Merge branch 'jc/abbrev-doc'
[git] / compat / precompose_utf8.c
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
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
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
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
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
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
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 }