aboutsummaryrefslogtreecommitdiffstats
path: root/src/tag/TagString.cxx
blob: 0c3868eb51c4170b2f1513cd38161a46acdc03d6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
/*
 * Copyright (C) 2003-2014 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"
#include "TagString.hxx"
#include "util/Alloc.hxx"

#ifdef HAVE_GLIB
#include <glib.h>
#endif

#include <assert.h>
#include <string.h>
#include <stdlib.h>

#ifdef HAVE_GLIB

/**
 * Replace invalid sequences with the question mark.
 */
static char *
patch_utf8(const char *src, size_t length, const gchar *end)
{
	/* duplicate the string, and replace invalid bytes in that
	   buffer */
	char *dest = xstrdup(src);

	do {
		dest[end - src] = '?';
	} while (!g_utf8_validate(end + 1, (src + length) - (end + 1), &end));

	return dest;
}

static char *
fix_utf8(const char *str, size_t length)
{
	const gchar *end;
	char *temp;
	gsize written;

	assert(str != nullptr);

	/* check if the string is already valid UTF-8 */
	if (g_utf8_validate(str, length, &end))
		return nullptr;

	/* no, it's not - try to import it from ISO-Latin-1 */
	temp = g_convert(str, length, "utf-8", "iso-8859-1",
			 nullptr, &written, nullptr);
	if (temp != nullptr) {
		/* success! */
		char *p = xstrdup(temp);
		g_free(temp);
		return p;
	}

	/* no, still broken - there's no medication, just patch
	   invalid sequences */
	return patch_utf8(str, length, end);
}

#endif

static bool
char_is_non_printable(unsigned char ch)
{
	return ch < 0x20;
}

static const char *
find_non_printable(const char *p, size_t length)
{
	for (size_t i = 0; i < length; ++i)
		if (char_is_non_printable(p[i]))
			return p + i;

	return nullptr;
}

/**
 * Clears all non-printable characters, convert them to space.
 * Returns nullptr if nothing needs to be cleared.
 */
static char *
clear_non_printable(const char *p, size_t length)
{
	const char *first = find_non_printable(p, length);
	char *dest;

	if (first == nullptr)
		return nullptr;

	dest = xstrndup(p, length);

	for (size_t i = first - p; i < length; ++i)
		if (char_is_non_printable(dest[i]))
			dest[i] = ' ';

	return dest;
}

char *
FixTagString(const char *p, size_t length)
{
#ifdef HAVE_GLIB
	// TODO: implement without GLib

	char *utf8 = fix_utf8(p, length);
	if (utf8 != nullptr) {
		p = utf8;
		length = strlen(p);
	}
#endif

	char *cleared = clear_non_printable(p, length);
#ifdef HAVE_GLIB
	if (cleared == nullptr)
		cleared = utf8;
	else
		free(utf8);
#endif

	return cleared;
}