xdgmime-source/src/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 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, write to the
  24  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25  * Boston, MA 02111-1307, USA.
  26  */
  27
  28 #ifdef HAVE_CONFIG_H
  29 #include <config.h>
  30 #endif
  31
  32 #include <assert.h>
  33 #include "xdgmimemagic.h"
  34 #include "xdgmimeint.h"
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <ctype.h>
  39 #include <errno.h>
  40 #include <limits.h>
  41
  42 #ifndef FALSE
  43 #define FALSE   (0)
  44 #endif
  45
  46 #ifndef TRUE
  47 #define TRUE    (!FALSE)
  48 #endif
  49
  50 #if !defined getc_unlocked && !defined HAVE_GETC_UNLOCKED
  51 # define getc_unlocked(fp) getc (fp)
  52 #endif
  53
  54 typedef struct XdgMimeMagicMatch XdgMimeMagicMatch;
  55 typedef struct XdgMimeMagicMatchlet XdgMimeMagicMatchlet;
  56
  57 typedef enum
  58 {
  59   XDG_MIME_MAGIC_SECTION,
  60   XDG_MIME_MAGIC_MAGIC,
  61   XDG_MIME_MAGIC_ERROR,
  62   XDG_MIME_MAGIC_EOF
  63 } XdgMimeMagicState;
  64
  65 struct XdgMimeMagicMatch
  66 {
  67   const char *mime_type;
  68   int priority;
  69   XdgMimeMagicMatchlet *matchlet;
  70   XdgMimeMagicMatch *next;
  71 };
  72
  73
  74 struct XdgMimeMagicMatchlet
  75 {
  76   int indent;
  77   int offset;
  78   unsigned int value_length;
  79   unsigned char *value;
  80   unsigned char *mask;
  81   unsigned int range_length;
  82   unsigned int word_size;
  83   XdgMimeMagicMatchlet *next;
  84 };
  85
  86
  87 struct XdgMimeMagic
  88 {
  89   XdgMimeMagicMatch *match_list;
  90   int max_extent;
  91 };
  92
  93 static XdgMimeMagicMatch *
  94 _xdg_mime_magic_match_new (void)
  95 {
  96   return calloc (1, sizeof (XdgMimeMagicMatch));
  97 }
  98
  99
 100 static XdgMimeMagicMatchlet *
 101 _xdg_mime_magic_matchlet_new (void)
 102 {
 103   XdgMimeMagicMatchlet *matchlet;
 104
 105   matchlet = malloc (sizeof (XdgMimeMagicMatchlet));
 106
 107   matchlet->indent = 0;
 108   matchlet->offset = 0;
 109   matchlet->value_length = 0;
 110   matchlet->value = NULL;
 111   matchlet->mask = NULL;
 112   matchlet->range_length = 1;
 113   matchlet->word_size = 1;
 114   matchlet->next = NULL;
 115
 116   return matchlet;
 117 }
 118
 119
 120 static void
 121 _xdg_mime_magic_matchlet_free (XdgMimeMagicMatchlet *mime_magic_matchlet)
 122 {
 123   if (mime_magic_matchlet)
 124     {
 125       if (mime_magic_matchlet->next)
 126         _xdg_mime_magic_matchlet_free (mime_magic_matchlet->next);
 127       if (mime_magic_matchlet->value)
 128         free (mime_magic_matchlet->value);
 129       if (mime_magic_matchlet->mask)
 130         free (mime_magic_matchlet->mask);
 131       free (mime_magic_matchlet);
 132     }
 133 }
 134
 135
 136 /* Frees mime_magic_match and the remainder of its list
 137  */
 138 static void
 139 _xdg_mime_magic_match_free (XdgMimeMagicMatch *mime_magic_match)
 140 {
 141   XdgMimeMagicMatch *ptr, *next;
 142
 143   ptr = mime_magic_match;
 144   while (ptr)
 145     {
 146       next = ptr->next;
 147
 148       if (ptr->mime_type)
 149         free ((void *) ptr->mime_type);
 150       if (ptr->matchlet)
 151         _xdg_mime_magic_matchlet_free (ptr->matchlet);
 152       free (ptr);
 153
 154       ptr = next;
 155     }
 156 }
 157
 158 /* Reads in a hunk of data until a newline character or a '\000' is hit.  The
 159  * returned string is null terminated, and doesn't include the newline.
 160  */
 161 static unsigned char *
 162 _xdg_mime_magic_read_to_newline (FILE *magic_file,
 163                                  int  *end_of_file)
 164 {
 165   unsigned char *retval;
 166   int c;
 167   int len, pos;
 168
 169   len = 128;
 170   pos = 0;
 171   retval = malloc (len);
 172   *end_of_file = FALSE;
 173
 174   while (TRUE)
 175     {
 176       c = getc_unlocked (magic_file);
 177       if (c == EOF)
 178         {
 179           *end_of_file = TRUE;
 180           break;
 181         }
 182       if (c == '\n' || c == '\000')
 183         break;
 184       retval[pos++] = (unsigned char) c;
 185       if (pos % 128 == 127)
 186         {
 187           len = len + 128;
 188           retval = realloc (retval, len);
 189         }
 190     }
 191
 192   retval[pos] = '\000';
 193   return retval;
 194 }
 195
 196 /* Returns the number read from the file, or -1 if no number could be read.
 197  */
 198 static int
 199 _xdg_mime_magic_read_a_number (FILE *magic_file,
 200                                int  *end_of_file)
 201 {
 202   /* LONG_MAX is about 20 characters on my system */
 203 #define MAX_NUMBER_SIZE 30
 204   char number_string[MAX_NUMBER_SIZE + 1];
 205   int pos = 0;
 206   int c;
 207   long retval = -1;
 208
 209   while (TRUE)
 210     {
 211       c = getc_unlocked (magic_file);
 212
 213       if (c == EOF)
 214         {
 215           *end_of_file = TRUE;
 216           break;
 217         }
 218       if (! isdigit (c))
 219         {
 220           ungetc (c, magic_file);
 221           break;
 222         }
 223       number_string[pos] = (char) c;
 224       pos++;
 225       if (pos == MAX_NUMBER_SIZE)
 226         break;
 227     }
 228   if (pos > 0)
 229     {
 230       number_string[pos] = '\000';
 231       errno = 0;
 232       retval = strtol (number_string, NULL, 10);
 233
 234       if ((retval < INT_MIN) || (retval > INT_MAX) || (errno != 0))
 235         return -1;
 236     }
 237
 238   return retval;
 239 }
 240
 241 /* Headers are of the format:
 242  * [<priority>:<mime-type>]
 243  */
 244 static XdgMimeMagicState
 245 _xdg_mime_magic_parse_header (FILE *magic_file, XdgMimeMagicMatch *match)
 246 {
 247   int c;
 248   char *buffer;
 249   char *end_ptr;
 250   int end_of_file = 0;
 251
 252   assert (magic_file != NULL);
 253   assert (match != NULL);
 254
 255   c = getc_unlocked (magic_file);
 256   if (c == EOF)
 257     return XDG_MIME_MAGIC_EOF;
 258   if (c != '[')
 259     return XDG_MIME_MAGIC_ERROR;
 260
 261   match->priority = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
 262   if (end_of_file)
 263     return XDG_MIME_MAGIC_EOF;
 264   if (match->priority == -1)
 265     return XDG_MIME_MAGIC_ERROR;
 266
 267   c = getc_unlocked (magic_file);
 268   if (c == EOF)
 269     return XDG_MIME_MAGIC_EOF;
 270   if (c != ':')
 271     return XDG_MIME_MAGIC_ERROR;
 272
 273   buffer = (char *)_xdg_mime_magic_read_to_newline (magic_file, &end_of_file);
 274   if (end_of_file)
 275     {
 276       free (buffer);
 277       return XDG_MIME_MAGIC_EOF;
 278     }
 279
 280   end_ptr = buffer;
 281   while (*end_ptr != ']' && *end_ptr != '\000' && *end_ptr != '\n')
 282     end_ptr++;
 283   if (*end_ptr != ']')
 284     {
 285       free (buffer);
 286       return XDG_MIME_MAGIC_ERROR;
 287     }
 288   *end_ptr = '\000';
 289
 290   match->mime_type = strdup (buffer);
 291   free (buffer);
 292
 293   return XDG_MIME_MAGIC_MAGIC;
 294 }
 295
 296 static XdgMimeMagicState
 297 _xdg_mime_magic_parse_error (FILE *magic_file)
 298 {
 299   int c;
 300
 301   while (1)
 302     {
 303       c = getc_unlocked (magic_file);
 304       if (c == EOF)
 305         return XDG_MIME_MAGIC_EOF;
 306       if (c == '\n')
 307         return XDG_MIME_MAGIC_SECTION;
 308     }
 309 }
 310
 311 /* Headers are of the format:
 312  * [ indent ] ">" start-offset "=" value
 313  * [ "&" mask ] [ "~" word-size ] [ "+" range-length ] "\n"
 314  */
 315 static XdgMimeMagicState
 316 _xdg_mime_magic_parse_magic_line (FILE              *magic_file,
 317                                   XdgMimeMagicMatch *match)
 318 {
 319   XdgMimeMagicMatchlet *matchlet;
 320   int c;
 321   int end_of_file;
 322   int indent = 0;
 323   size_t bytes_read;
 324
 325   assert (magic_file != NULL);
 326
 327   /* Sniff the buffer to make sure it's a valid line */
 328   c = getc_unlocked (magic_file);
 329   if (c == EOF)
 330     return XDG_MIME_MAGIC_EOF;
 331   else if (c == '[')
 332     {
 333       ungetc (c, magic_file);
 334       return XDG_MIME_MAGIC_SECTION;
 335     }
 336   else if (c == '\n')
 337     return XDG_MIME_MAGIC_MAGIC;
 338
 339   /* At this point, it must be a digit or a '>' */
 340   end_of_file = FALSE;
 341   if (isdigit (c))
 342     {
 343       ungetc (c, magic_file);
 344       indent = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
 345       if (end_of_file)
 346         return XDG_MIME_MAGIC_EOF;
 347       if (indent == -1)
 348         return XDG_MIME_MAGIC_ERROR;
 349       c = getc_unlocked (magic_file);
 350       if (c == EOF)
 351         return XDG_MIME_MAGIC_EOF;
 352     }
 353
 354   if (c != '>')
 355     return XDG_MIME_MAGIC_ERROR;
 356
 357   matchlet = _xdg_mime_magic_matchlet_new ();
 358   matchlet->indent = indent;
 359   matchlet->offset = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
 360   if (end_of_file)
 361     {
 362       _xdg_mime_magic_matchlet_free (matchlet);
 363       return XDG_MIME_MAGIC_EOF;
 364     }
 365   if (matchlet->offset == -1)
 366     {
 367       _xdg_mime_magic_matchlet_free (matchlet);
 368       return XDG_MIME_MAGIC_ERROR;
 369     }
 370   c = getc_unlocked (magic_file);
 371   if (c == EOF)
 372     {
 373       _xdg_mime_magic_matchlet_free (matchlet);
 374       return XDG_MIME_MAGIC_EOF;
 375     }
 376   else if (c != '=')
 377     {
 378       _xdg_mime_magic_matchlet_free (matchlet);
 379       return XDG_MIME_MAGIC_ERROR;
 380     }
 381
 382   /* Next two bytes determine how long the value is */
 383   matchlet->value_length = 0;
 384   c = getc_unlocked (magic_file);
 385   if (c == EOF)
 386     {
 387       _xdg_mime_magic_matchlet_free (matchlet);
 388       return XDG_MIME_MAGIC_EOF;
 389     }
 390   matchlet->value_length = c & 0xFF;
 391   matchlet->value_length = matchlet->value_length << 8;
 392
 393   c = getc_unlocked (magic_file);
 394   if (c == EOF)
 395     {
 396       _xdg_mime_magic_matchlet_free (matchlet);
 397       return XDG_MIME_MAGIC_EOF;
 398     }
 399   matchlet->value_length = matchlet->value_length + (c & 0xFF);
 400
 401   matchlet->value = malloc (matchlet->value_length);
 402
 403   /* OOM */
 404   if (matchlet->value == NULL)
 405     {
 406       _xdg_mime_magic_matchlet_free (matchlet);
 407       return XDG_MIME_MAGIC_ERROR;
 408     }
 409   bytes_read = fread (matchlet->value, 1, matchlet->value_length, magic_file);
 410   if (bytes_read != (size_t) matchlet->value_length)
 411     {
 412       _xdg_mime_magic_matchlet_free (matchlet);
 413       if (feof (magic_file))
 414         return XDG_MIME_MAGIC_EOF;
 415       else
 416         return XDG_MIME_MAGIC_ERROR;
 417     }
 418
 419   c = getc_unlocked (magic_file);
 420   if (c == '&')
 421     {
 422       matchlet->mask = malloc (matchlet->value_length);
 423       /* OOM */
 424       if (matchlet->mask == NULL)
 425         {
 426           _xdg_mime_magic_matchlet_free (matchlet);
 427           return XDG_MIME_MAGIC_ERROR;
 428         }
 429       bytes_read = fread (matchlet->mask, 1, matchlet->value_length, magic_file);
 430       if (bytes_read != (size_t) matchlet->value_length)
 431         {
 432           _xdg_mime_magic_matchlet_free (matchlet);
 433           if (feof (magic_file))
 434             return XDG_MIME_MAGIC_EOF;
 435           else
 436             return XDG_MIME_MAGIC_ERROR;
 437         }
 438       c = getc_unlocked (magic_file);
 439     }
 440
 441   if (c == '~')
 442     {
 443       matchlet->word_size = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
 444       if (end_of_file)
 445         {
 446           _xdg_mime_magic_matchlet_free (matchlet);
 447           return XDG_MIME_MAGIC_EOF;
 448         }
 449       if (matchlet->word_size != 0 &&
 450           matchlet->word_size != 1 &&
 451           matchlet->word_size != 2 &&
 452           matchlet->word_size != 4)
 453         {
 454           _xdg_mime_magic_matchlet_free (matchlet);
 455           return XDG_MIME_MAGIC_ERROR;
 456         }
 457       c = getc_unlocked (magic_file);
 458     }
 459
 460   if (c == '+')
 461     {
 462       matchlet->range_length = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
 463       if (end_of_file)
 464         {
 465           _xdg_mime_magic_matchlet_free (matchlet);
 466           return XDG_MIME_MAGIC_EOF;
 467         }
 468       if (matchlet->range_length == (unsigned int) -1)
 469         {
 470           _xdg_mime_magic_matchlet_free (matchlet);
 471           return XDG_MIME_MAGIC_ERROR;
 472         }
 473       c = getc_unlocked (magic_file);
 474     }
 475
 476
 477   if (c == '\n')
 478     {
 479       /* We clean up the matchlet, byte swapping if needed */
 480       if (matchlet->word_size > 1)
 481         {
 482           unsigned int i;
 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   unsigned 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 }