicity (8-bit encoded characters were displayed
- * single-width and 16-bit ones double-width, even for Greek,
- * Cyrillic, etc.) and not any typographic considerations.
- *
- * Much less clear is the choice of width for the Not East Asian
- * (Neutral) class. Existing practice does not dictate a width for any
- * of these characters. It would nevertheless make sense
- * typographically to allocate two character cells to characters such
- * as for instance EM SPACE or VOLUME INTEGRAL, which cannot be
- * represented adequately with a single-width glyph. The following
- * routines at present merely assign a single-cell width to all
- * neutral characters, in the interest of simplicity. This is not
- * entirely satisfactory and should be reconsidered before
- * establishing a formal standard in this area. At the moment, the
- * decision which Not East Asian (Neutral) characters should be
- * represented by double-width glyphs cannot yet be answered by
- * applying a simple rule from the Unicode database content. Setting
- * up a proper standard for the behavior of UTF-8 character terminals
- * will require a careful analysis not only of each Unicode character,
- * but also of each presentation form, something the author of these
- * routines has avoided to do so far.
- *
- * http://www.unicode.org/unicode/reports/tr11/
- *
- * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
- *
- * Permission to use, copy, modify, and distribute this software
- * for any purpose and without fee is hereby granted. The author
- * disclaims all warranties with regard to this software.
- *
- * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
- */
-
-/* Assigned Unicode character ranges:
- * Plane Range
- * 0       0000–FFFF   Basic Multilingual Plane
- * 1      10000–1FFFF  Supplementary Multilingual Plane
- * 2      20000–2FFFF  Supplementary Ideographic Plane
- * 3      30000-3FFFF  Tertiary Ideographic Plane (no chars assigned yet)
- * 4-13   40000–DFFFF  currently unassigned
- * 14     E0000–EFFFF  Supplementary Special-purpose Plane
- * 15     F0000–FFFFF  Supplementary Private Use Area-A
- * 16    100000–10FFFF Supplementary Private Use Area-B
- *
- * "Supplementary Special-purpose Plane currently contains non-graphical
- * characters in two blocks of 128 and 240 characters. The first block
- * is for language tag characters for use when language cannot be indicated
- * through other protocols (such as the xml:lang  attribute in XML).
- * The other block contains glyph variation selectors to indicate
- * an alternate glyph for a character that cannot be determined by context."
- *
- * In simpler terms: it is a tool to fix the "Han unification" mess
- * created by Unicode committee, to select Chinese/Japanese/Korean/Taiwan
- * version of a character. (They forgot that the whole purpose of the Unicode
- * was to be able to write all chars in one charset without such tricks).
- * Until East Asian users say it is actually necessary to support these
- * code points in console applications like busybox
- * (i.e. do these chars ever appear in filenames, hostnames, text files
- * and such?), we are treating these code points as invalid.
- *
- * Tertiary Ideographic Plane is also ignored for now,
- * until Unicode committee assigns something there.
- */
-
-#if LAST_SUPPORTED_WCHAR >= 0x300
-struct interval {
-	uint16_t first;
-	uint16_t last;
-};
-
-/* auxiliary function for binary search in interval table */
-static int in_interval_table(unsigned ucs, const struct interval *table, unsigned max)
-{
-	unsigned min;
-	unsigned mid;
-
-	if (ucs < table[0].first || ucs > table[max].last)
-		return 0;
-
-	min = 0;
-	while (max >= min) {
-		mid = (min + max) / 2;
-		if (ucs > table[mid].last)
-			min = mid + 1;
-		else if (ucs < table[mid].first)
-			max = mid - 1;
-		else
-			return 1;
-	}
-	return 0;
-}
-
-static int in_uint16_table(unsigned ucs, const uint16_t *table, unsigned max)
-{
-	unsigned min;
-	unsigned mid;
-	unsigned first, last;
-
-	first = table[0] >> 2;
-	last = first + (table[0] & 3);
-	if (ucs < first || ucs > last)
-		return 0;
-
-	min = 0;
-	while (max >= min) {
-		mid = (min + max) / 2;
-		first = table[mid] >> 2;
-		last = first + (table[mid] & 3);
-		if (ucs > last)
-			min = mid + 1;
-		else if (ucs < first)
-			max = mid - 1;
-		else
-			return 1;
-	}
-	return 0;
-}
-#endif
-
-
-/* The following two functions define the column width of an ISO 10646
- * character as follows:
- *
- *    - The null character (U+0000) has a column width of 0.
- *
- *    - Other C0/C1 control characters and DEL will lead to a return
- *      value of -1.
- *
- *    - Non-spacing and enclosing combining characters (general
- *      category code Mn or Me in the Unicode database) have a
- *      column width of 0.
- *
- *    - SOFT HYPHEN (U+00AD) has a column width of 1.
- *
- *    - Other format characters (general category code Cf in the Unicode
- *      database) and ZERO WIDTH SPACE (U+200B) have a column width of 0.
- *
- *    - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF)
- *      have a column width of 0.
- *
- *    - Spacing characters in the East Asian Wide (W) or East Asian
- *      Full-width (F) category as defined in Unicode Technical
- *      Report #11 have a column width of 2.
- *
- *    - All remaining characters (including all printable
- *      ISO 8859-1 and WGL4 characters, Unicode control characters,
- *      etc.) have a column width of 1.
- *
- * This implementation assumes that wchar_t characters are encoded
- * in ISO 10646.
- */
-static int wcwidth(unsigned ucs)
-{
-#if LAST_SUPPORTED_WCHAR >= 0x300
-	/* sorted list of non-overlapping intervals of non-spacing characters */
-	/* generated by "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c" */
-	static const struct interval combining[] = {
-#define BIG_(a,b) { a, b },
-#define PAIR(a,b)
-		/* PAIR if < 0x4000 and no more than 4 chars big */
-		BIG_(0x0300, 0x036F)
-		PAIR(0x0483, 0x0486)
-		PAIR(0x0488, 0x0489)
-		BIG_(0x0591, 0x05BD)
-		PAIR(0x05BF, 0x05BF)
-		PAIR(0x05C1, 0x05C2)
-		PAIR(0x05C4, 0x05C5)
-		PAIR(0x05C7, 0x05C7)
-		PAIR(0x0600, 0x0603)
-		BIG_(0x0610, 0x0615)
-		BIG_(0x064B, 0x065E)
-		PAIR(0x0670, 0x0670)
-		BIG_(0x06D6, 0x06E4)
-		PAIR(0x06E7, 0x06E8)
-		PAIR(0x06EA, 0x06ED)
-		PAIR(0x070F, 0x070F)
-		PAIR(0x0711, 0x0711)
-		BIG_(0x0730, 0x074A)
-		BIG_(0x07A6, 0x07B0)
-		BIG_(0x07EB, 0x07F3)
-		PAIR(0x0901, 0x0902)
-		PAIR(0x093C, 0x093C)
-		BIG_(0x0941, 0x0948)
-		PAIR(0x094D, 0x094D)
-		PAIR(0x0951, 0x0954)
-		PAIR(0x0962, 0x0963)
-		PAIR(0x0981, 0x0981)
-		PAIR(0x09BC, 0x09BC)
-		PAIR(0x09C1, 0x09C4)
-		PAIR(0x09CD, 0x09CD)
-		PAIR(0x09E2, 0x09E3)
-		PAIR(0x0A01, 0x0A02)
-		PAIR(0x0A3C, 0x0A3C)
-		PAIR(0x0A41, 0x0A42)
-		PAIR(0x0A47, 0x0A48)
-		PAIR(0x0A4B, 0x0A4D)
-		PAIR(0x0A70, 0x0A71)
-		PAIR(0x0A81, 0x0A82)
-		PAIR(0x0ABC, 0x0ABC)
-		BIG_(0x0AC1, 0x0AC5)
-		PAIR(0x0AC7, 0x0AC8)
-		PAIR(0x0ACD, 0x0ACD)
-		PAIR(0x0AE2, 0x0AE3)
-		PAIR(0x0B01, 0x0B01)
-		PAIR(0x0B3C, 0x0B3C)
-		PAIR(0x0B3F, 0x0B3F)
-		PAIR(0x0B41, 0x0B43)
-		PAIR(0x0B4D, 0x0B4D)
-		PAIR(0x0B56, 0x0B56)
-		PAIR(0x0B82, 0x0B82)
-		PAIR(0x0BC0, 0x0BC0)
-		PAIR(0x0BCD, 0x0BCD)
-		PAIR(0x0C3E, 0x0C40)
-		PAIR(0x0C46, 0x0C48)
-		PAIR(0x0C4A, 0x0C4D)
-		PAIR(0x0C55, 0x0C56)
-		PAIR(0x0CBC, 0x0CBC)
-		PAIR(0x0CBF, 0x0CBF)
-		PAIR(0x0CC6, 0x0CC6)
-		PAIR(0x0CCC, 0x0CCD)
-		PAIR(0x0CE2, 0x0CE3)
-		PAIR(0x0D41, 0x0D43)
-		PAIR(0x0D4D, 0x0D4D)
-		PAIR(0x0DCA, 0x0DCA)
-		PAIR(0x0DD2, 0x0DD4)
-		PAIR(0x0DD6, 0x0DD6)
-		PAIR(0x0E31, 0x0E31)
-		BIG_(0x0E34, 0x0E3A)
-		BIG_(0x0E47, 0x0E4E)
-		PAIR(0x0EB1, 0x0EB1)
-		BIG_(0x0EB4, 0x0EB9)
-		PAIR(0x0EBB, 0x0EBC)
-		BIG_(0x0EC8, 0x0ECD)
-		PAIR(0x0F18, 0x0F19)
-		PAIR(0x0F35, 0x0F35)
-		PAIR(0x0F37, 0x0F37)
-		PAIR(0x0F39, 0x0F39)
-		BIG_(0x0F71, 0x0F7E)
-		BIG_(0x0F80, 0x0F84)
-		PAIR(0x0F86, 0x0F87)
-		PAIR(0x0FC6, 0x0FC6)
-		BIG_(0x0F90, 0x0F97)
-		BIG_(0x0F99, 0x0FBC)
-		PAIR(0x102D, 0x1030)
-		PAIR(0x1032, 0x1032)
-		PAIR(0x1036, 0x1037)
-		PAIR(0x1039, 0x1039)
-		PAIR(0x1058, 0x1059)
-		BIG_(0x1160, 0x11FF)
-		PAIR(0x135F, 0x135F)
-		PAIR(0x1712, 0x1714)
-		PAIR(0x1732, 0x1734)
-		PAIR(0x1752, 0x1753)
-		PAIR(0x1772, 0x1773)
-		PAIR(0x17B4, 0x17B5)
-		BIG_(0x17B7, 0x17BD)
-		PAIR(0x17C6, 0x17C6)
-		BIG_(0x17C9, 0x17D3)
-		PAIR(0x17DD, 0x17DD)
-		PAIR(0x180B, 0x180D)
-		PAIR(0x18A9, 0x18A9)
-		PAIR(0x1920, 0x1922)
-		PAIR(0x1927, 0x1928)
-		PAIR(0x1932, 0x1932)
-		PAIR(0x1939, 0x193B)
-		PAIR(0x1A17, 0x1A18)
-		PAIR(0x1B00, 0x1B03)
-		PAIR(0x1B34, 0x1B34)
-		BIG_(0x1B36, 0x1B3A)
-		PAIR(0x1B3C, 0x1B3C)
-		PAIR(0x1B42, 0x1B42)
-		BIG_(0x1B6B, 0x1B73)
-		BIG_(0x1DC0, 0x1DCA)
-		PAIR(0x1DFE, 0x1DFF)
-		BIG_(0x200B, 0x200F)
-		BIG_(0x202A, 0x202E)
-		PAIR(0x2060, 0x2063)
-		BIG_(0x206A, 0x206F)
-		BIG_(0x20D0, 0x20EF)
-		BIG_(0x302A, 0x302F)
-		PAIR(0x3099, 0x309A)
-		/* Too big to be packed in PAIRs: */
-		{ 0xA806, 0xA806 },
-		{ 0xA80B, 0xA80B },
-		{ 0xA825, 0xA826 },
-		{ 0xFB1E, 0xFB1E },
-		{ 0xFE00, 0xFE0F },
-		{ 0xFE20, 0xFE23 },
-		{ 0xFEFF, 0xFEFF },
-		{ 0xFFF9, 0xFFFB }
-#undef BIG_
-#undef PAIR
-	};
-	static const uint16_t combining1[] = {
-#define BIG_(a,b)
-#define PAIR(a,b) (a << 2) | (b-a),
-		/* Exact copy-n-paste of the above: */
-		BIG_(0x0300, 0x036F)
-		PAIR(0x0483, 0x0486)
-		PAIR(0x0488, 0x0489)
-		BIG_(0x0591, 0x05BD)
-		PAIR(0x05BF, 0x05BF)
-		PAIR(0x05C1, 0x05C2)
-		PAIR(0x05C4, 0x05C5)
-		PAIR(0x05C7, 0x05C7)
-		PAIR(0x0600, 0x0603)
-		BIG_(0x0610, 0x0615)
-		BIG_(0x064B, 0x065E)
-		PAIR(0x0670, 0x0670)
-		BIG_(0x06D6, 0x06E4)
-		PAIR(0x06E7, 0x06E8)
-		PAIR(0x06EA, 0x06ED)
-		PAIR(0x070F, 0x070F)
-		PAIR(0x0711, 0x0711)
-		BIG_(0x0730, 0x074A)
-		BIG_(0x07A6, 0x07B0)
-		BIG_(0x07EB, 0x07F3)
-		PAIR(0x0901, 0x0902)
-		PAIR(0x093C, 0x093C)
-		BIG_(0x0941, 0x0948)
-		PAIR(0x094D, 0x094D)
-		PAIR(0x0951, 0x0954)
-		PAIR(0x0962, 0x0963)
-		PAIR(0x0981, 0x0981)
-		PAIR(0x09BC, 0x09BC)
-		PAIR(0x09C1, 0x09C4)
-		PAIR(0x09CD, 0x09CD)
-		PAIR(0x09E2, 0x09E3)
-		PAIR(0x0A01, 0x0A02)
-		PAIR(0x0A3C, 0x0A3C)
-		PAIR(0x0A41, 0x0A42)
-		PAIR(0x0A47, 0x0A48)
-		PAIR(0x0A4B, 0x0A4D)
-		PAIR(0x0A70, 0x0A71)
-		PAIR(0x0A81, 0x0A82)
-		PAIR(0x0ABC, 0x0ABC)
-		BIG_(0x0AC1, 0x0AC5)
-		PAIR(0x0AC7, 0x0AC8)
-		PAIR(0x0ACD, 0x0ACD)
-		PAIR(0x0AE2, 0x0AE3)
-		PAIR(0x0B01, 0x0B01)
-		PAIR(0x0B3C, 0x0B3C)
-		PAIR(0x0B3F, 0x0B3F)
-		PAIR(0x0B41, 0x0B43)
-		PAIR(0x0B4D, 0x0B4D)
-		PAIR(0x0B56, 0x0B56)
-		PAIR(0x0B82, 0x0B82)
-		PAIR(0x0BC0, 0x0BC0)
-		PAIR(0x0BCD, 0x0BCD)
-		PAIR(0x0C3E, 0x0C40)
-		PAIR(0x0C46, 0x0C48)
-		PAIR(0x0C4A, 0x0C4D)
-		PAIR(0x0C55, 0x0C56)
-		PAIR(0x0CBC, 0x0CBC)
-		PAIR(0x0CBF, 0x0CBF)
-		PAIR(0x0CC6, 0x0CC6)
-		PAIR(0x0CCC, 0x0CCD)
-		PAIR(0x0CE2, 0x0CE3)
-		PAIR(0x0D41, 0x0D43)
-		PAIR(0x0D4D, 0x0D4D)
-		PAIR(0x0DCA, 0x0DCA)
-		PAIR(0x0DD2, 0x0DD4)
-		PAIR(0x0DD6, 0x0DD6)
-		PAIR(0x0E31, 0x0E31)
-		BIG_(0x0E34, 0x0E3A)
-		BIG_(0x0E47, 0x0E4E)
-		PAIR(0x0EB1, 0x0EB1)
-		BIG_(0x0EB4, 0x0EB9)
-		PAIR(0x0EBB, 0x0EBC)
-		BIG_(0x0EC8, 0x0ECD)
-		PAIR(0x0F18, 0x0F19)
-		PAIR(0x0F35, 0x0F35)
-		PAIR(0x0F37, 0x0F37)
-		PAIR(0x0F39, 0x0F39)
-		BIG_(0x0F71, 0x0F7E)
-		BIG_(0x0F80, 0x0F84)
-		PAIR(0x0F86, 0x0F87)
-		PAIR(0x0FC6, 0x0FC6)
-		BIG_(0x0F90, 0x0F97)
-		BIG_(0x0F99, 0x0FBC)
-		PAIR(0x102D, 0x1030)
-		PAIR(0x1032, 0x1032)
-		PAIR(0x1036, 0x1037)
-		PAIR(0x1039, 0x1039)
-		PAIR(0x1058, 0x1059)
-		BIG_(0x1160, 0x11FF)
-		PAIR(0x135F, 0x135F)
-		PAIR(0x1712, 0x1714)
-		PAIR(0x1732, 0x1734)
-		PAIR(0x1752, 0x1753)
-		PAIR(0x1772, 0x1773)
-		PAIR(0x17B4, 0x17B5)
-		BIG_(0x17B7, 0x17BD)
-		PAIR(0x17C6, 0x17C6)
-		BIG_(0x17C9, 0x17D3)
-		PAIR(0x17DD, 0x17DD)
-		PAIR(0x180B, 0x180D)
-		PAIR(0x18A9, 0x18A9)
-		PAIR(0x1920, 0x1922)
-		PAIR(0x1927, 0x1928)
-		PAIR(0x1932, 0x1932)
-		PAIR(0x1939, 0x193B)
-		PAIR(0x1A17, 0x1A18)
-		PAIR(0x1B00, 0x1B03)
-		PAIR(0x1B34, 0x1B34)
-		BIG_(0x1B36, 0x1B3A)
-		PAIR(0x1B3C, 0x1B3C)
-		PAIR(0x1B42, 0x1B42)
-		BIG_(0x1B6B, 0x1B73)
-		BIG_(0x1DC0, 0x1DCA)
-		PAIR(0x1DFE, 0x1DFF)
-		BIG_(0x200B, 0x200F)
-		BIG_(0x202A, 0x202E)
-		PAIR(0x2060, 0x2063)
-		BIG_(0x206A, 0x206F)
-		BIG_(0x20D0, 0x20EF)
-		BIG_(0x302A, 0x302F)
-		PAIR(0x3099, 0x309A)
-#undef BIG_
-#undef PAIR
-	};
-	struct CHECK {
-#define BIG_(a,b) char big##a[b-a <= 3 ? -1 : 1];
-#define PAIR(a,b) char pair##a[b-a > 3 ? -1 : 1];
-		/* Copy-n-paste it here again to verify correctness */
-#undef BIG_
-#undef PAIR
-	};
-#endif
-
-	if (ucs == 0)
-		return 0;
-
-	/* Test for 8-bit control characters (00-1f, 80-9f, 7f) */
-	if ((ucs & ~0x80) < 0x20 || ucs == 0x7f)
-		return -1;
-	/* Quick abort if it is an obviously invalid char */
-	if (ucs > LAST_SUPPORTED_WCHAR)
-		return -1;
-
-	/* Optimization: no combining chars below 0x300 */
-	if (LAST_SUPPORTED_WCHAR < 0x300 || ucs < 0x300)
-		return 1;
-
-#if LAST_SUPPORTED_WCHAR >= 0x300
-	/* Binary search in table of non-spacing characters */
-	if (in_interval_table(ucs, combining, ARRAY_SIZE(combining) - 1))
-		return 0;
-	if (in_uint16_table(ucs, combining1, ARRAY_SIZE(combining1) - 1))
-		return 0;
-
-	/* Optimization: all chars below 0x1100 are not double-width */
-	if (LAST_SUPPORTED_WCHAR < 0x1100 || ucs < 0x1100)
-		return 1;
-
-# if LAST_SUPPORTED_WCHAR >= 0x1100
-	/* Invalid code points: */
-	/* High (d800..dbff) and low (dc00..dfff) surrogates (valid only in UTF16) */
-	/* Private Use Area (e000..f8ff) */
-	/* Noncharacters fdd0..fdef */
-	if ((LAST_SUPPORTED_WCHAR >= 0xd800 && ucs >= 0xd800 && ucs <= 0xf8ff)
-	 || (LAST_SUPPORTED_WCHAR >= 0xfdd0 && ucs >= 0xfdd0 && ucs <= 0xfdef)
-	) {
-		return -1;
-	}
-	/* 0xfffe and 0xffff in every plane are invalid */
-	if (LAST_SUPPORTED_WCHAR >= 0xfffe && ((ucs & 0xfffe) == 0xfffe)) {
-		return -1;
-	}
-
-#  if LAST_SUPPORTED_WCHAR >= 0x10000
-	if (ucs >= 0x10000) {
-		/* Combining chars in Supplementary Multilingual Plane 0x1xxxx */
-		static const struct interval combining0x10000[] = {
-			{ 0x0A01, 0x0A03 }, { 0x0A05, 0x0A06 }, { 0x0A0C, 0x0A0F },
-			{ 0x0A38, 0x0A3A }, { 0x0A3F, 0x0A3F }, { 0xD167, 0xD169 },
-			{ 0xD173, 0xD182 }, { 0xD185, 0xD18B }, { 0xD1AA, 0xD1AD },
-			{ 0xD242, 0xD244 }
-		};
-		/* Binary search in table of non-spacing characters in Supplementary Multilingual Plane */
-		if (in_interval_table(ucs ^ 0x10000, combining0x10000, ARRAY_SIZE(combining0x10000) - 1))
-			return 0;
-		/* Check a few non-spacing chars in Supplementary Special-purpose Plane 0xExxxx */
-		if (LAST_SUPPORTED_WCHAR >= 0xE0001
-		 && (  ucs == 0xE0001
-		    || (ucs >= 0xE0020 && ucs <= 0xE007F)
-		    || (ucs >= 0xE0100 && ucs <= 0xE01EF)
-		    )
-		) {
-			return 0;
-		}
-	}
-#  endif
-
-	/* If we arrive here, ucs is not a combining or C0/C1 control character.
-	 * Check whether it's 1 char or 2-shar wide.
-	 */
-	return 1 +
-		(  (/*ucs >= 0x1100 &&*/ ucs <= 0x115f) /* Hangul Jamo init. consonants */
-		|| ucs == 0x2329 /* left-pointing angle bracket; also CJK punct. char */
-		|| ucs == 0x232a /* right-pointing angle bracket; also CJK punct. char */
-		|| (ucs >= 0x2e80 && ucs <= 0xa4cf && ucs != 0x303f) /* CJK ... Yi */
-#  if LAST_SUPPORTED_WCHAR >= 0xac00
-		|| (ucs >= 0xac00 && ucs <= 0xd7a3) /* Hangul Syllables */
-		|| (ucs >= 0xf900 && ucs <= 0xfaff) /* CJK Compatibility Ideographs */
-		|| (ucs >= 0xfe10 && ucs <= 0xfe19) /* Vertical forms */
-		|| (ucs >= 0xfe30 && ucs <= 0xfe6f) /* CJK Compatibility Forms */
-		|| (ucs >= 0xff00 && ucs <= 0xff60) /* Fullwidth Forms */
-		|| (ucs >= 0xffe0 && ucs <= 0xffe6)
-		|| ((ucs >> 17) == (2 >> 1)) /* 20000..3ffff: Supplementary and Tertiary Ideographic Planes */
-#  endif
-		);
-# endif /* >= 0x1100 */
-#endif /* >= 0x300 */
-}
diff --git a/modutils/lsmod.c b/modutils/lsmod.c
index 50621c245..97954c71f 100644
--- a/modutils/lsmod.c
+++ b/modutils/lsmod.c
@@ -60,7 +60,7 @@ int lsmod_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 				token[3][strlen(token[3])-1] = '\0';
 			} else
 				token[3] = (char *) "";
-# if ENABLE_FEATURE_ASSUME_UNICODE
+# if ENABLE_UNICODE_SUPPORT
 			{
 				uni_stat_t uni_stat;
 				char *uni_name = unicode_conv_to_printable(&uni_stat, token[0]);
@@ -78,7 +78,7 @@ int lsmod_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 			// or comma-separated list ended by comma
 			// so trimming the trailing char is just what we need!
 			token[3][strlen(token[3])-1] = '\0';
-# if ENABLE_FEATURE_ASSUME_UNICODE
+# if ENABLE_UNICODE_SUPPORT
 			{
 				uni_stat_t uni_stat;
 				char *uni_name = unicode_conv_to_printable(&uni_stat, token[0]);
diff --git a/networking/udhcp/dumpleases.c b/networking/udhcp/dumpleases.c
index 6ebda94b6..fb6219fba 100644
--- a/networking/udhcp/dumpleases.c
+++ b/networking/udhcp/dumpleases.c
@@ -66,7 +66,7 @@ int dumpleases_main(int argc UNUSED_PARAM, char **argv)
 			fmt = ":%02x";
 		}
 		addr.s_addr = lease.lease_nip;
-#if ENABLE_FEATURE_ASSUME_UNICODE
+#if ENABLE_UNICODE_SUPPORT
 		{
 			char *uni_name = unicode_conv_to_printable_fixedwidth(NULL, lease.hostname, 19);
 			printf(" %-16s%s ", inet_ntoa(addr), uni_name);
diff --git a/scripts/defconfig b/scripts/defconfig
index 49158ceca..d13f5b1b4 100644
--- a/scripts/defconfig
+++ b/scripts/defconfig
@@ -24,7 +24,7 @@ CONFIG_FEATURE_VERBOSE_USAGE=y
 CONFIG_FEATURE_COMPRESS_USAGE=y
 CONFIG_FEATURE_INSTALLER=y
 CONFIG_LOCALE_SUPPORT=y
-CONFIG_FEATURE_ASSUME_UNICODE=y
+CONFIG_UNICODE_SUPPORT=y
 # CONFIG_FEATURE_CHECK_UNICODE_IN_ENV is not set
 CONFIG_LONG_OPTS=y
 CONFIG_FEATURE_DEVPTS=y
diff --git a/scripts/randomtest b/scripts/randomtest
index 2a30cb638..6b7db9239 100755
--- a/scripts/randomtest
+++ b/scripts/randomtest
@@ -50,7 +50,7 @@ cat .config \
 | grep -v ^CONFIG_BUILD_LIBBUSYBOX= \
 | grep -v ^CONFIG_PAM= \
 | grep -v ^CONFIG_TASKSET= \
-| grep -v ^CONFIG_FEATURE_ASSUME_UNICODE= \
+| grep -v ^CONFIG_UNICODE_SUPPORT= \
 | grep -v ^CONFIG_PIE= \
 | grep -v CONFIG_STATIC \
 | grep -v CONFIG_CROSS_COMPILER_PREFIX \
diff --git a/testsuite/cal.tests b/testsuite/cal.tests
index 36be2b4b5..30985688b 100755
--- a/testsuite/cal.tests
+++ b/testsuite/cal.tests
@@ -20,7 +20,7 @@ Su Mo Tu We Th Fr Sa
 " "" ""
 
 test x"$CONFIG_LOCALE_SUPPORT" = x"y" \
-&& test x"$CONFIG_FEATURE_ASSUME_UNICODE" = x"y" \
+&& test x"$CONFIG_UNICODE_SUPPORT" = x"y" \
 && test x"$CONFIG_LAST_SUPPORTED_WCHAR" = x"0" \
 && test x"$CONFIG_UNICODE_WIDE_WCHARS" = x"y" \
 && test x"$CONFIG_STATIC" != x"y" \
diff --git a/testsuite/ls.tests b/testsuite/ls.tests
index 169313a63..0680762fc 100755
--- a/testsuite/ls.tests
+++ b/testsuite/ls.tests
@@ -14,7 +14,7 @@ mkdir ls.testdir || exit 1
 # With Unicode provided by libc locale, I'm not sure this test can pass.
 # I suspect we might fail to skip exactly correct number of bytes
 # over broked unicode sequences.
-test x"$CONFIG_FEATURE_ASSUME_UNICODE" = x"y" \
+test x"$CONFIG_UNICODE_SUPPORT" = x"y" \
 && test x"$CONFIG_LOCALE_SUPPORT" != x"y" \
 && test x"$CONFIG_SUBST_WCHAR" = x"63" \
 && test x"$CONFIG_LAST_SUPPORTED_WCHAR" = x"767" \
@@ -133,7 +133,7 @@ test x"$CONFIG_FEATURE_ASSUME_UNICODE" = x"y" \
 ' "" ""
 
 # Currently fails on "0080_4.2.2__U-000007FF_=_e0_9f_bf" line
-test x"$CONFIG_FEATURE_ASSUME_UNICODE" = x"y" \
+test x"$CONFIG_UNICODE_SUPPORT" = x"y" \
 && test x"$CONFIG_LOCALE_SUPPORT" != x"y" \
 && test x"$CONFIG_SUBST_WCHAR" = x"63" \
 && test x"$CONFIG_LAST_SUPPORTED_WCHAR" = x"0" \