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 #define USE_THE_REPOSITORY_VARIABLE
   8
   9 #include "git-compat-util.h"
  10 #include "config.h"
  11 #include "environment.h"
  12 #include "gettext.h"
  13 #include "path.h"
  14 #include "strbuf.h"
  15 #include "utf8.h"
  16 #include "precompose_utf8.h"
  17
  18 typedef char *iconv_ibp;
  19 static const char *repo_encoding = "UTF-8";
  20 static const char *path_encoding = "UTF-8-MAC";
  21
  22 static size_t has_non_ascii(const char *s, size_t maxlen, size_t *strlen_c)
  23 {
  24         const uint8_t *ptr = (const uint8_t *)s;
  25         size_t strlen_chars = 0;
  26         size_t ret = 0;
  27
  28         if (!ptr || !*ptr)
  29                 return 0;
  30
  31         while (*ptr && maxlen) {
  32                 if (*ptr & 0x80)
  33                         ret++;
  34                 strlen_chars++;
  35                 ptr++;
  36                 maxlen--;
  37         }
  38         if (strlen_c)
  39                 *strlen_c = strlen_chars;
  40
  41         return ret;
  42 }
  43
  44
  45 void probe_utf8_pathname_composition(void)
  46 {
  47         struct strbuf path = STRBUF_INIT;
  48         static const char *auml_nfc = "\xc3\xa4";
  49         static const char *auml_nfd = "\x61\xcc\x88";
  50         int output_fd;
  51         if (precomposed_unicode != -1)
  52                 return; /* We found it defined in the global config, respect it */
  53         git_path_buf(&path, "%s", auml_nfc);
  54         output_fd = open(path.buf, O_CREAT|O_EXCL|O_RDWR, 0600);
  55         if (output_fd >= 0) {
  56                 close(output_fd);
  57                 git_path_buf(&path, "%s", auml_nfd);
  58                 precomposed_unicode = access(path.buf, R_OK) ? 0 : 1;
  59                 git_config_set("core.precomposeunicode",
  60                                precomposed_unicode ? "true" : "false");
  61                 git_path_buf(&path, "%s", auml_nfc);
  62                 if (unlink(path.buf))
  63                         die_errno(_("failed to unlink '%s'"), path.buf);
  64         }
  65         strbuf_release(&path);
  66 }
  67
  68 const char *precompose_string_if_needed(const char *in)
  69 {
  70         size_t inlen;
  71         size_t outlen;
  72         if (!in)
  73                 return NULL;
  74         if (has_non_ascii(in, (size_t)-1, &inlen)) {
  75                 iconv_t ic_prec;
  76                 char *out;
  77                 if (precomposed_unicode < 0)
  78                         git_config_get_bool("core.precomposeunicode", &precomposed_unicode);
  79                 if (precomposed_unicode != 1)
  80                         return in;
  81                 ic_prec = iconv_open(repo_encoding, path_encoding);
  82                 if (ic_prec == (iconv_t) -1)
  83                         return in;
  84
  85                 out = reencode_string_iconv(in, inlen, ic_prec, 0, &outlen);
  86                 if (out) {
  87                         if (outlen == inlen && !memcmp(in, out, outlen))
  88                                 free(out); /* no need to return indentical */
  89                         else
  90                                 in = out;
  91                 }
  92                 iconv_close(ic_prec);
  93
  94         }
  95         return in;
  96 }
  97
  98 const char *precompose_argv_prefix(int argc, const char **argv, const char *prefix)
  99 {
 100         int i = 0;
 101
 102         while (i < argc) {
 103                 argv[i] = precompose_string_if_needed(argv[i]);
 104                 i++;
 105         }
 106         return precompose_string_if_needed(prefix);
 107 }
 108
 109
 110 PREC_DIR *precompose_utf8_opendir(const char *dirname)
 111 {
 112         PREC_DIR *prec_dir = xmalloc(sizeof(PREC_DIR));
 113         prec_dir->dirent_nfc = xmalloc(sizeof(dirent_prec_psx));
 114         prec_dir->dirent_nfc->max_name_len = sizeof(prec_dir->dirent_nfc->d_name);
 115
 116         prec_dir->dirp = opendir(dirname);
 117         if (!prec_dir->dirp) {
 118                 free(prec_dir->dirent_nfc);
 119                 free(prec_dir);
 120                 return NULL;
 121         } else {
 122                 int ret_errno = errno;
 123                 prec_dir->ic_precompose = iconv_open(repo_encoding, path_encoding);
 124                 /* if iconv_open() fails, die() in readdir() if needed */
 125                 errno = ret_errno;
 126         }
 127
 128         return prec_dir;
 129 }
 130
 131 struct dirent_prec_psx *precompose_utf8_readdir(PREC_DIR *prec_dir)
 132 {
 133         struct dirent *res;
 134         res = readdir(prec_dir->dirp);
 135         if (res) {
 136                 size_t namelenz = strlen(res->d_name) + 1; /* \0 */
 137                 size_t new_maxlen = namelenz;
 138
 139                 int ret_errno = errno;
 140
 141                 if (new_maxlen > prec_dir->dirent_nfc->max_name_len) {
 142                         size_t new_len = sizeof(dirent_prec_psx) + new_maxlen -
 143                                 sizeof(prec_dir->dirent_nfc->d_name);
 144
 145                         prec_dir->dirent_nfc = xrealloc(prec_dir->dirent_nfc, new_len);
 146                         prec_dir->dirent_nfc->max_name_len = new_maxlen;
 147                 }
 148
 149                 prec_dir->dirent_nfc->d_ino  = res->d_ino;
 150                 prec_dir->dirent_nfc->d_type = res->d_type;
 151
 152                 if ((precomposed_unicode == 1) && has_non_ascii(res->d_name, (size_t)-1, NULL)) {
 153                         if (prec_dir->ic_precompose == (iconv_t)-1) {
 154                                 die("iconv_open(%s,%s) failed, but needed:\n"
 155                                                 "    precomposed unicode is not supported.\n"
 156                                                 "    If you want to use decomposed unicode, run\n"
 157                                                 "    \"git config core.precomposeunicode false\"\n",
 158                                                 repo_encoding, path_encoding);
 159                         } else {
 160                                 iconv_ibp       cp = (iconv_ibp)res->d_name;
 161                                 size_t inleft = namelenz;
 162                                 char *outpos = &prec_dir->dirent_nfc->d_name[0];
 163                                 size_t outsz = prec_dir->dirent_nfc->max_name_len;
 164                                 errno = 0;
 165                                 iconv(prec_dir->ic_precompose, &cp, &inleft, &outpos, &outsz);
 166                                 if (errno || inleft) {
 167                                         /*
 168                                          * iconv() failed and errno could be E2BIG, EILSEQ, EINVAL, EBADF
 169                                          * MacOS X avoids illegal byte sequences.
 170                                          * If they occur on a mounted drive (e.g. NFS) it is not worth to
 171                                          * die() for that, but rather let the user see the original name
 172                                         */
 173                                         namelenz = 0; /* trigger strlcpy */
 174                                 }
 175                         }
 176                 } else
 177                         namelenz = 0;
 178
 179                 if (!namelenz)
 180                         strlcpy(prec_dir->dirent_nfc->d_name, res->d_name,
 181                                                         prec_dir->dirent_nfc->max_name_len);
 182
 183                 errno = ret_errno;
 184                 return prec_dir->dirent_nfc;
 185         }
 186         return NULL;
 187 }
 188
 189
 190 int precompose_utf8_closedir(PREC_DIR *prec_dir)
 191 {
 192         int ret_value;
 193         int ret_errno;
 194         ret_value = closedir(prec_dir->dirp);
 195         ret_errno = errno;
 196         if (prec_dir->ic_precompose != (iconv_t)-1)
 197                 iconv_close(prec_dir->ic_precompose);
 198         free(prec_dir->dirent_nfc);
 199         free(prec_dir);
 200         errno = ret_errno;
 201         return ret_value;
 202 }