1 /*
2  * Converts filenames from decomposed unicode into precomposed unicode.
3  * Used on MacOS X.
4  */
5 
6 #define PRECOMPOSE_UNICODE_C
7 
8 #include "cache.h"
9 #include "config.h"
10 #include "utf8.h"
11 #include "precompose_utf8.h"
12 
13 typedef char *iconv_ibp;
14 static const char *repo_encoding = "UTF-8";
15 static const char *path_encoding = "UTF-8-MAC";
16 
has_non_ascii(const char * s,size_t maxlen,size_t * strlen_c)17 static size_t has_non_ascii(const char *s, size_t maxlen, size_t *strlen_c)
18 {
19 	const uint8_t *ptr = (const uint8_t *)s;
20 	size_t strlen_chars = 0;
21 	size_t ret = 0;
22 
23 	if (!ptr || !*ptr)
24 		return 0;
25 
26 	while (*ptr && maxlen) {
27 		if (*ptr & 0x80)
28 			ret++;
29 		strlen_chars++;
30 		ptr++;
31 		maxlen--;
32 	}
33 	if (strlen_c)
34 		*strlen_c = strlen_chars;
35 
36 	return ret;
37 }
38 
39 
probe_utf8_pathname_composition(void)40 void probe_utf8_pathname_composition(void)
41 {
42 	struct strbuf path = STRBUF_INIT;
43 	static const char *auml_nfc = "\xc3\xa4";
44 	static const char *auml_nfd = "\x61\xcc\x88";
45 	int output_fd;
46 	if (precomposed_unicode != -1)
47 		return; /* We found it defined in the global config, respect it */
48 	git_path_buf(&path, "%s", auml_nfc);
49 	output_fd = open(path.buf, O_CREAT|O_EXCL|O_RDWR, 0600);
50 	if (output_fd >= 0) {
51 		close(output_fd);
52 		git_path_buf(&path, "%s", auml_nfd);
53 		precomposed_unicode = access(path.buf, R_OK) ? 0 : 1;
54 		git_config_set("core.precomposeunicode",
55 			       precomposed_unicode ? "true" : "false");
56 		git_path_buf(&path, "%s", auml_nfc);
57 		if (unlink(path.buf))
58 			die_errno(_("failed to unlink '%s'"), path.buf);
59 	}
60 	strbuf_release(&path);
61 }
62 
63 
precompose_argv(int argc,const char ** argv)64 void precompose_argv(int argc, const char **argv)
65 {
66 	int i = 0;
67 	const char *oldarg;
68 	char *newarg;
69 	iconv_t ic_precompose;
70 
71 	if (precomposed_unicode != 1)
72 		return;
73 
74 	ic_precompose = iconv_open(repo_encoding, path_encoding);
75 	if (ic_precompose == (iconv_t) -1)
76 		return;
77 
78 	while (i < argc) {
79 		size_t namelen;
80 		oldarg = argv[i];
81 		if (has_non_ascii(oldarg, (size_t)-1, &namelen)) {
82 			newarg = reencode_string_iconv(oldarg, namelen, ic_precompose, 0, NULL);
83 			if (newarg)
84 				argv[i] = newarg;
85 		}
86 		i++;
87 	}
88 	iconv_close(ic_precompose);
89 }
90 
91 
precompose_utf8_opendir(const char * dirname)92 PREC_DIR *precompose_utf8_opendir(const char *dirname)
93 {
94 	PREC_DIR *prec_dir = xmalloc(sizeof(PREC_DIR));
95 	prec_dir->dirent_nfc = xmalloc(sizeof(dirent_prec_psx));
96 	prec_dir->dirent_nfc->max_name_len = sizeof(prec_dir->dirent_nfc->d_name);
97 
98 	prec_dir->dirp = opendir(dirname);
99 	if (!prec_dir->dirp) {
100 		free(prec_dir->dirent_nfc);
101 		free(prec_dir);
102 		return NULL;
103 	} else {
104 		int ret_errno = errno;
105 		prec_dir->ic_precompose = iconv_open(repo_encoding, path_encoding);
106 		/* if iconv_open() fails, die() in readdir() if needed */
107 		errno = ret_errno;
108 	}
109 
110 	return prec_dir;
111 }
112 
precompose_utf8_readdir(PREC_DIR * prec_dir)113 struct dirent_prec_psx *precompose_utf8_readdir(PREC_DIR *prec_dir)
114 {
115 	struct dirent *res;
116 	res = readdir(prec_dir->dirp);
117 	if (res) {
118 		size_t namelenz = strlen(res->d_name) + 1; /* \0 */
119 		size_t new_maxlen = namelenz;
120 
121 		int ret_errno = errno;
122 
123 		if (new_maxlen > prec_dir->dirent_nfc->max_name_len) {
124 			size_t new_len = sizeof(dirent_prec_psx) + new_maxlen -
125 				sizeof(prec_dir->dirent_nfc->d_name);
126 
127 			prec_dir->dirent_nfc = xrealloc(prec_dir->dirent_nfc, new_len);
128 			prec_dir->dirent_nfc->max_name_len = new_maxlen;
129 		}
130 
131 		prec_dir->dirent_nfc->d_ino  = res->d_ino;
132 		prec_dir->dirent_nfc->d_type = res->d_type;
133 
134 		if ((precomposed_unicode == 1) && has_non_ascii(res->d_name, (size_t)-1, NULL)) {
135 			if (prec_dir->ic_precompose == (iconv_t)-1) {
136 				die("iconv_open(%s,%s) failed, but needed:\n"
137 						"    precomposed unicode is not supported.\n"
138 						"    If you want to use decomposed unicode, run\n"
139 						"    \"git config core.precomposeunicode false\"\n",
140 						repo_encoding, path_encoding);
141 			} else {
142 				iconv_ibp	cp = (iconv_ibp)res->d_name;
143 				size_t inleft = namelenz;
144 				char *outpos = &prec_dir->dirent_nfc->d_name[0];
145 				size_t outsz = prec_dir->dirent_nfc->max_name_len;
146 				errno = 0;
147 				iconv(prec_dir->ic_precompose, &cp, &inleft, &outpos, &outsz);
148 				if (errno || inleft) {
149 					/*
150 					 * iconv() failed and errno could be E2BIG, EILSEQ, EINVAL, EBADF
151 					 * MacOS X avoids illegal byte sequences.
152 					 * If they occur on a mounted drive (e.g. NFS) it is not worth to
153 					 * die() for that, but rather let the user see the original name
154 					*/
155 					namelenz = 0; /* trigger strlcpy */
156 				}
157 			}
158 		} else
159 			namelenz = 0;
160 
161 		if (!namelenz)
162 			strlcpy(prec_dir->dirent_nfc->d_name, res->d_name,
163 							prec_dir->dirent_nfc->max_name_len);
164 
165 		errno = ret_errno;
166 		return prec_dir->dirent_nfc;
167 	}
168 	return NULL;
169 }
170 
171 
precompose_utf8_closedir(PREC_DIR * prec_dir)172 int precompose_utf8_closedir(PREC_DIR *prec_dir)
173 {
174 	int ret_value;
175 	int ret_errno;
176 	ret_value = closedir(prec_dir->dirp);
177 	ret_errno = errno;
178 	if (prec_dir->ic_precompose != (iconv_t)-1)
179 		iconv_close(prec_dir->ic_precompose);
180 	free(prec_dir->dirent_nfc);
181 	free(prec_dir);
182 	errno = ret_errno;
183 	return ret_value;
184 }
185