diff --git a/.gitignore b/.gitignore
index dc600f9b36..42294e59a1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -226,6 +226,7 @@
 /config.mak.autogen
 /config.mak.append
 /configure
+/unicode
 /tags
 /TAGS
 /cscope*
diff --git a/Makefile b/Makefile
index 08fc9ca430..07ea105837 100644
--- a/Makefile
+++ b/Makefile
@@ -729,6 +729,7 @@ LIB_H += transport.h
 LIB_H += tree-walk.h
 LIB_H += tree.h
 LIB_H += unpack-trees.h
+LIB_H += unicode_width.h
 LIB_H += url.h
 LIB_H += urlmatch.h
 LIB_H += userdiff.h
diff --git a/unicode_width.h b/unicode_width.h
new file mode 100644
index 0000000000..4db78038e4
--- /dev/null
+++ b/unicode_width.h
@@ -0,0 +1,288 @@
+static const struct interval zero_width[] = {
+{ 0x0300, 0x036F },
+{ 0x0483, 0x0489 },
+{ 0x0591, 0x05BD },
+{ 0x05BF, 0x05BF },
+{ 0x05C1, 0x05C2 },
+{ 0x05C4, 0x05C5 },
+{ 0x05C7, 0x05C7 },
+{ 0x0600, 0x0604 },
+{ 0x0610, 0x061A },
+{ 0x061C, 0x061C },
+{ 0x064B, 0x065F },
+{ 0x0670, 0x0670 },
+{ 0x06D6, 0x06DD },
+{ 0x06DF, 0x06E4 },
+{ 0x06E7, 0x06E8 },
+{ 0x06EA, 0x06ED },
+{ 0x070F, 0x070F },
+{ 0x0711, 0x0711 },
+{ 0x0730, 0x074A },
+{ 0x07A6, 0x07B0 },
+{ 0x07EB, 0x07F3 },
+{ 0x0816, 0x0819 },
+{ 0x081B, 0x0823 },
+{ 0x0825, 0x0827 },
+{ 0x0829, 0x082D },
+{ 0x0859, 0x085B },
+{ 0x08E4, 0x08FE },
+{ 0x0900, 0x0902 },
+{ 0x093A, 0x093A },
+{ 0x093C, 0x093C },
+{ 0x0941, 0x0948 },
+{ 0x094D, 0x094D },
+{ 0x0951, 0x0957 },
+{ 0x0962, 0x0963 },
+{ 0x0981, 0x0981 },
+{ 0x09BC, 0x09BC },
+{ 0x09C1, 0x09C4 },
+{ 0x09CD, 0x09CD },
+{ 0x09E2, 0x09E3 },
+{ 0x0A01, 0x0A02 },
+{ 0x0A3C, 0x0A3C },
+{ 0x0A41, 0x0A42 },
+{ 0x0A47, 0x0A48 },
+{ 0x0A4B, 0x0A4D },
+{ 0x0A51, 0x0A51 },
+{ 0x0A70, 0x0A71 },
+{ 0x0A75, 0x0A75 },
+{ 0x0A81, 0x0A82 },
+{ 0x0ABC, 0x0ABC },
+{ 0x0AC1, 0x0AC5 },
+{ 0x0AC7, 0x0AC8 },
+{ 0x0ACD, 0x0ACD },
+{ 0x0AE2, 0x0AE3 },
+{ 0x0B01, 0x0B01 },
+{ 0x0B3C, 0x0B3C },
+{ 0x0B3F, 0x0B3F },
+{ 0x0B41, 0x0B44 },
+{ 0x0B4D, 0x0B4D },
+{ 0x0B56, 0x0B56 },
+{ 0x0B62, 0x0B63 },
+{ 0x0B82, 0x0B82 },
+{ 0x0BC0, 0x0BC0 },
+{ 0x0BCD, 0x0BCD },
+{ 0x0C3E, 0x0C40 },
+{ 0x0C46, 0x0C48 },
+{ 0x0C4A, 0x0C4D },
+{ 0x0C55, 0x0C56 },
+{ 0x0C62, 0x0C63 },
+{ 0x0CBC, 0x0CBC },
+{ 0x0CBF, 0x0CBF },
+{ 0x0CC6, 0x0CC6 },
+{ 0x0CCC, 0x0CCD },
+{ 0x0CE2, 0x0CE3 },
+{ 0x0D41, 0x0D44 },
+{ 0x0D4D, 0x0D4D },
+{ 0x0D62, 0x0D63 },
+{ 0x0DCA, 0x0DCA },
+{ 0x0DD2, 0x0DD4 },
+{ 0x0DD6, 0x0DD6 },
+{ 0x0E31, 0x0E31 },
+{ 0x0E34, 0x0E3A },
+{ 0x0E47, 0x0E4E },
+{ 0x0EB1, 0x0EB1 },
+{ 0x0EB4, 0x0EB9 },
+{ 0x0EBB, 0x0EBC },
+{ 0x0EC8, 0x0ECD },
+{ 0x0F18, 0x0F19 },
+{ 0x0F35, 0x0F35 },
+{ 0x0F37, 0x0F37 },
+{ 0x0F39, 0x0F39 },
+{ 0x0F71, 0x0F7E },
+{ 0x0F80, 0x0F84 },
+{ 0x0F86, 0x0F87 },
+{ 0x0F8D, 0x0F97 },
+{ 0x0F99, 0x0FBC },
+{ 0x0FC6, 0x0FC6 },
+{ 0x102D, 0x1030 },
+{ 0x1032, 0x1037 },
+{ 0x1039, 0x103A },
+{ 0x103D, 0x103E },
+{ 0x1058, 0x1059 },
+{ 0x105E, 0x1060 },
+{ 0x1071, 0x1074 },
+{ 0x1082, 0x1082 },
+{ 0x1085, 0x1086 },
+{ 0x108D, 0x108D },
+{ 0x109D, 0x109D },
+{ 0x1160, 0x11FF },
+{ 0x135D, 0x135F },
+{ 0x1712, 0x1714 },
+{ 0x1732, 0x1734 },
+{ 0x1752, 0x1753 },
+{ 0x1772, 0x1773 },
+{ 0x17B4, 0x17B5 },
+{ 0x17B7, 0x17BD },
+{ 0x17C6, 0x17C6 },
+{ 0x17C9, 0x17D3 },
+{ 0x17DD, 0x17DD },
+{ 0x180B, 0x180E },
+{ 0x18A9, 0x18A9 },
+{ 0x1920, 0x1922 },
+{ 0x1927, 0x1928 },
+{ 0x1932, 0x1932 },
+{ 0x1939, 0x193B },
+{ 0x1A17, 0x1A18 },
+{ 0x1A1B, 0x1A1B },
+{ 0x1A56, 0x1A56 },
+{ 0x1A58, 0x1A5E },
+{ 0x1A60, 0x1A60 },
+{ 0x1A62, 0x1A62 },
+{ 0x1A65, 0x1A6C },
+{ 0x1A73, 0x1A7C },
+{ 0x1A7F, 0x1A7F },
+{ 0x1B00, 0x1B03 },
+{ 0x1B34, 0x1B34 },
+{ 0x1B36, 0x1B3A },
+{ 0x1B3C, 0x1B3C },
+{ 0x1B42, 0x1B42 },
+{ 0x1B6B, 0x1B73 },
+{ 0x1B80, 0x1B81 },
+{ 0x1BA2, 0x1BA5 },
+{ 0x1BA8, 0x1BA9 },
+{ 0x1BAB, 0x1BAB },
+{ 0x1BE6, 0x1BE6 },
+{ 0x1BE8, 0x1BE9 },
+{ 0x1BED, 0x1BED },
+{ 0x1BEF, 0x1BF1 },
+{ 0x1C2C, 0x1C33 },
+{ 0x1C36, 0x1C37 },
+{ 0x1CD0, 0x1CD2 },
+{ 0x1CD4, 0x1CE0 },
+{ 0x1CE2, 0x1CE8 },
+{ 0x1CED, 0x1CED },
+{ 0x1CF4, 0x1CF4 },
+{ 0x1DC0, 0x1DE6 },
+{ 0x1DFC, 0x1DFF },
+{ 0x200B, 0x200F },
+{ 0x202A, 0x202E },
+{ 0x2060, 0x2064 },
+{ 0x2066, 0x206F },
+{ 0x20D0, 0x20F0 },
+{ 0x2CEF, 0x2CF1 },
+{ 0x2D7F, 0x2D7F },
+{ 0x2DE0, 0x2DFF },
+{ 0x302A, 0x302D },
+{ 0x3099, 0x309A },
+{ 0xA66F, 0xA672 },
+{ 0xA674, 0xA67D },
+{ 0xA69F, 0xA69F },
+{ 0xA6F0, 0xA6F1 },
+{ 0xA802, 0xA802 },
+{ 0xA806, 0xA806 },
+{ 0xA80B, 0xA80B },
+{ 0xA825, 0xA826 },
+{ 0xA8C4, 0xA8C4 },
+{ 0xA8E0, 0xA8F1 },
+{ 0xA926, 0xA92D },
+{ 0xA947, 0xA951 },
+{ 0xA980, 0xA982 },
+{ 0xA9B3, 0xA9B3 },
+{ 0xA9B6, 0xA9B9 },
+{ 0xA9BC, 0xA9BC },
+{ 0xAA29, 0xAA2E },
+{ 0xAA31, 0xAA32 },
+{ 0xAA35, 0xAA36 },
+{ 0xAA43, 0xAA43 },
+{ 0xAA4C, 0xAA4C },
+{ 0xAAB0, 0xAAB0 },
+{ 0xAAB2, 0xAAB4 },
+{ 0xAAB7, 0xAAB8 },
+{ 0xAABE, 0xAABF },
+{ 0xAAC1, 0xAAC1 },
+{ 0xAAEC, 0xAAED },
+{ 0xAAF6, 0xAAF6 },
+{ 0xABE5, 0xABE5 },
+{ 0xABE8, 0xABE8 },
+{ 0xABED, 0xABED },
+{ 0xFB1E, 0xFB1E },
+{ 0xFE00, 0xFE0F },
+{ 0xFE20, 0xFE26 },
+{ 0xFEFF, 0xFEFF },
+{ 0xFFF9, 0xFFFB },
+{ 0x101FD, 0x101FD },
+{ 0x10A01, 0x10A03 },
+{ 0x10A05, 0x10A06 },
+{ 0x10A0C, 0x10A0F },
+{ 0x10A38, 0x10A3A },
+{ 0x10A3F, 0x10A3F },
+{ 0x11001, 0x11001 },
+{ 0x11038, 0x11046 },
+{ 0x11080, 0x11081 },
+{ 0x110B3, 0x110B6 },
+{ 0x110B9, 0x110BA },
+{ 0x110BD, 0x110BD },
+{ 0x11100, 0x11102 },
+{ 0x11127, 0x1112B },
+{ 0x1112D, 0x11134 },
+{ 0x11180, 0x11181 },
+{ 0x111B6, 0x111BE },
+{ 0x116AB, 0x116AB },
+{ 0x116AD, 0x116AD },
+{ 0x116B0, 0x116B5 },
+{ 0x116B7, 0x116B7 },
+{ 0x16F8F, 0x16F92 },
+{ 0x1D167, 0x1D169 },
+{ 0x1D173, 0x1D182 },
+{ 0x1D185, 0x1D18B },
+{ 0x1D1AA, 0x1D1AD },
+{ 0x1D242, 0x1D244 },
+{ 0xE0001, 0xE0001 },
+{ 0xE0020, 0xE007F },
+{ 0xE0100, 0xE01EF }
+};
+static const struct interval double_width[] = {
+{ /* plane */ 0x0, 0x1C },
+{ /* plane */ 0x1C, 0x21 },
+{ /* plane */ 0x21, 0x22 },
+{ /* plane */ 0x22, 0x23 },
+{ /* plane */ 0x0, 0x0 },
+{ /* plane */ 0x0, 0x0 },
+{ /* plane */ 0x0, 0x0 },
+{ /* plane */ 0x0, 0x0 },
+{ /* plane */ 0x0, 0x0 },
+{ /* plane */ 0x0, 0x0 },
+{ /* plane */ 0x0, 0x0 },
+{ /* plane */ 0x0, 0x0 },
+{ /* plane */ 0x0, 0x0 },
+{ /* plane */ 0x0, 0x0 },
+{ /* plane */ 0x0, 0x0 },
+{ /* plane */ 0x0, 0x0 },
+{ /* plane */ 0x0, 0x0 },
+{ 0x1100, 0x115F },
+{ 0x2329, 0x232A },
+{ 0x2E80, 0x2E99 },
+{ 0x2E9B, 0x2EF3 },
+{ 0x2F00, 0x2FD5 },
+{ 0x2FF0, 0x2FFB },
+{ 0x3000, 0x303E },
+{ 0x3041, 0x3096 },
+{ 0x3099, 0x30FF },
+{ 0x3105, 0x312D },
+{ 0x3131, 0x318E },
+{ 0x3190, 0x31BA },
+{ 0x31C0, 0x31E3 },
+{ 0x31F0, 0x321E },
+{ 0x3220, 0x3247 },
+{ 0x3250, 0x32FE },
+{ 0x3300, 0x4DBF },
+{ 0x4E00, 0xA48C },
+{ 0xA490, 0xA4C6 },
+{ 0xA960, 0xA97C },
+{ 0xAC00, 0xD7A3 },
+{ 0xF900, 0xFAFF },
+{ 0xFE10, 0xFE19 },
+{ 0xFE30, 0xFE52 },
+{ 0xFE54, 0xFE66 },
+{ 0xFE68, 0xFE6B },
+{ 0xFF01, 0xFF60 },
+{ 0xFFE0, 0xFFE6 },
+{ 0x1B000, 0x1B001 },
+{ 0x1F200, 0x1F202 },
+{ 0x1F210, 0x1F23A },
+{ 0x1F240, 0x1F248 },
+{ 0x1F250, 0x1F251 },
+{ 0x20000, 0x2FFFD },
+{ 0x30000, 0x3FFFD }
+};
diff --git a/update_unicode.sh b/update_unicode.sh
new file mode 100755
index 0000000000..000b937e68
--- /dev/null
+++ b/update_unicode.sh
@@ -0,0 +1,37 @@
+#!/bin/sh
+#See http://www.unicode.org/reports/tr44/
+#
+#Me Enclosing_Mark  an enclosing combining mark
+#Mn Nonspacing_Mark a nonspacing combining mark (zero advance width)
+#Cf Format          a format control character
+#
+UNICODEWIDTH_H=../unicode_width.h
+if ! test -d unicode; then
+	mkdir unicode
+fi &&
+( cd unicode &&
+	if ! test -f UnicodeData.txt; then
+		wget http://www.unicode.org/Public/UCD/latest/ucd/UnicodeData.txt
+	fi &&
+	if ! test -f EastAsianWidth.txt; then
+		wget http://www.unicode.org/Public/UCD/latest/ucd/EastAsianWidth.txt
+	fi &&
+	if ! test -d uniset; then
+		git clone https://github.com/depp/uniset.git
+	fi &&
+	(
+		cd uniset &&
+		if ! test -x uniset; then
+			autoreconf -i &&
+			./configure --enable-warnings=-Werror CFLAGS='-O0 -ggdb'
+		fi &&
+		make
+	) &&
+	echo "static const struct interval zero_width[] = {" >$UNICODEWIDTH_H &&
+	UNICODE_DIR=. ./uniset/uniset --32 cat:Me,Mn,Cf + U+1160..U+11FF - U+00AD |
+	grep -v plane >>$UNICODEWIDTH_H &&
+	echo "};" >>$UNICODEWIDTH_H &&
+	echo "static const struct interval double_width[] = {" >>$UNICODEWIDTH_H &&
+	UNICODE_DIR=. ./uniset/uniset --32 eaw:F,W >>$UNICODEWIDTH_H &&
+	echo "};" >>$UNICODEWIDTH_H
+)
diff --git a/utf8.c b/utf8.c
index 77c28d492c..b30790d043 100644
--- a/utf8.c
+++ b/utf8.c
@@ -80,52 +80,8 @@ static int git_wcwidth(ucs_char_t ch)
 {
 	/*
 	 * 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[] = {
-		{ 0x0300, 0x036F }, { 0x0483, 0x0489 }, { 0x0591, 0x05BD },
-		{ 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 }, { 0x05C4, 0x05C5 },
-		{ 0x05C7, 0x05C7 }, { 0x0600, 0x0604 }, { 0x0610, 0x061A },
-		{ 0x064B, 0x065F }, { 0x0670, 0x0670 }, { 0x06D6, 0x06E4 },
-		{ 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x070F, 0x070F },
-		{ 0x0711, 0x0711 }, { 0x0730, 0x074A }, { 0x07A6, 0x07B0 },
-		{ 0x0901, 0x0902 }, { 0x093C, 0x093C }, { 0x0941, 0x0948 },
-		{ 0x094D, 0x094D }, { 0x0951, 0x0954 }, { 0x0962, 0x0963 },
-		{ 0x0981, 0x0981 }, { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 },
-		{ 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 },
-		{ 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 },
-		{ 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 },
-		{ 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 },
-		{ 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 },
-		{ 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 },
-		{ 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 },
-		{ 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 },
-		{ 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 },
-		{ 0x0CBC, 0x0CBC }, { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 },
-		{ 0x0CCC, 0x0CCD }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D },
-		{ 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 },
-		{ 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E },
-		{ 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC },
-		{ 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 },
-		{ 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E },
-		{ 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 },
-		{ 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 },
-		{ 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 },
-		{ 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x1712, 0x1714 },
-		{ 0x1732, 0x1734 }, { 0x1752, 0x1753 }, { 0x1772, 0x1773 },
-		{ 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, { 0x17C6, 0x17C6 },
-		{ 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, { 0x180B, 0x180D },
-		{ 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, { 0x1927, 0x1928 },
-		{ 0x1932, 0x1932 }, { 0x1939, 0x193B }, { 0x200B, 0x200F },
-		{ 0x202A, 0x202E }, { 0x2060, 0x2063 }, { 0x206A, 0x206F },
-		{ 0x20D0, 0x20EA }, { 0x302A, 0x302F }, { 0x3099, 0x309A },
-		{ 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 },
-		{ 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 },
-		{ 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B },
-		{ 0x1D1AA, 0x1D1AD }, { 0xE0001, 0xE0001 },
-		{ 0xE0020, 0xE007F }, { 0xE0100, 0xE01EF }
-	};
+#include "unicode_width.h"
 
 	/* test for 8-bit control characters */
 	if (ch == 0)
@@ -134,34 +90,16 @@ static int git_wcwidth(ucs_char_t ch)
 		return -1;
 
 	/* binary search in table of non-spacing characters */
-	if (bisearch(ch, combining, sizeof(combining)
+	if (bisearch(ch, zero_width, sizeof(zero_width)
 				/ sizeof(struct interval) - 1))
 		return 0;
 
-	/*
-	 * If we arrive here, ch is neither a combining nor a C0/C1
-	 * control character.
-	 */
+	/* binary search in table of double width characters */
+	if (bisearch(ch, double_width, sizeof(double_width)
+				/ sizeof(struct interval) - 1))
+		return 2;
 
-	return 1 +
-		(ch >= 0x1100 &&
-                    /* Hangul Jamo init. consonants */
-		 (ch <= 0x115f ||
-		  ch == 0x2329 || ch == 0x232a ||
-                  /* CJK ... Yi */
-		  (ch >= 0x2e80 && ch <= 0xa4cf &&
-		   ch != 0x303f) ||
-		  /* Hangul Syllables */
-		  (ch >= 0xac00 && ch <= 0xd7a3) ||
-		  /* CJK Compatibility Ideographs */
-		  (ch >= 0xf900 && ch <= 0xfaff) ||
-		  /* CJK Compatibility Forms */
-		  (ch >= 0xfe30 && ch <= 0xfe6f) ||
-		  /* Fullwidth Forms */
-		  (ch >= 0xff00 && ch <= 0xff60) ||
-		  (ch >= 0xffe0 && ch <= 0xffe6) ||
-		  (ch >= 0x20000 && ch <= 0x2fffd) ||
-		  (ch >= 0x30000 && ch <= 0x3fffd)));
+	return 1;
 }
 
 /*