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