Add xdg mime support on Linux.

base/third_party/xdg_mime/xdgmimemagic.c

Index: base/third_party/xdg_mime/xdgmimemagic.c
===================================================================
--- base/third_party/xdg_mime/xdgmimemagic.c	(revision 0)
+++ base/third_party/xdg_mime/xdgmimemagic.c	(revision 0)
@@ -0,0 +1,813 @@
+/* -*- mode: C; c-file-style: "gnu" -*- */
+/* xdgmimemagic.: Private file.  Datastructure for storing magic files.
+ *
+ * More info can be found at http://www.freedesktop.org/standards/
+ *
+ * Copyright (C) 2003  Red Hat, Inc.
+ * Copyright (C) 2003  Jonathan Blandford <jrb@alum.mit.edu>
+ *
+ * Licensed under the Academic Free License version 2.0
+ * Or under the following terms:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <assert.h>
+#include "xdgmimemagic.h"
+#include "xdgmimeint.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+
+#ifndef	FALSE
+#define	FALSE	(0)
+#endif
+
+#ifndef	TRUE
+#define	TRUE	(!FALSE)
+#endif
+
+#if !defined getc_unlocked && !defined HAVE_GETC_UNLOCKED
+# define getc_unlocked(fp) getc (fp)
+#endif
+
+typedef struct XdgMimeMagicMatch XdgMimeMagicMatch;
+typedef struct XdgMimeMagicMatchlet XdgMimeMagicMatchlet;
+
+typedef enum
+{
+  XDG_MIME_MAGIC_SECTION,
+  XDG_MIME_MAGIC_MAGIC,
+  XDG_MIME_MAGIC_ERROR,
+  XDG_MIME_MAGIC_EOF
+} XdgMimeMagicState;
+
+struct XdgMimeMagicMatch
+{
+  const char *mime_type;
+  int priority;
+  XdgMimeMagicMatchlet *matchlet;
+  XdgMimeMagicMatch *next;
+};
+
+
+struct XdgMimeMagicMatchlet
+{
+  int indent;
+  int offset;
+  unsigned int value_length;
+  unsigned char *value;
+  unsigned char *mask;
+  unsigned int range_length;
+  unsigned int word_size;
+  XdgMimeMagicMatchlet *next;
+};
+
+
+struct XdgMimeMagic
+{
+  XdgMimeMagicMatch *match_list;
+  int max_extent;
+};
+
+static XdgMimeMagicMatch *
+_xdg_mime_magic_match_new (void)
+{
+  return calloc (1, sizeof (XdgMimeMagicMatch));
+}
+
+
+static XdgMimeMagicMatchlet *
+_xdg_mime_magic_matchlet_new (void)
+{
+  XdgMimeMagicMatchlet *matchlet;
+
+  matchlet = malloc (sizeof (XdgMimeMagicMatchlet));
+
+  matchlet->indent = 0;
+  matchlet->offset = 0;
+  matchlet->value_length = 0;
+  matchlet->value = NULL;
+  matchlet->mask = NULL;
+  matchlet->range_length = 1;
+  matchlet->word_size = 1;
+  matchlet->next = NULL;
+
+  return matchlet;
+}
+
+
+static void
+_xdg_mime_magic_matchlet_free (XdgMimeMagicMatchlet *mime_magic_matchlet)
+{
+  if (mime_magic_matchlet)
+    {
+      if (mime_magic_matchlet->next)
+	_xdg_mime_magic_matchlet_free (mime_magic_matchlet->next);
+      if (mime_magic_matchlet->value)
+	free (mime_magic_matchlet->value);
+      if (mime_magic_matchlet->mask)
+	free (mime_magic_matchlet->mask);
+      free (mime_magic_matchlet);
+    }
+}
+
+
+/* Frees mime_magic_match and the remainder of its list
+ */
+static void
+_xdg_mime_magic_match_free (XdgMimeMagicMatch *mime_magic_match)
+{
+  XdgMimeMagicMatch *ptr, *next;
+
+  ptr = mime_magic_match;
+  while (ptr)
+    {
+      next = ptr->next;
+
+      if (ptr->mime_type)
+	free ((void *) ptr->mime_type);
+      if (ptr->matchlet)
+	_xdg_mime_magic_matchlet_free (ptr->matchlet);
+      free (ptr);
+
+      ptr = next;
+    }
+}
+
+/* Reads in a hunk of data until a newline character or a '\000' is hit.  The
+ * returned string is null terminated, and doesn't include the newline.
+ */
+static unsigned char *
+_xdg_mime_magic_read_to_newline (FILE *magic_file,
+				 int  *end_of_file)
+{
+  unsigned char *retval;
+  int c;
+  int len, pos;
+
+  len = 128;
+  pos = 0;
+  retval = malloc (len);
+  *end_of_file = FALSE;
+
+  while (TRUE)
+    {
+      c = getc_unlocked (magic_file);
+      if (c == EOF)
+	{
+	  *end_of_file = TRUE;
+	  break;
+	}
+      if (c == '\n' || c == '\000')
+	break;
+      retval[pos++] = (unsigned char) c;
+      if (pos % 128 == 127)
+	{
+	  len = len + 128;
+	  retval = realloc (retval, len);
+	}
+    }
+
+  retval[pos] = '\000';
+  return retval;
+}
+
+/* Returns the number read from the file, or -1 if no number could be read.
+ */
+static int
+_xdg_mime_magic_read_a_number (FILE *magic_file,
+			       int  *end_of_file)
+{
+  /* LONG_MAX is about 20 characters on my system */
+#define MAX_NUMBER_SIZE 30
+  char number_string[MAX_NUMBER_SIZE + 1];
+  int pos = 0;
+  int c;
+  long retval = -1;
+
+  while (TRUE)
+    {
+      c = getc_unlocked (magic_file);
+
+      if (c == EOF)
+	{
+	  *end_of_file = TRUE;
+	  break;
+	}
+      if (! isdigit (c))
+	{
+	  ungetc (c, magic_file);
+	  break;
+	}
+      number_string[pos] = (char) c;
+      pos++;
+      if (pos == MAX_NUMBER_SIZE)
+	break;
+    }
+  if (pos > 0)
+    {
+      number_string[pos] = '\000';
+      errno = 0;
+      retval = strtol (number_string, NULL, 10);
+
+      if ((retval < INT_MIN) || (retval > INT_MAX) || (errno != 0))
+	return -1;
+    }
+
+  return retval;
+}
+
+/* Headers are of the format:
+ * [<priority>:<mime-type>]
+ */
+static XdgMimeMagicState
+_xdg_mime_magic_parse_header (FILE *magic_file, XdgMimeMagicMatch *match)
+{
+  int c;
+  char *buffer;
+  char *end_ptr;
+  int end_of_file = 0;
+
+  assert (magic_file != NULL);
+  assert (match != NULL);
+
+  c = getc_unlocked (magic_file);
+  if (c == EOF)
+    return XDG_MIME_MAGIC_EOF;
+  if (c != '[')
+    return XDG_MIME_MAGIC_ERROR;
+
+  match->priority = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
+  if (end_of_file)
+    return XDG_MIME_MAGIC_EOF;
+  if (match->priority == -1)
+    return XDG_MIME_MAGIC_ERROR;
+
+  c = getc_unlocked (magic_file);
+  if (c == EOF)
+    return XDG_MIME_MAGIC_EOF;
+  if (c != ':')
+    return XDG_MIME_MAGIC_ERROR;
+
+  buffer = (char *)_xdg_mime_magic_read_to_newline (magic_file, &end_of_file);
+  if (end_of_file)
+    return XDG_MIME_MAGIC_EOF;
+
+  end_ptr = buffer;
+  while (*end_ptr != ']' && *end_ptr != '\000' && *end_ptr != '\n')
+    end_ptr++;
+  if (*end_ptr != ']')
+    {
+      free (buffer);
+      return XDG_MIME_MAGIC_ERROR;
+    }
+  *end_ptr = '\000';
+
+  match->mime_type = strdup (buffer);
+  free (buffer);
+
+  return XDG_MIME_MAGIC_MAGIC;
+}
+
+static XdgMimeMagicState
+_xdg_mime_magic_parse_error (FILE *magic_file)
+{
+  int c;
+
+  while (1)
+    {
+      c = getc_unlocked (magic_file);
+      if (c == EOF)
+	return XDG_MIME_MAGIC_EOF;
+      if (c == '\n')
+	return XDG_MIME_MAGIC_SECTION;
+    }
+}
+
+/* Headers are of the format:
+ * [ indent ] ">" start-offset "=" value
+ * [ "&" mask ] [ "~" word-size ] [ "+" range-length ] "\n"
+ */
+static XdgMimeMagicState
+_xdg_mime_magic_parse_magic_line (FILE              *magic_file,
+				  XdgMimeMagicMatch *match)
+{
+  XdgMimeMagicMatchlet *matchlet;
+  int c;
+  int end_of_file;
+  int indent = 0;
+  int bytes_read;
+
+  assert (magic_file != NULL);
+
+  /* Sniff the buffer to make sure it's a valid line */
+  c = getc_unlocked (magic_file);
+  if (c == EOF)
+    return XDG_MIME_MAGIC_EOF;
+  else if (c == '[')
+    {
+      ungetc (c, magic_file);
+      return XDG_MIME_MAGIC_SECTION;
+    }
+  else if (c == '\n')
+    return XDG_MIME_MAGIC_MAGIC;
+
+  /* At this point, it must be a digit or a '>' */
+  end_of_file = FALSE;
+  if (isdigit (c))
+    {
+      ungetc (c, magic_file);
+      indent = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
+      if (end_of_file)
+	return XDG_MIME_MAGIC_EOF;
+      if (indent == -1)
+	return XDG_MIME_MAGIC_ERROR;
+      c = getc_unlocked (magic_file);
+      if (c == EOF)
+	return XDG_MIME_MAGIC_EOF;
+    }
+
+  if (c != '>')
+    return XDG_MIME_MAGIC_ERROR;
+
+  matchlet = _xdg_mime_magic_matchlet_new ();
+  matchlet->indent = indent;
+  matchlet->offset = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
+  if (end_of_file)
+    {
+      _xdg_mime_magic_matchlet_free (matchlet);
+      return XDG_MIME_MAGIC_EOF;
+    }
+  if (matchlet->offset == -1)
+    {
+      _xdg_mime_magic_matchlet_free (matchlet);
+      return XDG_MIME_MAGIC_ERROR;
+    }
+  c = getc_unlocked (magic_file);
+  if (c == EOF)
+    {
+      _xdg_mime_magic_matchlet_free (matchlet);
+      return XDG_MIME_MAGIC_EOF;
+    }
+  else if (c != '=')
+    {
+      _xdg_mime_magic_matchlet_free (matchlet);
+      return XDG_MIME_MAGIC_ERROR;
+    }
+
+  /* Next two bytes determine how long the value is */
+  matchlet->value_length = 0;
+  c = getc_unlocked (magic_file);
+  if (c == EOF)
+    {
+      _xdg_mime_magic_matchlet_free (matchlet);
+      return XDG_MIME_MAGIC_EOF;
+    }
+  matchlet->value_length = c & 0xFF;
+  matchlet->value_length = matchlet->value_length << 8;
+
+  c = getc_unlocked (magic_file);
+  if (c == EOF)
+    {
+      _xdg_mime_magic_matchlet_free (matchlet);
+      return XDG_MIME_MAGIC_EOF;
+    }
+  matchlet->value_length = matchlet->value_length + (c & 0xFF);
+
+  matchlet->value = malloc (matchlet->value_length);
+
+  /* OOM */
+  if (matchlet->value == NULL)
+    {
+      _xdg_mime_magic_matchlet_free (matchlet);
+      return XDG_MIME_MAGIC_ERROR;
+    }
+  bytes_read = fread (matchlet->value, 1, matchlet->value_length, magic_file);
+  if (bytes_read != matchlet->value_length)
+    {
+      _xdg_mime_magic_matchlet_free (matchlet);
+      if (feof (magic_file))
+	return XDG_MIME_MAGIC_EOF;
+      else
+	return XDG_MIME_MAGIC_ERROR;
+    }
+
+  c = getc_unlocked (magic_file);
+  if (c == '&')
+    {
+      matchlet->mask = malloc (matchlet->value_length);
+      /* OOM */
+      if (matchlet->mask == NULL)
+	{
+	  _xdg_mime_magic_matchlet_free (matchlet);
+	  return XDG_MIME_MAGIC_ERROR;
+	}
+      bytes_read = fread (matchlet->mask, 1, matchlet->value_length, magic_file);
+      if (bytes_read != matchlet->value_length)
+	{
+	  _xdg_mime_magic_matchlet_free (matchlet);
+	  if (feof (magic_file))
+	    return XDG_MIME_MAGIC_EOF;
+	  else
+	    return XDG_MIME_MAGIC_ERROR;
+	}
+      c = getc_unlocked (magic_file);
+    }
+
+  if (c == '~')
+    {
+      matchlet->word_size = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
+      if (end_of_file)
+	{
+	  _xdg_mime_magic_matchlet_free (matchlet);
+	  return XDG_MIME_MAGIC_EOF;
+	}
+      if (matchlet->word_size != 0 &&
+	  matchlet->word_size != 1 &&
+	  matchlet->word_size != 2 &&
+	  matchlet->word_size != 4)
+	{
+	  _xdg_mime_magic_matchlet_free (matchlet);
+	  return XDG_MIME_MAGIC_ERROR;
+	}
+      c = getc_unlocked (magic_file);
+    }
+
+  if (c == '+')
+    {
+      matchlet->range_length = _xdg_mime_magic_read_a_number (magic_file, &end_of_file);
+      if (end_of_file)
+	{
+	  _xdg_mime_magic_matchlet_free (matchlet);
+	  return XDG_MIME_MAGIC_EOF;
+	}
+      if (matchlet->range_length == -1)
+	{
+	  _xdg_mime_magic_matchlet_free (matchlet);
+	  return XDG_MIME_MAGIC_ERROR;
+	}
+      c = getc_unlocked (magic_file);
+    }
+
+
+  if (c == '\n')
+    {
+      /* We clean up the matchlet, byte swapping if needed */
+      if (matchlet->word_size > 1)
+	{
+	  int i;
+	  if (matchlet->value_length % matchlet->word_size != 0)
+	    {
+	      _xdg_mime_magic_matchlet_free (matchlet);
+	      return XDG_MIME_MAGIC_ERROR;
+	    }
+	  /* FIXME: need to get this defined in a <config.h> style file */
+#if LITTLE_ENDIAN
+	  for (i = 0; i < matchlet->value_length; i = i + matchlet->word_size)
+	    {
+	      if (matchlet->word_size == 2)
+		*((xdg_uint16_t *) matchlet->value + i) = SWAP_BE16_TO_LE16 (*((xdg_uint16_t *) (matchlet->value + i)));
+	      else if (matchlet->word_size == 4)
+		*((xdg_uint32_t *) matchlet->value + i) = SWAP_BE32_TO_LE32 (*((xdg_uint32_t *) (matchlet->value + i)));
+	      if (matchlet->mask)
+		{
+		  if (matchlet->word_size == 2)
+		    *((xdg_uint16_t *) matchlet->mask + i) = SWAP_BE16_TO_LE16 (*((xdg_uint16_t *) (matchlet->mask + i)));
+		  else if (matchlet->word_size == 4)
+		    *((xdg_uint32_t *) matchlet->mask + i) = SWAP_BE32_TO_LE32 (*((xdg_uint32_t *) (matchlet->mask + i)));
+
+		}
+	    }
+#endif
+	}
+
+      matchlet->next = match->matchlet;
+      match->matchlet = matchlet;
+
+
+      return XDG_MIME_MAGIC_MAGIC;
+    }
+
+  _xdg_mime_magic_matchlet_free (matchlet);
+  if (c == EOF)
+    return XDG_MIME_MAGIC_EOF;
+
+  return XDG_MIME_MAGIC_ERROR;
+}
+
+static int
+_xdg_mime_magic_matchlet_compare_to_data (XdgMimeMagicMatchlet *matchlet,
+					  const void           *data,
+					  size_t                len)
+{
+  int i, j;
+  for (i = matchlet->offset; i < matchlet->offset + matchlet->range_length; i++)
+    {
+      int valid_matchlet = TRUE;
+
+      if (i + matchlet->value_length > len)
+	return FALSE;
+
+      if (matchlet->mask)
+	{
+	  for (j = 0; j < matchlet->value_length; j++)
+	    {
+	      if ((matchlet->value[j] & matchlet->mask[j]) !=
+		  ((((unsigned char *) data)[j + i]) & matchlet->mask[j]))
+		{
+		  valid_matchlet = FALSE;
+		  break;
+		}
+	    }
+	}
+      else
+	{
+	  for (j = 0; j <  matchlet->value_length; j++)
+	    {
+	      if (matchlet->value[j] != ((unsigned char *) data)[j + i])
+		{
+		  valid_matchlet = FALSE;
+		  break;
+		}
+	    }
+	}
+      if (valid_matchlet)
+	return TRUE;
+    }
+  return FALSE;
+}
+
+static int
+_xdg_mime_magic_matchlet_compare_level (XdgMimeMagicMatchlet *matchlet,
+					const void           *data,
+					size_t                len,
+					int                   indent)
+{
+  while ((matchlet != NULL) && (matchlet->indent == indent))
+    {
+      if (_xdg_mime_magic_matchlet_compare_to_data (matchlet, data, len))
+	{
+	  if ((matchlet->next == NULL) ||
+	      (matchlet->next->indent <= indent))
+	    return TRUE;
+
+	  if (_xdg_mime_magic_matchlet_compare_level (matchlet->next,
+						      data,
+						      len,
+						      indent + 1))
+	    return TRUE;
+	}
+
+      do
+	{
+	  matchlet = matchlet->next;
+	}
+      while (matchlet && matchlet->indent > indent);
+    }
+
+  return FALSE;
+}
+
+static int
+_xdg_mime_magic_match_compare_to_data (XdgMimeMagicMatch *match,
+				       const void        *data,
+				       size_t             len)
+{
+  return _xdg_mime_magic_matchlet_compare_level (match->matchlet, data, len, 0);
+}
+
+static void
+_xdg_mime_magic_insert_match (XdgMimeMagic      *mime_magic,
+			      XdgMimeMagicMatch *match)
+{
+  XdgMimeMagicMatch *list;
+
+  if (mime_magic->match_list == NULL)
+    {
+      mime_magic->match_list = match;
+      return;
+    }
+
+  if (match->priority > mime_magic->match_list->priority)
+    {
+      match->next = mime_magic->match_list;
+      mime_magic->match_list = match;
+      return;
+    }
+
+  list = mime_magic->match_list;
+  while (list->next != NULL)
+    {
+      if (list->next->priority < match->priority)
+	{
+	  match->next = list->next;
+	  list->next = match;
+	  return;
+	}
+      list = list->next;
+    }
+  list->next = match;
+  match->next = NULL;
+}
+
+XdgMimeMagic *
+_xdg_mime_magic_new (void)
+{
+  return calloc (1, sizeof (XdgMimeMagic));
+}
+
+void
+_xdg_mime_magic_free (XdgMimeMagic *mime_magic)
+{
+  if (mime_magic) {
+    _xdg_mime_magic_match_free (mime_magic->match_list);
+    free (mime_magic);
+  }
+}
+
+int
+_xdg_mime_magic_get_buffer_extents (XdgMimeMagic *mime_magic)
+{
+  return mime_magic->max_extent;
+}
+
+const char *
+_xdg_mime_magic_lookup_data (XdgMimeMagic *mime_magic,
+			     const void   *data,
+			     size_t        len,
+			     int           *result_prio,
+                             const char   *mime_types[],
+                             int           n_mime_types)
+{
+  XdgMimeMagicMatch *match;
+  const char *mime_type;
+  int n;
+  int prio;
+
+  prio = 0;
+  mime_type = NULL;
+  for (match = mime_magic->match_list; match; match = match->next)
+    {
+      if (_xdg_mime_magic_match_compare_to_data (match, data, len))
+	{
+	  prio = match->priority;
+	  mime_type = match->mime_type;
+	  break;
+	}
+      else 
+	{
+	  for (n = 0; n < n_mime_types; n++)
+	    {
+	      if (mime_types[n] && 
+		  _xdg_mime_mime_type_equal (mime_types[n], match->mime_type))
+		mime_types[n] = NULL;
+	    }
+	}
+    }
+
+  if (mime_type == NULL)
+    {
+      for (n = 0; n < n_mime_types; n++)
+	{
+	  if (mime_types[n])
+	    mime_type = mime_types[n];
+	}
+    }
+  
+  if (result_prio)
+    *result_prio = prio;
+
+  return mime_type;
+}
+
+static void
+_xdg_mime_update_mime_magic_extents (XdgMimeMagic *mime_magic)
+{
+  XdgMimeMagicMatch *match;
+  int max_extent = 0;
+
+  for (match = mime_magic->match_list; match; match = match->next)
+    {
+      XdgMimeMagicMatchlet *matchlet;
+
+      for (matchlet = match->matchlet; matchlet; matchlet = matchlet->next)
+	{
+	  int extent;
+
+	  extent = matchlet->value_length + matchlet->offset + matchlet->range_length;
+	  if (max_extent < extent)
+	    max_extent = extent;
+	}
+    }
+
+  mime_magic->max_extent = max_extent;
+}
+
+static XdgMimeMagicMatchlet *
+_xdg_mime_magic_matchlet_mirror (XdgMimeMagicMatchlet *matchlets)
+{
+  XdgMimeMagicMatchlet *new_list;
+  XdgMimeMagicMatchlet *tmp;
+
+  if ((matchlets == NULL) || (matchlets->next == NULL))
+    return matchlets;
+
+  new_list = NULL;
+  tmp = matchlets;
+  while (tmp != NULL)
+    {
+      XdgMimeMagicMatchlet *matchlet;
+
+      matchlet = tmp;
+      tmp = tmp->next;
+      matchlet->next = new_list;
+      new_list = matchlet;
+    }
+
+  return new_list;
+
+}
+
+static void
+_xdg_mime_magic_read_magic_file (XdgMimeMagic *mime_magic,
+				 FILE         *magic_file)
+{
+  XdgMimeMagicState state;
+  XdgMimeMagicMatch *match = NULL; /* Quiet compiler */
+
+  state = XDG_MIME_MAGIC_SECTION;
+
+  while (state != XDG_MIME_MAGIC_EOF)
+    {
+      switch (state)
+	{
+	case XDG_MIME_MAGIC_SECTION:
+	  match = _xdg_mime_magic_match_new ();
+	  state = _xdg_mime_magic_parse_header (magic_file, match);
+	  if (state == XDG_MIME_MAGIC_EOF || state == XDG_MIME_MAGIC_ERROR)
+	    _xdg_mime_magic_match_free (match);
+	  break;
+	case XDG_MIME_MAGIC_MAGIC:
+	  state = _xdg_mime_magic_parse_magic_line (magic_file, match);
+	  if (state == XDG_MIME_MAGIC_SECTION ||
+	      (state == XDG_MIME_MAGIC_EOF && match->mime_type))
+	    {
+	      match->matchlet = _xdg_mime_magic_matchlet_mirror (match->matchlet);
+	      _xdg_mime_magic_insert_match (mime_magic, match);
+	    }
+	  else if (state == XDG_MIME_MAGIC_EOF || state == XDG_MIME_MAGIC_ERROR)
+	    _xdg_mime_magic_match_free (match);
+	  break;
+	case XDG_MIME_MAGIC_ERROR:
+	  state = _xdg_mime_magic_parse_error (magic_file);
+	  break;
+	case XDG_MIME_MAGIC_EOF:
+	default:
+	  /* Make the compiler happy */
+	  assert (0);
+	}
+    }
+  _xdg_mime_update_mime_magic_extents (mime_magic);
+}
+
+void
+_xdg_mime_magic_read_from_file (XdgMimeMagic *mime_magic,
+				const char   *file_name)
+{
+  FILE *magic_file;
+  char header[12];
+
+  magic_file = fopen (file_name, "r");
+
+  if (magic_file == NULL)
+    return;
+
+  if (fread (header, 1, 12, magic_file) == 12)
+    {
+      if (memcmp ("MIME-Magic\0\n", header, 12) == 0)
+        _xdg_mime_magic_read_magic_file (mime_magic, magic_file);
+    }
+
+  fclose (magic_file);
+}