Import of texinfo-3.6 from FSF

1 files changed, 1207 insertions, 0 deletions

diff --git a/gnu/usr.bin/texinfo/info/nodes.c b/gnu/usr.bin/texinfo/info/nodes.c
new file mode 100644
index 00000000000..8995c78195f
--- /dev/null
+++ b/gnu/usr.bin/texinfo/info/nodes.c
@@ -0,0 +1,1207 @@
+/* nodes.c -- How to get an Info file and node. */
+
+/* This file is part of GNU Info, a program for reading online documentation
+   stored in Info format.
+
+   Copyright (C) 1993 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+   Written by Brian Fox (bfox@ai.mit.edu). */
+
+#include <stdio.h>
+#include <ctype.h>
+#include <sys/types.h>
+#if defined (HAVE_SYS_FILE_H)
+#include <sys/file.h>
+#endif /* HAVE_SYS_FILE_H */
+#include <sys/errno.h>
+#include <sys/stat.h>
+#if defined (HAVE_STRING_H)
+#include <string.h>
+#endif /* HAVE_STRING_H */
+#include "nodes.h"
+#include "search.h"
+#include "filesys.h"
+#include "info-utils.h"
+
+#if defined (HANDLE_MAN_PAGES)
+#  include "man.h"
+#endif /* HANDLE_MAN_PAGES */
+
+#if !defined (O_RDONLY)
+#if defined (HAVE_SYS_FCNTL_H)
+#include <sys/fcntl.h>
+#else /* !HAVE_SYS_FCNTL_H */
+#include <fcntl.h>
+#endif /* !HAVE_SYS_FCNTL_H */
+#endif /* !O_RDONLY */
+
+#if !defined (errno)
+extern int errno;
+#endif /* !errno */
+
+/* **************************************************************** */
+/*								    */
+/*		     Functions Static to this File		    */
+/*								    */
+/* **************************************************************** */
+
+static void forget_info_file (), remember_info_file ();
+static void free_file_buffer_tags (), free_info_tag ();
+static void get_nodes_of_tags_table (), get_nodes_of_info_file ();
+static void get_tags_of_indirect_tags_table ();
+static void info_reload_file_buffer_contents ();
+static char *adjust_nodestart ();
+static FILE_BUFFER *info_load_file_internal (), *info_find_file_internal ();
+static NODE *info_node_of_file_buffer_tags ();
+
+static long get_node_length ();
+
+/* Magic number that RMS used to decide how much a tags table pointer could
+   be off by.  I feel that it should be much smaller, like on the order of
+   4. */
+#define DEFAULT_INFO_FUDGE 1000
+
+/* Passed to *_internal functions.  INFO_GET_TAGS says to do what is
+   neccessary to fill in the nodes or tags arrays in FILE_BUFFER. */
+#define INFO_NO_TAGS  0
+#define INFO_GET_TAGS 1
+
+/* **************************************************************** */
+/*								    */
+/*			 Global Variables			    */
+/*								    */
+/* **************************************************************** */
+
+/* When non-zero, this is a string describing the recent file error. */
+char *info_recent_file_error = (char *)NULL;
+
+/* The list of already loaded nodes. */
+FILE_BUFFER **info_loaded_files = (FILE_BUFFER **)NULL;
+
+/* The number of slots currently allocated to LOADED_FILES. */
+int info_loaded_files_slots = 0;
+
+/* **************************************************************** */
+/*								    */
+/*		 Public Functions for Node Manipulation		    */
+/*								    */
+/* **************************************************************** */
+
+/* Used to build "dir" menu from "localdir" files found in INFOPATH. */
+extern void maybe_build_dir_node ();
+
+/* Return a pointer to a NODE structure for the Info node (FILENAME)NODENAME.
+   FILENAME can be passed as NULL, in which case the filename of "dir" is used.
+   NODENAME can be passed as NULL, in which case the nodename of "Top" is used.
+   If the node cannot be found, return a NULL pointer. */
+NODE *
+info_get_node (filename, nodename)
+     char *filename, *nodename;
+{
+  FILE_BUFFER *file_buffer;
+  NODE *node;
+
+  file_buffer = (FILE_BUFFER *)NULL;
+  info_recent_file_error = (char *)NULL;
+
+  info_parse_node (nodename, DONT_SKIP_NEWLINES);
+  nodename = (char *)NULL;
+
+  if (info_parsed_filename)
+    filename = info_parsed_filename;
+
+  if (info_parsed_nodename)
+    nodename = info_parsed_nodename;
+
+  /* If FILENAME is not specified, it defaults to "dir". */
+  if (!filename)
+    filename = "dir";
+
+  /* If the file to be looked up is "dir", build the contents from all of
+     the "dir"s and "localdir"s found in INFOPATH. */
+  if (strcasecmp (filename, "dir") == 0)
+    maybe_build_dir_node (filename);
+
+  /* Find the correct info file. */
+  file_buffer = info_find_file (filename);
+
+  if (!file_buffer)
+    {
+      if (filesys_error_number)
+	info_recent_file_error =
+	  filesys_error_string (filename, filesys_error_number);
+      return ((NODE *)NULL);
+    }
+
+  node = info_get_node_of_file_buffer (nodename, file_buffer);
+  /* If the node looked for was "Top", try again looking for the node under
+     a slightly different name. */
+  if (!node && (nodename == NULL || strcasecmp (nodename, "Top") == 0))
+    {
+      node = info_get_node_of_file_buffer ("Top", file_buffer);
+      if (!node)
+	node = info_get_node_of_file_buffer ("top", file_buffer);
+      if (!node)
+	node = info_get_node_of_file_buffer ("TOP", file_buffer);
+    }
+  return (node);
+}
+
+/* Return a pointer to a NODE structure for the Info node NODENAME in
+   FILE_BUFFER.  NODENAME can be passed as NULL, in which case the
+   nodename of "Top" is used.  If the node cannot be found, return a
+   NULL pointer. */
+NODE *
+info_get_node_of_file_buffer (nodename, file_buffer)
+     char *nodename;
+     FILE_BUFFER *file_buffer;
+{
+  NODE *node = (NODE *)NULL;
+
+  /* If we are unable to find the file, we have to give up.  There isn't
+     anything else we can do. */
+  if (!file_buffer)
+    return ((NODE *)NULL);
+
+  /* If the file buffer was gc'ed, reload the contents now. */
+  if (!file_buffer->contents)
+    info_reload_file_buffer_contents (file_buffer);
+
+  /* If NODENAME is not specified, it defaults to "Top". */
+  if (!nodename)
+    nodename = "Top";
+
+  /* If the name of the node that we wish to find is exactly "*", then the
+     node body is the contents of the entire file.  Create and return such
+     a node. */
+  if (strcmp (nodename, "*") == 0)
+    {
+      node = (NODE *)xmalloc (sizeof (NODE));
+      node->filename = file_buffer->fullpath;
+      node->parent   = (char *)NULL;
+      node->nodename = strdup ("*");
+      node->contents = file_buffer->contents;
+      node->nodelen = file_buffer->filesize;
+      node->flags = 0;
+    }
+#if defined (HANDLE_MAN_PAGES)
+  /* If the file buffer is the magic one associated with manpages, call
+     the manpage node finding function instead. */
+  else if (file_buffer->flags & N_IsManPage)
+    {
+	node = get_manpage_node (file_buffer, nodename);
+    }
+#endif /* HANDLE_MAN_PAGES */
+  /* If this is the "main" info file, it might contain a tags table.  Search
+     the tags table for an entry which matches the node that we want.  If
+     there is a tags table, get the file which contains this node, but don't
+     bother building a node list for it. */
+  else if (file_buffer->tags)
+    {
+      node = info_node_of_file_buffer_tags (file_buffer, nodename);
+    }
+
+  /* Return the results of our node search. */
+  return (node);
+}
+
+/* Locate the file named by FILENAME, and return the information structure
+   describing this file.  The file may appear in our list of loaded files
+   already, or it may not.  If it does not already appear, find the file,
+   and add it to the list of loaded files.  If the file cannot be found,
+   return a NULL FILE_BUFFER *. */
+FILE_BUFFER *
+info_find_file (filename)
+     char *filename;
+{
+  return (info_find_file_internal (filename, INFO_GET_TAGS));
+}
+
+/* Load the info file FILENAME, remembering information about it in a
+   file buffer. */
+FILE_BUFFER *
+info_load_file (filename)
+     char *filename;
+{
+  return (info_load_file_internal (filename, INFO_GET_TAGS));
+}
+
+
+/* **************************************************************** */
+/*								    */
+/*		    Private Functions Implementation		    */
+/*								    */
+/* **************************************************************** */
+
+/* The workhorse for info_find_file ().  Non-zero 2nd argument says to
+   try to build a tags table (or otherwise glean the nodes) for this
+   file once found.  By default, we build the tags table, but when this
+   function is called by info_get_node () when we already have a valid
+   tags table describing the nodes, it is unnecessary. */
+static FILE_BUFFER *
+info_find_file_internal (filename, get_tags)
+     char *filename;
+     int get_tags;
+{
+  register int i;
+  register FILE_BUFFER *file_buffer;
+
+  /* First try to find the file in our list of already loaded files. */
+  if (info_loaded_files)
+    {
+      for (i = 0; file_buffer = info_loaded_files[i]; i++)
+	if ((strcmp (filename, file_buffer->filename) == 0) ||
+	    (strcmp (filename, file_buffer->fullpath) == 0) ||
+	    ((*filename != '/') &&
+	     strcmp (filename,
+		     filename_non_directory (file_buffer->fullpath)) == 0))
+	  {
+	    struct stat new_info, *old_info;
+
+	    /* This file is loaded.  If the filename that we want is
+	       specifically "dir", then simply return the file buffer. */
+	    if (strcasecmp (filename_non_directory (filename), "dir") == 0)
+	      return (file_buffer);
+
+#if defined (HANDLE_MAN_PAGES)
+	    /* Do the same for the magic MANPAGE file. */
+	    if (file_buffer->flags & N_IsManPage)
+	      return (file_buffer);
+#endif /* HANDLE_MAN_PAGES */
+
+	    /* The file appears to be already loaded, and it is not "dir".
+	       Check to see if it has changed since the last time it was
+	       loaded. */
+	    if (stat (file_buffer->fullpath, &new_info) == -1)
+	      {
+		filesys_error_number = errno;
+		return ((FILE_BUFFER *)NULL);
+	      }
+
+	    old_info = &file_buffer->finfo;
+
+	    if ((new_info.st_size != old_info->st_size) ||
+		(new_info.st_mtime != old_info->st_mtime))
+	      {
+		/* The file has changed.  Forget that we ever had loaded it
+		   in the first place. */
+		forget_info_file (filename);
+		break;
+	      }
+	    else
+	      {
+		/* The info file exists, and has not changed since the last
+		   time it was loaded.  If the caller requested a nodes list
+		   for this file, and there isn't one here, build the nodes
+		   for this file_buffer.  In any case, return the file_buffer
+		   object. */
+		if (get_tags && !file_buffer->tags)
+		  build_tags_and_nodes (file_buffer);
+
+		return (file_buffer);
+	      }
+	  }
+    }
+
+  /* The file wasn't loaded.  Try to load it now. */
+#if defined (HANDLE_MAN_PAGES)
+  /* If the name of the file that we want is our special file buffer for
+     Unix manual pages, then create the file buffer, and return it now. */
+  if (strcasecmp (filename, MANPAGE_FILE_BUFFER_NAME) == 0)
+    file_buffer = create_manpage_file_buffer ();
+  else
+#endif /* HANDLE_MAN_PAGES */
+    file_buffer = info_load_file_internal (filename, get_tags);
+
+  /* If the file was loaded, remember the name under which it was found. */
+  if (file_buffer)
+    remember_info_file (file_buffer);
+
+  return (file_buffer);
+}
+
+/* The workhorse function for info_load_file ().  Non-zero second argument
+   says to build a list of tags (or nodes) for this file.  This is the
+   default behaviour when info_load_file () is called, but it is not
+   necessary when loading a subfile for which we already have tags. */
+static FILE_BUFFER *
+info_load_file_internal (filename, get_tags)
+     char *filename;
+     int get_tags;
+{
+  char *fullpath, *contents;
+  long filesize;
+  struct stat finfo;
+  int retcode;
+  FILE_BUFFER *file_buffer = (FILE_BUFFER *)NULL;
+
+  /* Get the full pathname of this file, as known by the info system.
+     That is to say, search along INFOPATH and expand tildes, etc. */
+  fullpath = info_find_fullpath (filename);
+
+  /* Did we actually find the file? */
+  retcode = stat (fullpath, &finfo);
+
+  /* If the file referenced by the name returned from info_find_fullpath ()
+     doesn't exist, then try again with the last part of the filename
+     appearing in lowercase. */
+  if (retcode < 0)
+    {
+      char *lowered_name;
+      char *basename;
+
+      lowered_name = strdup (filename);
+      basename = (char *) strrchr (lowered_name, '/');
+
+      if (basename)
+	basename++;
+      else
+	basename = lowered_name;
+
+      while (*basename)
+	{
+	  if (isupper (*basename))
+	    *basename = tolower (*basename);
+
+	  basename++;
+	}
+
+      fullpath = info_find_fullpath (lowered_name);
+      free (lowered_name);
+
+      retcode = stat (fullpath, &finfo);
+    }
+
+  /* If the file wasn't found, give up, returning a NULL pointer. */
+  if (retcode < 0)
+    {
+      filesys_error_number = errno;
+      return ((FILE_BUFFER *)NULL);
+    }
+
+  /* Otherwise, try to load the file. */
+  contents = filesys_read_info_file (fullpath, &filesize, &finfo);
+
+  if (!contents)
+    return ((FILE_BUFFER *)NULL);
+
+  /* The file was found, and can be read.  Allocate FILE_BUFFER and fill
+     in the various members. */
+  file_buffer = make_file_buffer ();
+  file_buffer->filename = strdup (filename);
+  file_buffer->fullpath = strdup (fullpath);
+  file_buffer->finfo = finfo;
+  file_buffer->filesize = filesize;
+  file_buffer->contents = contents;
+  if (file_buffer->filesize != file_buffer->finfo.st_size)
+    file_buffer->flags |= N_IsCompressed;
+
+  /* If requested, build the tags and nodes for this file buffer. */
+  if (get_tags)
+    build_tags_and_nodes (file_buffer);
+
+  return (file_buffer);
+}
+
+/* Grovel FILE_BUFFER->contents finding tags and nodes, and filling in the
+   various slots.  This can also be used to rebuild a tag or node table. */
+void
+build_tags_and_nodes (file_buffer)
+     FILE_BUFFER *file_buffer;
+{
+  SEARCH_BINDING binding;
+  long position;
+
+  free_file_buffer_tags (file_buffer);
+  file_buffer->flags &= ~N_HasTagsTable;
+
+  /* See if there is a tags table in this info file. */
+  binding.buffer = file_buffer->contents;
+  binding.start = file_buffer->filesize;
+  binding.end = binding.start - 1000;
+  if (binding.end < 0)
+    binding.end = 0;
+  binding.flags = S_FoldCase;
+
+  position = search_backward (TAGS_TABLE_END_LABEL, &binding);
+
+  /* If there is a tag table, find the start of it, and grovel over it
+     extracting tag information. */
+  if (position != -1)
+    while (1)
+      {
+	long tags_table_begin, tags_table_end;
+
+	binding.end = position;
+	binding.start = binding.end - 5 - strlen (TAGS_TABLE_END_LABEL);
+	if (binding.start < 0)
+	  binding.start = 0;
+
+	position = find_node_separator (&binding);
+
+	/* For this test, (and all others here) failure indicates a bogus
+	   tags table.  Grovel the file. */
+	if (position == -1)
+	  break;
+
+	/* Remember the end of the tags table. */
+	binding.start = position;
+	tags_table_end = binding.start;
+	binding.end = 0;
+
+	/* Locate the start of the tags table. */
+	position = search_backward (TAGS_TABLE_BEG_LABEL, &binding);
+
+	if (position == -1)
+	  break;
+
+	binding.end = position;
+	binding.start = binding.end - 5 - strlen (TAGS_TABLE_BEG_LABEL);
+	position = find_node_separator (&binding);
+
+	if (position == -1)
+	  break;
+
+	/* The file contains a valid tags table.  Fill the FILE_BUFFER's
+	   tags member. */
+	file_buffer->flags |= N_HasTagsTable;
+	tags_table_begin = position;
+
+	/* If this isn't an indirect tags table, just remember the nodes
+	   described locally in this tags table.  Note that binding.end
+	   is pointing to just after the beginning label. */
+	binding.start = binding.end;
+	binding.end = file_buffer->filesize;
+
+	if (!looking_at (TAGS_TABLE_IS_INDIRECT_LABEL, &binding))
+	  {
+	    binding.start = tags_table_begin;
+	    binding.end = tags_table_end;
+	    get_nodes_of_tags_table (file_buffer, &binding);
+	    return;
+	  }
+	else
+	  {
+	    /* This is an indirect tags table.  Build TAGS member. */
+	    SEARCH_BINDING indirect;
+
+	    indirect.start = tags_table_begin;
+	    indirect.end = 0;
+	    indirect.buffer = binding.buffer;
+	    indirect.flags = S_FoldCase;
+
+	    position = search_backward (INDIRECT_TAGS_TABLE_LABEL, &indirect);
+
+	    if (position == -1)
+	      {
+		/* This file is malformed.  Give up. */
+		return;
+	      }
+
+	    indirect.start = position;
+	    indirect.end = tags_table_begin;
+	    binding.start = tags_table_begin;
+	    binding.end = tags_table_end;
+	    get_tags_of_indirect_tags_table (file_buffer, &indirect, &binding);
+	    return;
+	  }
+      }
+
+  /* This file doesn't contain any kind of tags table.  Grovel the
+     file and build node entries for it. */
+  get_nodes_of_info_file (file_buffer);
+}
+
+/* Search through FILE_BUFFER->contents building an array of TAG *,
+   one entry per each node present in the file.  Store the tags in
+   FILE_BUFFER->tags, and the number of allocated slots in
+   FILE_BUFFER->tags_slots. */
+static void
+get_nodes_of_info_file (file_buffer)
+     FILE_BUFFER *file_buffer;
+{
+  long nodestart;
+  int tags_index = 0;
+  SEARCH_BINDING binding;
+
+  binding.buffer = file_buffer->contents;
+  binding.start = 0;
+  binding.end = file_buffer->filesize;
+  binding.flags = S_FoldCase;
+
+  while ((nodestart = find_node_separator (&binding)) != -1)
+    {
+      int start, end;
+      char *nodeline;
+      TAG *entry;
+
+      /* Skip past the characters just found. */
+      binding.start = nodestart;
+      binding.start += skip_node_separator (binding.buffer + binding.start);
+
+      /* Move to the start of the line defining the node. */
+      nodeline = binding.buffer + binding.start;
+
+      /* Find "Node:" */
+      start = string_in_line (INFO_NODE_LABEL, nodeline);
+
+      /* If not there, this is not the start of a node. */
+      if (start == -1)
+	continue;
+
+      /* Find the start of the nodename. */
+      start += skip_whitespace (nodeline + start);
+
+      /* Find the end of the nodename. */
+      end = start +
+	skip_node_characters (nodeline + start, DONT_SKIP_NEWLINES);
+
+      /* Okay, we have isolated the node name, and we know where the
+	 node starts.  Remember this information in a NODE structure. */
+      entry = (TAG *)xmalloc (sizeof (TAG));
+      entry->nodename = (char *)xmalloc (1 + (end - start));
+      strncpy (entry->nodename, nodeline + start, end - start);
+      entry->nodename[end - start] = '\0';
+      entry->nodestart = nodestart;
+      {
+	SEARCH_BINDING node_body;
+
+	node_body.buffer = binding.buffer + binding.start;
+	node_body.start = 0;
+	node_body.end = binding.end - binding.start;
+	node_body.flags = S_FoldCase;
+	entry->nodelen = get_node_length (&node_body);
+      }
+
+      entry->filename = file_buffer->fullpath;
+
+      /* Add this tag to the array of tag structures in this FILE_BUFFER. */
+      add_pointer_to_array (entry, tags_index, file_buffer->tags,
+			    file_buffer->tags_slots, 100, TAG *);
+    }
+}
+
+/* Return the length of the node which starts at BINDING. */
+static long
+get_node_length (binding)
+     SEARCH_BINDING *binding;
+{
+  register int i;
+  char *body;
+
+  /* From the Info-RFC file:
+     [A node] ends with either a ^_, a ^L, or the end of file. */
+  for (i = binding->start, body = binding->buffer; i < binding->end; i++)
+    {
+      if (body[i] == INFO_FF || body[i] == INFO_COOKIE)
+	break;
+    }
+  return ((long) i - binding->start);
+}
+
+/* Build and save the array of nodes in FILE_BUFFER by searching through the
+   contents of BUFFER_BINDING for a tags table, and groveling the contents. */
+static void
+get_nodes_of_tags_table (file_buffer, buffer_binding)
+     FILE_BUFFER *file_buffer;
+     SEARCH_BINDING *buffer_binding;
+{
+  int offset, tags_index = 0;
+  SEARCH_BINDING *search;
+  long position;
+
+  search = copy_binding (buffer_binding);
+
+  /* Find the start of the tags table. */
+  position = find_tags_table (search);
+
+  /* If none, we're all done. */
+  if (position == -1)
+    return;
+
+  /* Move to one character before the start of the actual table. */
+  search->start = position;
+  search->start += skip_node_separator (search->buffer + search->start);
+  search->start += strlen (TAGS_TABLE_BEG_LABEL);
+  search->start--;
+
+  /* The tag table consists of lines containing node names and positions.
+     Do each line until we find one that doesn't contain a node name. */
+  while ((position = search_forward ("\n", search)) != -1)
+    {
+      TAG *entry;
+      char *nodedef;
+
+      /* Prepare to skip this line. */
+      search->start = position;
+      search->start++;
+
+      /* Skip past informative "(Indirect)" tags table line. */
+      if (!tags_index && looking_at (TAGS_TABLE_IS_INDIRECT_LABEL, search))
+	continue;
+
+      /* Find the label preceding the node name. */
+      offset =
+	string_in_line (INFO_NODE_LABEL, search->buffer + search->start);
+
+      /* If not there, not a defining line, so we must be out of the
+	 tags table. */
+      if (offset == -1)
+	break;
+
+      /* Point to the beginning of the node definition. */
+      search->start += offset;
+      nodedef = search->buffer + search->start;
+      nodedef += skip_whitespace (nodedef);
+
+      /* Move past the node's name. */
+      for (offset = 0;
+	   (nodedef[offset]) && (nodedef[offset] != INFO_TAGSEP);
+	   offset++);
+
+      if (nodedef[offset] != INFO_TAGSEP)
+	continue;
+
+      entry = (TAG *)xmalloc (sizeof (TAG));
+      entry->nodename = (char *)xmalloc (1 + offset);
+      strncpy (entry->nodename, nodedef, offset);
+      entry->nodename[offset] = '\0';
+      offset++;
+      entry->nodestart = (long) atol (nodedef + offset);
+
+      /* We don't know the length of this node yet. */
+      entry->nodelen = -1;
+
+      /* The filename of this node is currently known as the same as the
+	 name of this file. */
+      entry->filename = file_buffer->fullpath;
+
+      /* Add this node structure to the array of node structures in this
+	 FILE_BUFFER. */
+      add_pointer_to_array (entry, tags_index, file_buffer->tags,
+			    file_buffer->tags_slots, 100, TAG *);
+    }
+  free (search);
+}
+
+/* A structure used only in get_tags_of_indirect_tags_table () to hold onto
+   an intermediate value. */
+typedef struct {
+  char *filename;
+  long first_byte;
+} SUBFILE;
+
+/* Remember in FILE_BUFFER the nodenames, subfilenames, and offsets within the
+   subfiles of every node which appears in TAGS_BINDING.  The 2nd argument is
+   a binding surrounding the indirect files list. */
+static void
+get_tags_of_indirect_tags_table (file_buffer, indirect_binding, tags_binding)
+     FILE_BUFFER *file_buffer;
+     SEARCH_BINDING *indirect_binding, *tags_binding;
+{
+  register int i;
+  SUBFILE **subfiles = (SUBFILE **)NULL;
+  int subfiles_index = 0, subfiles_slots = 0;
+  TAG *entry;
+
+  /* First get the list of tags from the tags table.  Then lookup the
+     associated file in the indirect list for each tag, and update it. */
+  get_nodes_of_tags_table (file_buffer, tags_binding);
+
+  /* We have the list of tags in file_buffer->tags.  Get the list of
+     subfiles from the indirect table. */
+  {
+    char *start, *end, *line;
+    SUBFILE *subfile;
+
+    start = indirect_binding->buffer + indirect_binding->start;
+    end = indirect_binding->buffer + indirect_binding->end;
+    line = start;
+
+    while (line < end)
+      {
+	int colon;
+
+	colon = string_in_line (":", line);
+
+	if (colon == -1)
+	  break;
+
+	subfile = (SUBFILE *)xmalloc (sizeof (SUBFILE));
+	subfile->filename = (char *)xmalloc (colon);
+	strncpy (subfile->filename, line, colon - 1);
+	subfile->filename[colon - 1] = '\0';
+	subfile->first_byte = (long) atol (line + colon);
+
+	add_pointer_to_array
+	  (subfile, subfiles_index, subfiles, subfiles_slots, 10, SUBFILE *);
+
+	while (*line++ != '\n');
+      }
+  }
+
+  /* If we have successfully built the indirect files table, then
+     merge the information in the two tables. */
+  if (!subfiles)
+    {
+      free_file_buffer_tags (file_buffer);
+      return;
+    }
+  else
+    {
+      register int tags_index;
+      long header_length;
+      SEARCH_BINDING binding;
+
+      /* Find the length of the header of the file containing the indirect
+	 tags table.  This header appears at the start of every file.  We
+	 want the absolute position of each node within each subfile, so
+	 we subtract the start of the containing subfile from the logical
+	 position of the node, and then add the length of the header in. */
+      binding.buffer = file_buffer->contents;
+      binding.start = 0;
+      binding.end = file_buffer->filesize;
+      binding.flags = S_FoldCase;
+
+      header_length = find_node_separator (&binding);
+      if (header_length == -1)
+	header_length = 0;
+
+      /* Build the file buffer's list of subfiles. */
+      {
+	char *containing_dir, *temp;
+	int len_containing_dir;
+
+	containing_dir = strdup (file_buffer->fullpath);
+	temp = (char *) strrchr (containing_dir, '/');
+
+	if (temp)
+	  *temp = '\0';
+
+	len_containing_dir = strlen (containing_dir);
+
+	for (i = 0; subfiles[i]; i++);
+
+	file_buffer->subfiles = (char **) xmalloc ((1 + i) * sizeof (char *));
+
+	for (i = 0; subfiles[i]; i++)
+	  {
+	    char *fullpath;
+
+	    fullpath = (char *) xmalloc
+	      (2 + strlen (subfiles[i]->filename) + len_containing_dir);
+
+	    sprintf (fullpath, "%s/%s",
+		     containing_dir, subfiles[i]->filename);
+
+	    file_buffer->subfiles[i] = fullpath;
+	  }
+	file_buffer->subfiles[i] = (char *)NULL;
+	free (containing_dir);
+      }
+
+      /* For each node in the file's tags table, remember the starting
+	 position. */
+      for (tags_index = 0;
+	   entry = file_buffer->tags[tags_index];
+	   tags_index++)
+	{
+	  for (i = 0;
+	       subfiles[i] && entry->nodestart >= subfiles[i]->first_byte;
+	       i++);
+
+	  /* If the Info file containing the indirect tags table is
+	     malformed, then give up. */
+	  if (!i)
+	    {
+	      /* The Info file containing the indirect tags table is
+		 malformed.  Give up. */
+	      for (i = 0; subfiles[i]; i++)
+		{
+		  free (subfiles[i]->filename);
+		  free (subfiles[i]);
+		  free (file_buffer->subfiles[i]);
+		}
+	      file_buffer->subfiles = (char **)NULL;
+	      free_file_buffer_tags (file_buffer);
+	      return;
+	    }
+
+	  /* SUBFILES[i] is the index of the first subfile whose logical
+	     first byte is greater than the logical offset of this node's
+	     starting position.  This means that the subfile directly
+	     preceding this one is the one containing the node. */
+
+	  entry->filename = file_buffer->subfiles[i - 1];
+	  entry->nodestart -= subfiles[i -1]->first_byte;
+	  entry->nodestart += header_length;
+	  entry->nodelen = -1;
+	}
+
+      /* We have successfully built the tags table.  Remember that it
+	 was indirect. */
+      file_buffer->flags |= N_TagsIndirect;
+    }
+
+  /* Free the structures assigned to SUBFILES.  Free the names as well
+     as the structures themselves, then finally, the array. */
+  for (i = 0; subfiles[i]; i++)
+    {
+      free (subfiles[i]->filename);
+      free (subfiles[i]);
+    }
+  free (subfiles);
+}
+
+/* Return the node from FILE_BUFFER which matches NODENAME by searching
+   the tags table in FILE_BUFFER.  If the node could not be found, return
+   a NULL pointer. */
+static NODE *
+info_node_of_file_buffer_tags (file_buffer, nodename)
+     FILE_BUFFER *file_buffer;
+     char *nodename;
+{
+  register int i;
+  TAG *tag;
+
+  for (i = 0; tag = file_buffer->tags[i]; i++)
+    if (strcmp (nodename, tag->nodename) == 0)
+      {
+	FILE_BUFFER *subfile;
+
+	subfile = info_find_file_internal (tag->filename, INFO_NO_TAGS);
+
+	if (!subfile)
+	  return ((NODE *)NULL);
+
+	if (!subfile->contents)
+	  {
+	    info_reload_file_buffer_contents (subfile);
+
+	    if (!subfile->contents)
+	      return ((NODE *)NULL);
+	  }
+
+	/* If we were able to find this file and load it, then return
+	   the node within it. */
+	{
+	  NODE *node;
+
+	  node = (NODE *)xmalloc (sizeof (NODE));
+	  node->filename = (subfile->fullpath);
+	  node->nodename = tag->nodename;
+	  node->contents = subfile->contents + tag->nodestart;
+	  node->flags	 = 0;
+	  node->parent	 = (char *)NULL;
+
+	  if (file_buffer->flags & N_HasTagsTable)
+	    {
+	      node->flags |= N_HasTagsTable;
+
+	      if (file_buffer->flags & N_TagsIndirect)
+		{
+		  node->flags |= N_TagsIndirect;
+		  node->parent = file_buffer->fullpath;
+		}
+	    }
+
+	  if (subfile->flags & N_IsCompressed)
+	    node->flags |= N_IsCompressed;
+
+	  /* If TAG->nodelen hasn't been calculated yet, then we aren't
+	     in a position to trust the entry pointer.  Adjust things so
+	     that ENTRY->nodestart gets the exact address of the start of
+	     the node separator which starts this node, and NODE->contents
+	     gets the address of the line defining this node.  If we cannot
+	     do that, the node isn't really here. */
+	  if (tag->nodelen == -1)
+	    {
+	      int min, max;
+	      char *node_sep;
+	      SEARCH_BINDING node_body;
+	      char *buff_end;
+
+	      min = max = DEFAULT_INFO_FUDGE;
+
+	      if (tag->nodestart < DEFAULT_INFO_FUDGE)
+		min = tag->nodestart;
+
+	      if (DEFAULT_INFO_FUDGE >
+		  (subfile->filesize - tag->nodestart))
+		max = subfile->filesize - tag->nodestart;
+
+	      /* NODE_SEP gets the address of the separator which defines
+		 this node, or (char *)NULL if the node wasn't found.
+		 NODE->contents is side-effected to point to right after
+		 the separator. */
+	      node_sep = adjust_nodestart (node, min, max);
+	      if (node_sep == (char *)NULL)
+		{
+		  free (node);
+		  return ((NODE *)NULL);
+		}
+	      /* Readjust tag->nodestart. */
+	      tag->nodestart = node_sep - subfile->contents;
+
+	      /* Calculate the length of the current node. */
+	      buff_end = subfile->contents + subfile->filesize;
+
+	      node_body.buffer = node->contents;
+	      node_body.start = 0;
+	      node_body.end = buff_end - node_body.buffer;
+	      node_body.flags = 0;
+	      tag->nodelen = get_node_length (&node_body);
+	    }
+	  else
+	    {
+	      /* Since we know the length of this node, we have already
+		 adjusted tag->nodestart to point to the exact start of
+		 it.  Simply skip the node separator. */
+	      node->contents += skip_node_separator (node->contents);
+	    }
+
+	  node->nodelen = tag->nodelen;
+	  return (node);
+	}
+      }
+
+  /* There was a tag table for this file, and the node wasn't found.
+     Return NULL, since this file doesn't contain the desired node. */
+  return ((NODE *)NULL);
+}
+
+/* **************************************************************** */
+/*								    */
+/*		Managing file_buffers, nodes, and tags.		    */
+/*								    */
+/* **************************************************************** */
+
+/* Create a new, empty file buffer. */
+FILE_BUFFER *
+make_file_buffer ()
+{
+  FILE_BUFFER *file_buffer;
+
+  file_buffer = (FILE_BUFFER *)xmalloc (sizeof (FILE_BUFFER));
+  file_buffer->filename = file_buffer->fullpath = (char *)NULL;
+  file_buffer->contents = (char *)NULL;
+  file_buffer->tags = (TAG **)NULL;
+  file_buffer->subfiles = (char **)NULL;
+  file_buffer->tags_slots = 0;
+  file_buffer->flags = 0;
+
+  return (file_buffer);
+}
+
+/* Add FILE_BUFFER to our list of already loaded info files. */
+static void
+remember_info_file (file_buffer)
+     FILE_BUFFER *file_buffer;
+{
+  int i;
+
+  for (i = 0; info_loaded_files && info_loaded_files[i]; i++)
+    ;
+
+  add_pointer_to_array (file_buffer, i, info_loaded_files,
+			info_loaded_files_slots, 10, FILE_BUFFER *);
+}
+
+/* Forget the contents, tags table, nodes list, and names of FILENAME. */
+static void
+forget_info_file (filename)
+     char *filename;
+{
+  register int i;
+  FILE_BUFFER *file_buffer;
+
+  if (!info_loaded_files)
+    return;
+
+  for (i = 0; file_buffer = info_loaded_files[i]; i++)
+    if ((strcmp (filename, file_buffer->filename) == 0) ||
+	(strcmp (filename, file_buffer->fullpath) == 0))
+      {
+	free (file_buffer->filename);
+	free (file_buffer->fullpath);
+
+	if (file_buffer->contents)
+	  free (file_buffer->contents);
+	
+	/* Note that free_file_buffer_tags () also kills the subfiles
+	   list, since the subfiles list is only of use in conjunction
+	   with tags. */
+	free_file_buffer_tags (file_buffer);
+
+	while (info_loaded_files[i] = info_loaded_files[++i])
+	  ;
+
+	break;
+      }
+}
+
+/* Free the tags (if any) associated with FILE_BUFFER. */
+static void
+free_file_buffer_tags (file_buffer)
+     FILE_BUFFER *file_buffer;
+{
+  register int i;
+
+  if (file_buffer->tags)
+    {
+      register TAG *tag;
+
+      for (i = 0; tag = file_buffer->tags[i]; i++)
+	free_info_tag (tag);
+
+      free (file_buffer->tags);
+      file_buffer->tags = (TAG **)NULL;
+      file_buffer->tags_slots = 0;
+    }
+
+  if (file_buffer->subfiles)
+    {
+      for (i = 0; file_buffer->subfiles[i]; i++)
+	free (file_buffer->subfiles[i]);
+
+      free (file_buffer->subfiles);
+      file_buffer->subfiles = (char **)NULL;
+    }
+}
+
+/* Free the data associated with TAG, as well as TAG itself. */
+static void
+free_info_tag (tag)
+     TAG *tag;
+{
+  free (tag->nodename);
+
+  /* We don't free tag->filename, because that filename is part of the
+     subfiles list for the containing FILE_BUFFER.  free_info_tags ()
+     will free the subfiles when it is appropriate. */
+
+  free (tag);
+}
+
+/* Load the contents of FILE_BUFFER->contents.  This function is called
+   when a file buffer was loaded, and then in order to conserve memory, the
+   file buffer's contents were freed and the pointer was zero'ed.  Note that
+   the file was already loaded at least once successfully, so the tags and/or
+   nodes members are still correctly filled. */
+static void
+info_reload_file_buffer_contents (fb)
+     FILE_BUFFER *fb;
+{
+
+#if defined (HANDLE_MAN_PAGES)
+  /* If this is the magic manpage node, don't try to reload, just give up. */
+  if (fb->flags & N_IsManPage)
+    return;
+#endif
+
+  fb->flags &= ~N_IsCompressed;
+
+  /* Let the filesystem do all the work for us. */
+  fb->contents =
+    filesys_read_info_file (fb->fullpath, &(fb->filesize), &(fb->finfo));
+  if (fb->filesize != (long) (fb->finfo.st_size))
+    fb->flags |= N_IsCompressed;
+}
+
+/* Return the actual starting memory location of NODE, side-effecting
+   NODE->contents.  MIN and MAX are bounds for a search if one is necessary.
+   Because of the way that tags are implemented, the physical nodestart may
+   not actually be where the tag says it is.  If that is the case, but the
+   node was found anyway, set N_UpdateTags in NODE->flags.  If the node is
+   found, return non-zero.  NODE->contents is returned positioned right after
+   the node separator that precedes this node, while the return value is
+   position directly on the separator that precedes this node.  If the node
+   could not be found, return a NULL pointer. */
+static char *
+adjust_nodestart (node, min, max)
+     NODE *node;
+     int min, max;
+{
+  long position;
+  SEARCH_BINDING node_body;
+
+  /* Define the node body. */
+  node_body.buffer = node->contents;
+  node_body.start = 0;
+  node_body.end = max;
+  node_body.flags = 0;
+
+  /* Try the optimal case first.  Who knows?  This file may actually be
+     formatted (mostly) correctly. */
+  if (node_body.buffer[0] != INFO_COOKIE && min > 2)
+    node_body.buffer -= 3;
+
+  position = find_node_separator (&node_body);
+
+  /* If we found a node start, then check it out. */
+  if (position != -1)
+    {
+      int sep_len;
+
+      sep_len = skip_node_separator (node->contents);
+
+      /* If we managed to skip a node separator, then check for this node
+	 being the right one. */
+      if (sep_len != 0)
+	{
+	  char *nodedef, *nodestart;
+	  int offset;
+
+	  nodestart = node_body.buffer + position + sep_len;
+	  nodedef = nodestart;
+	  offset = string_in_line (INFO_NODE_LABEL, nodedef);
+
+	  if (offset != -1)
+	    {
+	      nodedef += offset;
+	      nodedef += skip_whitespace (nodedef);
+	      offset = skip_node_characters (nodedef, DONT_SKIP_NEWLINES);
+	      if ((offset == strlen (node->nodename)) &&
+		  (strncmp (node->nodename, nodedef, offset) == 0))
+		{
+		  node->contents = nodestart;
+		  return (node_body.buffer + position);
+		}
+	    }
+	}
+    }
+
+  /* Oh well, I guess we have to try to find it in a larger area. */
+  node_body.buffer = node->contents - min;
+  node_body.start = 0;
+  node_body.end = min + max;
+  node_body.flags = 0;
+
+  position = find_node_in_binding (node->nodename, &node_body);
+
+  /* If the node couldn't be found, we lose big. */
+  if (position == -1)
+    return ((char *)NULL);
+
+  /* Otherwise, the node was found, but the tags table could need updating
+     (if we used a tag to get here, that is).  Set the flag in NODE->flags. */
+  node->contents = node_body.buffer + position;
+  node->contents += skip_node_separator (node->contents);
+  if (node->flags & N_HasTagsTable)
+    node->flags |= N_UpdateTags;
+  return (node_body.buffer + position);
+}