gio/xdgmime/xdgmimemagic.c

   1 /* -*- mode: C; c-file-style: "gnu" -*- */
   2 /* xdgmimemagic.: Private file.  Datastructure for storing magic files.
   3  *
   4  * More info can be found at http://www.freedesktop.org/standards/
   5  *
   6  * Copyright (C) 2003  Red Hat, Inc.
   7  * Copyright (C) 2003  Jonathan Blandford <jrb@alum.mit.edu>
   8  *
   9  * Licensed under the Academic Free License version 2.0
  10  * Or under the following terms:
  11  *
  12  * This library is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU Lesser General Public
  14  * License as published by the Free Software Foundation; either
  15  * version 2.1 of the License, or (at your option) any later version.
  16  *
  17  * This library is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * Lesser General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public
  23  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  24  */
  25
  26 #ifdef HAVE_CONFIG_H
  27 #include "config.h"
  28 #endif
  29
  30 #include <assert.h>
  31 #include "xdgmimemagic.h"
  32 #include "xdgmimeint.h"
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <ctype.h>
  37 #include <errno.h>
  38 #include <limits.h>
  39
  40 #ifndef FALSE
  41 #define FALSE   (0)
  42 #endif
  43
  44 #ifndef TRUE
  45 #define TRUE    (!FALSE)
  46 #endif
  47
  48 #if !defined getc_unlocked && !defined HAVE_GETC_UNLOCKED
  49 # define getc_unlocked(fp) getc (fp)
  50 #endif
  51
  52 typedef struct XdgMimeMagicMatch XdgMimeMagicMatch;
  53 typedef struct XdgMimeMagicMatchlet XdgMimeMagicMatchlet;
  54
  55 typedef enum
  56 {
  57   XDG_MIME_MAGIC_SECTION,
  58   XDG_MIME_MAGIC_MAGIC,
  59   XDG_MIME_MAGIC_ERROR,
  60   XDG_MIME_MAGIC_EOF
  61 } XdgMimeMagicState;
  62
  63 struct XdgMimeMagicMatch
  64 {
  65   const char *mime_type;
  66   int priority;
  67   XdgMimeMagicMatchlet *matchlet;
  68   XdgMimeMagicMatch *next;
  69 };
  70
  71
  72 struct XdgMimeMagicMatchlet
  73 {
  74   int indent;
  75   int offset;
  76   unsigned int value_length;
  77   unsigned char *value;
  78   unsigned char *mask;
  79   unsigned int range_length;
  80   unsigned int word_size;
  81   XdgMimeMagicMatchlet *next;
  82 };
  83
  84
  85 struct XdgMimeMagic
  86 {
  87   XdgMimeMagicMatch *match_list;
  88   int max_extent;
  89 };
  90
  91 static XdgMimeMagicMatch *
  92 _xdg_mime_magic_match_new (void)
  93 {
  94   return calloc (1, sizeof (XdgMimeMagicMatch));
  95 }
  96
  97
  98 static XdgMimeMagicMatchlet *
  99 _xdg_mime_magic_matchlet_new (void)
 100 {
 101   XdgMimeMagicMatchlet *matchlet;
 102
 103   matchlet = malloc (sizeof (XdgMimeMagicMatchlet));
 104
 105   matchlet->indent = 0;
 106   matchlet->offset = 0;
 107   matchlet->value_length = 0;
 108   matchlet->value = NULL;
 109   matchlet->mask = NULL;
 110   matchlet->range_length = 1;
 111   matchlet->word_size = 1;
 112   matchlet->next = NULL;
 113
 114   return matchlet;
 115 }
 116
 117
 118 static void
 119 _xdg_mime_magic_matchlet_free (XdgMimeMagicMatchlet *mime_magic_matchlet)
 120 {
 121   if (mime_magic_matchlet)
 122     {
 123       if (mime_magic_matchlet->next)
 124         _xdg_mime_magic_matchlet_free (mime_magic_matchlet->next);
 125       if (mime_magic_matchlet->value)
 126         free (mime_magic_matchlet->value);
 127       if (mime_magic_matchlet->mask)
 128         free (mime_magic_matchlet->mask);
 129       free (mime_magic_matchlet);
 130     }
 131 }
 132
 133
 134 /* Frees mime_magic_match and the remainder of its list
 135  */
 136 static void
 137 _xdg_mime_magic_match_free (XdgMimeMagicMatch *mime_magic_match)
 138 {
 139   XdgMimeMagicMatch *ptr, *next;
 140
 141   ptr = mime_magic_match;
 142   while (ptr)
 143     {
 144       next = ptr->next;
 145
 146       if (ptr->mime_type)
 147         free ((void *) ptr->mime_type);
 148       if (ptr->matchlet)
 149         _xdg_mime_magic_matchlet_free (ptr->matchlet);
 150       free (ptr);
 151
 152       ptr = next;
 153     }
 154 }
 155
 156 /* Reads in a hunk of data until a newline character or a '\000' is hit.  The
 157  * returned string is null terminated, and doesn't include the newline.
 158  */
 159 static unsigned char *
 160 _xdg_mime_magic_read_to_newline (FILE *magic_file,
 161                                  int  *end_of_file)
 162 {
 163   unsigned char *retval;
 164   int c;
 165   int len, pos;
 166
 167   len = 128;
 168   pos = 0;
 169   retval = malloc (len);
 170   *end_of_file = FALSE;
 171
 172   while (TRUE)
 173     {
 174       c = getc_unlocked (magic_file);
 175       if (c == EOF)
 176         {
 177           *end_of_file = TRUE;
 178           break;
 179         }
 180       if (c == '\n' || c == '\000')
 181         break;
 182       retval[pos++] = (unsigned char) c;
 183       if (pos % 128 == 127)
 184         {
 185           len = len + 128;
 186           retval = realloc (retval, len);
 187         }
 188     }
 189
 190   retval[pos] = '\000';
 191   return retval;
 192 }
 193
 194 /* Returns the number read from the file, or -1 if no number could be read.
 195  */
 196 static int
 197 _xdg_mime_magic_read_a_number (FILE *magic_file,
 198                                int  *end_of_file)
 199 {
 200   /* LONG_MAX is about 20 characters on my system */
 201 #define MAX_NUMBER_SIZE 30
 202   char number_string[MAX_NUMBER_SIZE + 1];
 203   int pos = 0;
 204   int c;
 205   long retval = -1;
 206
 207   while (TRUE)
 208     {
 209       c = getc_unlocked (magic_file);
 210
 211       if (c == EOF)
 212         {
 213           *end_of_file = TRUE;
 214           break;
 215         }
 216       if (! isdigit (c))
 217         {
 218           ungetc (c, magic_file);
 219           break;
 220         }
 221       number_string[pos] = (char) c;
 222       pos++;
 223       if (pos == MAX_NUMBER_SIZE)
 224         break;
 225     }
 226   if (pos > 0)
 227     {
 228       number_string[pos] = '\000';
 229       errno = 0;
 230       retval = strtol (number_string, NULL, 10);
 231
 232       if ((retval < INT_MIN) || (retval > INT_MAX) || (errno != 0))
 233         return -1;
 234     }
 235
 236   return retval;
 237 }
 238
 239 /* Headers are of the format:
 240  * [<priority>:<mime-type>]
 241  */
 242 static XdgMimeMagicState
 243 _xdg_mime_magic_parse_header (FILE *magic_file, XdgMimeMagicMatch *match)
 244 {
 245   int c;
 246   char *buffer;
 247   char *end_ptr;
 248   int end_of_file = 0;
 249
 250   assert (magic_file != NULL);
 251   assert (match != NULL);
 252
 253   c = getc_unlocked (magic_file);
 254   if (c == EOF)
 255     return XDG_MIME_MAGIC_EOF;
 256   if (c != '[')
 257     return XDG_MIME_MAGIC_ERROR;
 258
 259   match->priority = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
 260   if (end_of_file)
 261     return XDG_MIME_MAGIC_EOF;
 262   if (match->priority == -1)
 263     return XDG_MIME_MAGIC_ERROR;
 264
 265   c = getc_unlocked (magic_file);
 266   if (c == EOF)
 267     return XDG_MIME_MAGIC_EOF;
 268   if (c != ':')
 269     return XDG_MIME_MAGIC_ERROR;
 270
 271   buffer = (char *)_xdg_mime_magic_read_to_newline (magic_file, &end_of_file);
 272   if (end_of_file)
 273     {
 274       free (buffer);
 275       return XDG_MIME_MAGIC_EOF;
 276     }
 277
 278   end_ptr = buffer;
 279   while (*end_ptr != ']' && *end_ptr != '\000' && *end_ptr != '\n')
 280     end_ptr++;
 281   if (*end_ptr != ']')
 282     {
 283       free (buffer);
 284       return XDG_MIME_MAGIC_ERROR;
 285     }
 286   *end_ptr = '\000';
 287
 288   match->mime_type = strdup (buffer);
 289   free (buffer);
 290
 291   return XDG_MIME_MAGIC_MAGIC;
 292 }
 293
 294 static XdgMimeMagicState
 295 _xdg_mime_magic_parse_error (FILE *magic_file)
 296 {
 297   int c;
 298
 299   while (1)
 300     {
 301       c = getc_unlocked (magic_file);
 302       if (c == EOF)
 303         return XDG_MIME_MAGIC_EOF;
 304       if (c == '\n')
 305         return XDG_MIME_MAGIC_SECTION;
 306     }
 307 }
 308
 309 /* Headers are of the format:
 310  * [ indent ] ">" start-offset "=" value
 311  * [ "&" mask ] [ "~" word-size ] [ "+" range-length ] "\n"
 312  */
 313 static XdgMimeMagicState
 314 _xdg_mime_magic_parse_magic_line (FILE              *magic_file,
 315                                   XdgMimeMagicMatch *match)
 316 {
 317   XdgMimeMagicMatchlet *matchlet;
 318   int c;
 319   int end_of_file;
 320   int indent = 0;
 321   int bytes_read;
 322
 323   assert (magic_file != NULL);
 324
 325   /* Sniff the buffer to make sure it's a valid line */
 326   c = getc_unlocked (magic_file);
 327   if (c == EOF)
 328     return XDG_MIME_MAGIC_EOF;
 329   else if (c == '[')
 330     {
 331       ungetc (c, magic_file);
 332       return XDG_MIME_MAGIC_SECTION;
 333     }
 334   else if (c == '\n')
 335     return XDG_MIME_MAGIC_MAGIC;
 336
 337   /* At this point, it must be a digit or a '>' */
 338   end_of_file = FALSE;
 339   if (isdigit (c))
 340     {
 341       ungetc (c, magic_file);
 342       indent = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
 343       if (end_of_file)
 344         return XDG_MIME_MAGIC_EOF;
 345       if (indent == -1)
 346         return XDG_MIME_MAGIC_ERROR;
 347       c = getc_unlocked (magic_file);
 348       if (c == EOF)
 349         return XDG_MIME_MAGIC_EOF;
 350     }
 351
 352   if (c != '>')
 353     return XDG_MIME_MAGIC_ERROR;
 354
 355   matchlet = _xdg_mime_magic_matchlet_new ();
 356   matchlet->indent = indent;
 357   matchlet->offset = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
 358   if (end_of_file)
 359     {
 360       _xdg_mime_magic_matchlet_free (matchlet);
 361       return XDG_MIME_MAGIC_EOF;
 362     }
 363   if (matchlet->offset == -1)
 364     {
 365       _xdg_mime_magic_matchlet_free (matchlet);
 366       return XDG_MIME_MAGIC_ERROR;
 367     }
 368   c = getc_unlocked (magic_file);
 369   if (c == EOF)
 370     {
 371       _xdg_mime_magic_matchlet_free (matchlet);
 372       return XDG_MIME_MAGIC_EOF;
 373     }
 374   else if (c != '=')
 375     {
 376       _xdg_mime_magic_matchlet_free (matchlet);
 377       return XDG_MIME_MAGIC_ERROR;
 378     }
 379
 380   /* Next two bytes determine how long the value is */
 381   matchlet->value_length = 0;
 382   c = getc_unlocked (magic_file);
 383   if (c == EOF)
 384     {
 385       _xdg_mime_magic_matchlet_free (matchlet);
 386       return XDG_MIME_MAGIC_EOF;
 387     }
 388   matchlet->value_length = c & 0xFF;
 389   matchlet->value_length = matchlet->value_length << 8;
 390
 391   c = getc_unlocked (magic_file);
 392   if (c == EOF)
 393     {
 394       _xdg_mime_magic_matchlet_free (matchlet);
 395       return XDG_MIME_MAGIC_EOF;
 396     }
 397   matchlet->value_length = matchlet->value_length + (c & 0xFF);
 398
 399   matchlet->value = malloc (matchlet->value_length);
 400
 401   /* OOM */
 402   if (matchlet->value == NULL)
 403     {
 404       _xdg_mime_magic_matchlet_free (matchlet);
 405       return XDG_MIME_MAGIC_ERROR;
 406     }
 407   bytes_read = fread (matchlet->value, 1, matchlet->value_length, magic_file);
 408   if (bytes_read != matchlet->value_length)
 409     {
 410       _xdg_mime_magic_matchlet_free (matchlet);
 411       if (feof (magic_file))
 412         return XDG_MIME_MAGIC_EOF;
 413       else
 414         return XDG_MIME_MAGIC_ERROR;
 415     }
 416
 417   c = getc_unlocked (magic_file);
 418   if (c == '&')
 419     {
 420       matchlet->mask = malloc (matchlet->value_length);
 421       /* OOM */
 422       if (matchlet->mask == NULL)
 423         {
 424           _xdg_mime_magic_matchlet_free (matchlet);
 425           return XDG_MIME_MAGIC_ERROR;
 426         }
 427       bytes_read = fread (matchlet->mask, 1, matchlet->value_length, magic_file);
 428       if (bytes_read != matchlet->value_length)
 429         {
 430           _xdg_mime_magic_matchlet_free (matchlet);
 431           if (feof (magic_file))
 432             return XDG_MIME_MAGIC_EOF;
 433           else
 434             return XDG_MIME_MAGIC_ERROR;
 435         }
 436       c = getc_unlocked (magic_file);
 437     }
 438
 439   if (c == '~')
 440     {
 441       matchlet->word_size = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
 442       if (end_of_file)
 443         {
 444           _xdg_mime_magic_matchlet_free (matchlet);
 445           return XDG_MIME_MAGIC_EOF;
 446         }
 447       if (matchlet->word_size != 0 &&
 448           matchlet->word_size != 1 &&
 449           matchlet->word_size != 2 &&
 450           matchlet->word_size != 4)
 451         {
 452           _xdg_mime_magic_matchlet_free (matchlet);
 453           return XDG_MIME_MAGIC_ERROR;
 454         }
 455       c = getc_unlocked (magic_file);
 456     }
 457
 458   if (c == '+')
 459     {
 460       matchlet->range_length = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
 461       if (end_of_file)
 462         {
 463           _xdg_mime_magic_matchlet_free (matchlet);
 464           return XDG_MIME_MAGIC_EOF;
 465         }
 466       if (matchlet->range_length == -1)
 467         {
 468           _xdg_mime_magic_matchlet_free (matchlet);
 469           return XDG_MIME_MAGIC_ERROR;
 470         }
 471       c = getc_unlocked (magic_file);
 472     }
 473
 474
 475   if (c == '\n')
 476     {
 477       /* We clean up the matchlet, byte swapping if needed */
 478       if (matchlet->word_size > 1)
 479         {
 480 #if LITTLE_ENDIAN
 481           int i;
 482 #endif
 483           if (matchlet->value_length % matchlet->word_size != 0)
 484             {
 485               _xdg_mime_magic_matchlet_free (matchlet);
 486               return XDG_MIME_MAGIC_ERROR;
 487             }
 488           /* FIXME: need to get this defined in a <config.h> style file */
 489 #if LITTLE_ENDIAN
 490           for (i = 0; i < matchlet->value_length; i = i + matchlet->word_size)
 491             {
 492               if (matchlet->word_size == 2)
 493                 *((xdg_uint16_t *) matchlet->value + i) = SWAP_BE16_TO_LE16 (*((xdg_uint16_t *) (matchlet->value + i)));
 494               else if (matchlet->word_size == 4)
 495                 *((xdg_uint32_t *) matchlet->value + i) = SWAP_BE32_TO_LE32 (*((xdg_uint32_t *) (matchlet->value + i)));
 496               if (matchlet->mask)
 497                 {
 498                   if (matchlet->word_size == 2)
 499                     *((xdg_uint16_t *) matchlet->mask + i) = SWAP_BE16_TO_LE16 (*((xdg_uint16_t *) (matchlet->mask + i)));
 500                   else if (matchlet->word_size == 4)
 501                     *((xdg_uint32_t *) matchlet->mask + i) = SWAP_BE32_TO_LE32 (*((xdg_uint32_t *) (matchlet->mask + i)));
 502
 503                 }
 504             }
 505 #endif
 506         }
 507
 508       matchlet->next = match->matchlet;
 509       match->matchlet = matchlet;
 510
 511
 512       return XDG_MIME_MAGIC_MAGIC;
 513     }
 514
 515   _xdg_mime_magic_matchlet_free (matchlet);
 516   if (c == EOF)
 517     return XDG_MIME_MAGIC_EOF;
 518
 519   return XDG_MIME_MAGIC_ERROR;
 520 }
 521
 522 static int
 523 _xdg_mime_magic_matchlet_compare_to_data (XdgMimeMagicMatchlet *matchlet,
 524                                           const void           *data,
 525                                           size_t                len)
 526 {
 527   int i, j;
 528   for (i = matchlet->offset; i < matchlet->offset + matchlet->range_length; i++)
 529     {
 530       int valid_matchlet = TRUE;
 531
 532       if (i + matchlet->value_length > len)
 533         return FALSE;
 534
 535       if (matchlet->mask)
 536         {
 537           for (j = 0; j < matchlet->value_length; j++)
 538             {
 539               if ((matchlet->value[j] & matchlet->mask[j]) !=
 540                   ((((unsigned char *) data)[j + i]) & matchlet->mask[j]))
 541                 {
 542                   valid_matchlet = FALSE;
 543                   break;
 544                 }
 545             }
 546         }
 547       else
 548         {
 549           for (j = 0; j <  matchlet->value_length; j++)
 550             {
 551               if (matchlet->value[j] != ((unsigned char *) data)[j + i])
 552                 {
 553                   valid_matchlet = FALSE;
 554                   break;
 555                 }
 556             }
 557         }
 558       if (valid_matchlet)
 559         return TRUE;
 560     }
 561   return FALSE;
 562 }
 563
 564 static int
 565 _xdg_mime_magic_matchlet_compare_level (XdgMimeMagicMatchlet *matchlet,
 566                                         const void           *data,
 567                                         size_t                len,
 568                                         int                   indent)
 569 {
 570   while ((matchlet != NULL) && (matchlet->indent == indent))
 571     {
 572       if (_xdg_mime_magic_matchlet_compare_to_data (matchlet, data, len))
 573         {
 574           if ((matchlet->next == NULL) ||
 575               (matchlet->next->indent <= indent))
 576             return TRUE;
 577
 578           if (_xdg_mime_magic_matchlet_compare_level (matchlet->next,
 579                                                       data,
 580                                                       len,
 581                                                       indent + 1))
 582             return TRUE;
 583         }
 584
 585       do
 586         {
 587           matchlet = matchlet->next;
 588         }
 589       while (matchlet && matchlet->indent > indent);
 590     }
 591
 592   return FALSE;
 593 }
 594
 595 static int
 596 _xdg_mime_magic_match_compare_to_data (XdgMimeMagicMatch *match,
 597                                        const void        *data,
 598                                        size_t             len)
 599 {
 600   return _xdg_mime_magic_matchlet_compare_level (match->matchlet, data, len, 0);
 601 }
 602
 603 static void
 604 _xdg_mime_magic_insert_match (XdgMimeMagic      *mime_magic,
 605                               XdgMimeMagicMatch *match)
 606 {
 607   XdgMimeMagicMatch *list;
 608
 609   if (mime_magic->match_list == NULL)
 610     {
 611       mime_magic->match_list = match;
 612       return;
 613     }
 614
 615   if (match->priority > mime_magic->match_list->priority)
 616     {
 617       match->next = mime_magic->match_list;
 618       mime_magic->match_list = match;
 619       return;
 620     }
 621
 622   list = mime_magic->match_list;
 623   while (list->next != NULL)
 624     {
 625       if (list->next->priority < match->priority)
 626         {
 627           match->next = list->next;
 628           list->next = match;
 629           return;
 630         }
 631       list = list->next;
 632     }
 633   list->next = match;
 634   match->next = NULL;
 635 }
 636
 637 XdgMimeMagic *
 638 _xdg_mime_magic_new (void)
 639 {
 640   return calloc (1, sizeof (XdgMimeMagic));
 641 }
 642
 643 void
 644 _xdg_mime_magic_free (XdgMimeMagic *mime_magic)
 645 {
 646   if (mime_magic) {
 647     _xdg_mime_magic_match_free (mime_magic->match_list);
 648     free (mime_magic);
 649   }
 650 }
 651
 652 int
 653 _xdg_mime_magic_get_buffer_extents (XdgMimeMagic *mime_magic)
 654 {
 655   return mime_magic->max_extent;
 656 }
 657
 658 const char *
 659 _xdg_mime_magic_lookup_data (XdgMimeMagic *mime_magic,
 660                              const void   *data,
 661                              size_t        len,
 662                              int           *result_prio,
 663                              const char   *mime_types[],
 664                              int           n_mime_types)
 665 {
 666   XdgMimeMagicMatch *match;
 667   const char *mime_type;
 668   int n;
 669   int prio;
 670
 671   prio = 0;
 672   mime_type = NULL;
 673   for (match = mime_magic->match_list; match; match = match->next)
 674     {
 675       if (_xdg_mime_magic_match_compare_to_data (match, data, len))
 676         {
 677           prio = match->priority;
 678           mime_type = match->mime_type;
 679           break;
 680         }
 681       else
 682         {
 683           for (n = 0; n < n_mime_types; n++)
 684             {
 685               if (mime_types[n] &&
 686                   _xdg_mime_mime_type_equal (mime_types[n], match->mime_type))
 687                 mime_types[n] = NULL;
 688             }
 689         }
 690     }
 691
 692   if (mime_type == NULL)
 693     {
 694       for (n = 0; n < n_mime_types; n++)
 695         {
 696           if (mime_types[n])
 697             mime_type = mime_types[n];
 698         }
 699     }
 700
 701   if (result_prio)
 702     *result_prio = prio;
 703
 704   return mime_type;
 705 }
 706
 707 static void
 708 _xdg_mime_update_mime_magic_extents (XdgMimeMagic *mime_magic)
 709 {
 710   XdgMimeMagicMatch *match;
 711   int max_extent = 0;
 712
 713   for (match = mime_magic->match_list; match; match = match->next)
 714     {
 715       XdgMimeMagicMatchlet *matchlet;
 716
 717       for (matchlet = match->matchlet; matchlet; matchlet = matchlet->next)
 718         {
 719           int extent;
 720
 721           extent = matchlet->value_length + matchlet->offset + matchlet->range_length;
 722           if (max_extent < extent)
 723             max_extent = extent;
 724         }
 725     }
 726
 727   mime_magic->max_extent = max_extent;
 728 }
 729
 730 static XdgMimeMagicMatchlet *
 731 _xdg_mime_magic_matchlet_mirror (XdgMimeMagicMatchlet *matchlets)
 732 {
 733   XdgMimeMagicMatchlet *new_list;
 734   XdgMimeMagicMatchlet *tmp;
 735
 736   if ((matchlets == NULL) || (matchlets->next == NULL))
 737     return matchlets;
 738
 739   new_list = NULL;
 740   tmp = matchlets;
 741   while (tmp != NULL)
 742     {
 743       XdgMimeMagicMatchlet *matchlet;
 744
 745       matchlet = tmp;
 746       tmp = tmp->next;
 747       matchlet->next = new_list;
 748       new_list = matchlet;
 749     }
 750
 751   return new_list;
 752
 753 }
 754
 755 static void
 756 _xdg_mime_magic_read_magic_file (XdgMimeMagic *mime_magic,
 757                                  FILE         *magic_file)
 758 {
 759   XdgMimeMagicState state;
 760   XdgMimeMagicMatch *match = NULL; /* Quiet compiler */
 761
 762   state = XDG_MIME_MAGIC_SECTION;
 763
 764   while (state != XDG_MIME_MAGIC_EOF)
 765     {
 766       switch (state)
 767         {
 768         case XDG_MIME_MAGIC_SECTION:
 769           match = _xdg_mime_magic_match_new ();
 770           state = _xdg_mime_magic_parse_header (magic_file, match);
 771           if (state == XDG_MIME_MAGIC_EOF || state == XDG_MIME_MAGIC_ERROR)
 772             _xdg_mime_magic_match_free (match);
 773           break;
 774         case XDG_MIME_MAGIC_MAGIC:
 775           state = _xdg_mime_magic_parse_magic_line (magic_file, match);
 776           if (state == XDG_MIME_MAGIC_SECTION ||
 777               (state == XDG_MIME_MAGIC_EOF && match->mime_type))
 778             {
 779               match->matchlet = _xdg_mime_magic_matchlet_mirror (match->matchlet);
 780               _xdg_mime_magic_insert_match (mime_magic, match);
 781             }
 782           else if (state == XDG_MIME_MAGIC_EOF || state == XDG_MIME_MAGIC_ERROR)
 783             _xdg_mime_magic_match_free (match);
 784           break;
 785         case XDG_MIME_MAGIC_ERROR:
 786           state = _xdg_mime_magic_parse_error (magic_file);
 787           break;
 788         case XDG_MIME_MAGIC_EOF:
 789         default:
 790           /* Make the compiler happy */
 791           assert (0);
 792         }
 793     }
 794   _xdg_mime_update_mime_magic_extents (mime_magic);
 795 }
 796
 797 void
 798 _xdg_mime_magic_read_from_file (XdgMimeMagic *mime_magic,
 799                                 const char   *file_name)
 800 {
 801   FILE *magic_file;
 802   char header[12];
 803
 804   magic_file = fopen (file_name, "r");
 805
 806   if (magic_file == NULL)
 807     return;
 808
 809   if (fread (header, 1, 12, magic_file) == 12)
 810     {
 811       if (memcmp ("MIME-Magic\0\n", header, 12) == 0)
 812         _xdg_mime_magic_read_magic_file (mime_magic, magic_file);
 813     }
 814
 815   fclose (magic_file);
 816 }