libbb: better unicode width support. Hopefully fixes bug 839.

Also opens up a possibility to make other unicode stuff smaller
and more correct later. but:

function                                             old     new   delta
static.combining                                       -     516    +516
bb_wcwidth                                             -     328    +328
unicode_cut_nchars                                     -     141    +141
mbstowc_internal                                       -      93     +93
in_table                                               -      78     +78
cal_main                                             899     961     +62
static.combining0x10000                                -      40     +40
unicode_strlen                                         -      31     +31
bb_mbstrlen                                           31       -     -31
bb_mbstowcs                                          173     102     -71
------------------------------------------------------------------------------
(add/remove: 7/1 grow/shrink: 1/1 up/down: 1289/-102)        Total: 1187 bytes

Uses code of Markus Kuhn, which is in public domain:
http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
"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."

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 22 insertions, 6 deletions

diff --git a/coreutils/cal.c b/coreutils/cal.c
index e6f9af9..5ecb913 100644
--- a/coreutils/cal.c
+++ b/coreutils/cal.c
@@ -16,8 +16,8 @@
  *
  * Major size reduction... over 50% (>1.5k) on i386.
  */
-
 #include "libbb.h"
+#include "unicode.h"
 
 /* We often use "unsigned" intead of "int", it's easier to div on most CPUs */
 
@@ -83,9 +83,16 @@ int cal_main(int argc UNUSED_PARAM, char **argv)
 	time_t now;
 	unsigned month, year, flags, i;
 	char *month_names[12];
-	char day_headings[28];	/* 28 for julian, 21 for nonjulian */
+	/* normal heading: */
+	/* "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 buf[40];
 
+	init_unicode();
+
 	flags = getopt32(argv, "jy");
 	/* This sets julian = flags & 1: */
 	option_mask32 &= 1;
@@ -122,15 +129,24 @@ int cal_main(int argc UNUSED_PARAM, char **argv)
 
 		if (i < 7) {
 			zero_tm.tm_wday = i;
-//FIXME: unicode
-//Bug 839:
-//testcase with doublewidth Japanese chars: "LANG=zh_TW.utf8 cal"
-//perhaps use wc[s]width() to probe terminal width
 			/* abbreviated weekday name according to locale */
 			strftime(buf, sizeof(buf), "%a", &zero_tm);
+#if ENABLE_FEATURE_ASSUME_UNICODE
+			if (julian)
+				*hp++ = ' ';
+			{
+				char *two_wchars = unicode_cut_nchars(2, buf);
+				strcpy(hp, two_wchars);
+				free(two_wchars);
+			}
+			hp += strlen(hp);
+			*hp++ = ' ';
+#else
 			strncpy(day_headings + i * (3+julian) + julian, buf, 2);
+#endif
 		}
 	} while (++i < 12);
+	IF_FEATURE_ASSUME_UNICODE(hp[-1] = '\0';)
 
 	if (month) {
 		unsigned row, len, days[MAXDAYS];