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diff --git a/lib/unilbrk/u8-width-linebreaks.c b/lib/unilbrk/u8-width-linebreaks.c
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+/* Line breaking of UTF-8 strings.
+ Copyright (C) 2001-2003, 2006-2008 Free Software Foundation, Inc.
+ Written by Bruno Haible <bruno@clisp.org>, 2001.
+
+ This program is free software: you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published
+ by the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+
+/* Specification. */
+#include "unilbrk.h"
+
+#include "unistr.h"
+#include "uniwidth.h"
+
+int
+u8_width_linebreaks (const uint8_t *s, size_t n,
+ int width, int start_column, int at_end_columns,
+ const char *o, const char *encoding,
+ char *p)
+{
+ const uint8_t *s_end;
+ char *last_p;
+ int last_column;
+ int piece_width;
+
+ u8_possible_linebreaks (s, n, encoding, p);
+
+ s_end = s + n;
+ last_p = NULL;
+ last_column = start_column;
+ piece_width = 0;
+ while (s < s_end)
+ {
+ ucs4_t uc;
+ int count = u8_mbtouc_unsafe (&uc, s, s_end - s);
+
+ /* Respect the override. */
+ if (o != NULL && *o != UC_BREAK_UNDEFINED)
+ *p = *o;
+
+ if (*p == UC_BREAK_POSSIBLE || *p == UC_BREAK_MANDATORY)
+ {
+ /* An atomic piece of text ends here. */
+ if (last_p != NULL && last_column + piece_width > width)
+ {
+ /* Insert a line break. */
+ *last_p = UC_BREAK_POSSIBLE;
+ last_column = 0;
+ }
+ }
+
+ if (*p == UC_BREAK_MANDATORY)
+ {
+ /* uc is a line break character. */
+ /* Start a new piece at column 0. */
+ last_p = NULL;
+ last_column = 0;
+ piece_width = 0;
+ }
+ else
+ {
+ /* uc is not a line break character. */
+ int w;
+
+ if (*p == UC_BREAK_POSSIBLE)
+ {
+ /* Start a new piece. */
+ last_p = p;
+ last_column += piece_width;
+ piece_width = 0;
+ /* No line break for the moment, may be turned into
+ UC_BREAK_POSSIBLE later, via last_p. */
+ }
+
+ *p = UC_BREAK_PROHIBITED;
+
+ w = uc_width (uc, encoding);
+ if (w >= 0) /* ignore control characters in the string */
+ piece_width += w;
+ }
+
+ s += count;
+ p += count;
+ if (o != NULL)
+ o += count;
+ }
+
+ /* The last atomic piece of text ends here. */
+ if (last_p != NULL && last_column + piece_width + at_end_columns > width)
+ {
+ /* Insert a line break. */
+ *last_p = UC_BREAK_POSSIBLE;
+ last_column = 0;
+ }
+
+ return last_column + piece_width;
+}
+
+
+#ifdef TEST
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* Read the contents of an input stream, and return it, terminated with a NUL
+ byte. */
+char *
+read_file (FILE *stream)
+{
+#define BUFSIZE 4096
+ char *buf = NULL;
+ int alloc = 0;
+ int size = 0;
+ int count;
+
+ while (! feof (stream))
+ {
+ if (size + BUFSIZE > alloc)
+ {
+ alloc = alloc + alloc / 2;
+ if (alloc < size + BUFSIZE)
+ alloc = size + BUFSIZE;
+ buf = realloc (buf, alloc);
+ if (buf == NULL)
+ {
+ fprintf (stderr, "out of memory\n");
+ exit (1);
+ }
+ }
+ count = fread (buf + size, 1, BUFSIZE, stream);
+ if (count == 0)
+ {
+ if (ferror (stream))
+ {
+ perror ("fread");
+ exit (1);
+ }
+ }
+ else
+ size += count;
+ }
+ buf = realloc (buf, size + 1);
+ if (buf == NULL)
+ {
+ fprintf (stderr, "out of memory\n");
+ exit (1);
+ }
+ buf[size] = '\0';
+ return buf;
+#undef BUFSIZE
+}
+
+int
+main (int argc, char * argv[])
+{
+ if (argc == 2)
+ {
+ /* Insert line breaks for a given width. */
+ int width = atoi (argv[1]);
+ char *input = read_file (stdin);
+ int length = strlen (input);
+ char *breaks = malloc (length);
+ int i;
+
+ u8_width_linebreaks ((uint8_t *) input, length, width, 0, 0, NULL, "UTF-8", breaks);
+
+ for (i = 0; i < length; i++)
+ {
+ switch (breaks[i])
+ {
+ case UC_BREAK_POSSIBLE:
+ putc ('\n', stdout);
+ break;
+ case UC_BREAK_MANDATORY:
+ break;
+ case UC_BREAK_PROHIBITED:
+ break;
+ default:
+ abort ();
+ }
+ putc (input[i], stdout);
+ }
+
+ free (breaks);
+
+ return 0;
+ }
+ else
+ return 1;
+}
+
+#endif /* TEST */