Better comment for chdir_verify_path()

[dragonfly.git] / contrib / cvs-1.12.11 / src / recurse.c

/*
 * Copyright (c) 1992, Brian Berliner and Jeff Polk
 *
 * You may distribute under the terms of the GNU General Public License as
 * specified in the README file that comes with the CVS source distribution.
 *
 * General recursion handler
 *
 */

#include "cvs.h"
#include "save-cwd.h"
#include "fileattr.h"
#include "edit.h"

static int do_dir_proc (Node * p, void *closure);
static int do_file_proc (Node * p, void *closure);
static void addlist (List ** listp, char *key);
static int unroll_files_proc (Node *p, void *closure);
static void addfile (List **listp, char *dir, char *file);

static char *update_dir;
static char *repository = NULL;
static List *filelist = NULL; /* holds list of files on which to operate */
static List *dirlist = NULL; /* holds list of directories on which to operate */

struct recursion_frame {
    FILEPROC fileproc;
    FILESDONEPROC filesdoneproc;
    DIRENTPROC direntproc;
    DIRLEAVEPROC dirleaveproc;
    void *callerdat;
    Dtype flags;
    int which;
    int aflag;
    int locktype;
    int dosrcs;
    char *repository;                   /* Keep track of repository for rtag */
};

static int do_recursion (struct recursion_frame *frame);

/* I am half tempted to shove a struct file_info * into the struct
   recursion_frame (but then we would need to modify or create a
   recursion_frame for each file), or shove a struct recursion_frame *
   into the struct file_info (more tempting, although it isn't completely
   clear that the struct file_info should contain info about recursion
   processor internals).  So instead use this struct.  */

struct frame_and_file {
    struct recursion_frame *frame;
    struct file_info *finfo;
};

/* Similarly, we need to pass the entries list to do_dir_proc.  */

struct frame_and_entries {
    struct recursion_frame *frame;
    List *entries;
};


/* Start a recursive command.
 *
 * INPUT
 *
 *   fileproc
 *     Function called with each file as an argument.
 *
 *   filesdoneproc
 *     Function called after all the files in a directory have been processed,
 *     before subdirectories have been processed.
 *
 *   direntproc
 *     Function called immediately upon entering a directory, before processing
 *     any files or subdirectories.
 *
 *   dirleaveproc
 *     Function called upon finishing a directory, immediately before leaving
 *     it and returning control to the function processing the parent
 *     directory.
 *
 *   callerdat
 *      This void * is passed to the functions above.
 *
 *   argc, argv
 *     The files on which to operate, interpreted as command line arguments.
 *     In the special case of no arguments, defaults to operating on the
 *     current directory (`.').
 *
 *   local
 *
 *   which
 *     specifies the kind of recursion.  There are several cases:
 *
 *       1.  W_LOCAL is not set but W_REPOS or W_ATTIC is.  The current
 *       directory when we are called must be the repository and
 *       recursion proceeds according to what exists in the repository.
 *
 *       2a.  W_LOCAL is set but W_REPOS and W_ATTIC are not.  The
 *       current directory when we are called must be the working
 *       directory.  Recursion proceeds according to what exists in the
 *       working directory, never (I think) consulting any part of the
 *       repository which does not correspond to the working directory
 *       ("correspond" == Name_Repository).
 *
 *       2b.  W_LOCAL is set and so is W_REPOS or W_ATTIC.  This is the
 *       weird one.  The current directory when we are called must be
 *       the working directory.  We recurse through working directories,
 *       but we recurse into a directory if it is exists in the working
 *       directory *or* it exists in the repository.  If a directory
 *       does not exist in the working directory, the direntproc must
 *       either tell us to skip it (R_SKIP_ALL), or must create it (I
 *       think those are the only two cases).
 *
 *   aflag
 *   locktype
 *   update_preload
 *   dosrcs
 *
 *   repository_in
 *     keeps track of the repository string.  This is only for the remote mode,
 *     specifically, r* commands (rtag, rdiff, co, ...) where xgetcwd() was used
 *     to locate the repository.  Things would break when xgetcwd() was used
 *     with a symlinked repository because xgetcwd() would return the true path
 *     and in some cases this would cause the path to be printed as other than
 *     the user specified in error messages and in other cases some of CVS's
 *     security assertions would fail.
 *
 * GLOBALS
 *   ???
 *
 * OUTPUT
 *
 *  callerdat can be modified by the FILEPROC, FILESDONEPROC, DIRENTPROC, and
 *  DIRLEAVEPROC.
 *
 * RETURNS
 *   A count of errors counted by walking the argument list with
 *   unroll_files_proc() and do_recursion().
 *
 * ERRORS
 *   Fatal errors occur:
 *     1.  when there were no arguments and the current directory
 *         does not contain CVS metadata.
 *     2.  when all but the last path element from an argument from ARGV cannot
 *         be found to be a local directory.
 */
int
start_recursion (FILEPROC fileproc, FILESDONEPROC filesdoneproc,
                 DIRENTPROC direntproc, DIRLEAVEPROC dirleaveproc,
                 void *callerdat, int argc, char **argv, int local,
                 int which, int aflag, int locktype,
                 char *update_preload, int dosrcs, char *repository_in)
{
    int i, err = 0;
#ifdef CLIENT_SUPPORT
    List *args_to_send_when_finished = NULL;
#endif
    List *files_by_dir = NULL;
    struct recursion_frame frame;

#ifdef HAVE_PRINTF_PTR
    TRACE ( TRACE_FLOW,
            "start_recursion ( fileproc=%p, filesdoneproc=%p,\n"
       "                       direntproc=%p, dirleavproc=%p,\n"
       "                       callerdat=%p, argc=%d, argv=%p,\n"
       "                       local=%d, which=%d, aflag=%d,\n"
       "                       locktype=%d, update_preload=%s\n"
       "                       dosrcs=%d, repository_in=%s )",
               (void *) fileproc, (void *) filesdoneproc,
               (void *) direntproc, (void *) dirleaveproc,
               (void *) callerdat, argc, (void *) argv,
               local, which, aflag, locktype,
               update_preload ? update_preload : "(null)", dosrcs,
               repository_in ? repository_in : "(null)");
#else
    TRACE ( TRACE_FLOW,
            "start_recursion ( fileproc=%lx, filesdoneproc=%lx,\n"
       "                       direntproc=%lx, dirleavproc=%lx,\n"
       "                       callerdat=%lx, argc=%d, argv=%lx,\n"
       "                       local=%d, which=%d, aflag=%d,\n"
       "                       locktype=%d, update_preload=%s\n"
       "                       dosrcs=%d, repository_in=%s )",
               (unsigned long) fileproc, (unsigned long) filesdoneproc,
               (unsigned long) direntproc, (unsigned long) dirleaveproc,
               (unsigned long) callerdat, argc, (unsigned long) argv,
               local, which, aflag, locktype,
               update_preload ? update_preload : "(null)", dosrcs,
               repository_in ? repository_in : "(null)");
#endif

    frame.fileproc = fileproc;
    frame.filesdoneproc = filesdoneproc;
    frame.direntproc = direntproc;
    frame.dirleaveproc = dirleaveproc;
    frame.callerdat = callerdat;
    frame.flags = local ? R_SKIP_DIRS : R_PROCESS;
    frame.which = which;
    frame.aflag = aflag;
    frame.locktype = locktype;
    frame.dosrcs = dosrcs;

    /* If our repository_in has a trailing "/.", remove it before storing it
     * for do_recursion().
     *
     * FIXME: This is somewhat of a hack in the sense that many of our callers
     * painstakingly compute and add the trailing '.' we now remove.
     */
    while (repository_in && strlen (repository_in) >= 2
           && repository_in[strlen (repository_in) - 2] == '/'
           && repository_in[strlen (repository_in) - 1] == '.')
    {
        /* Beware the case where the string is exactly "/." or "//.".
         * Paths with a leading "//" are special on some early UNIXes.
         */
        if (strlen (repository_in) == 2 || strlen (repository_in) == 3)
            repository_in[strlen (repository_in) - 1] = '\0';
        else
            repository_in[strlen (repository_in) - 2] = '\0';
    }
    frame.repository = repository_in;

    expand_wild (argc, argv, &argc, &argv);

    if (update_preload == NULL)
        update_dir = xstrdup ("");
    else
        update_dir = xstrdup (update_preload);

    /* clean up from any previous calls to start_recursion */
    if (repository)
    {
        free (repository);
        repository = NULL;
    }
    if (filelist)
        dellist (&filelist); /* FIXME-krp: no longer correct. */
    if (dirlist)
        dellist (&dirlist);

#ifdef SERVER_SUPPORT
    if (server_active)
    {
        for (i = 0; i < argc; ++i)
            server_pathname_check (argv[i]);
    }
#endif

    if (argc == 0)
    {
        int just_subdirs = (which & W_LOCAL) && !isdir (CVSADM);

#ifdef CLIENT_SUPPORT
        if (!just_subdirs
            && CVSroot_cmdline == NULL
            && current_parsed_root->isremote)
        {
            cvsroot_t *root = Name_Root (NULL, update_dir);
            if (root)
            {
                if (strcmp (root->original, original_parsed_root->original))
                    /* We're skipping this directory because it is for
                     * a different root.  Therefore, we just want to
                     * do the subdirectories only.  Processing files would
                     * cause a working directory from one repository to be
                     * processed against a different repository, which could
                     * cause all kinds of spurious conflicts and such.
                     *
                     * Question: what about the case of "cvs update foo"
                     * where we process foo/bar and not foo itself?  That
                     * seems to be handled somewhere (else) but why should
                     * it be a separate case?  Needs investigation...  */
                    just_subdirs = 1;
            }
        }
#endif

        /*
         * There were no arguments, so we'll probably just recurse. The
         * exception to the rule is when we are called from a directory
         * without any CVS administration files.  That has always meant to
         * process each of the sub-directories, so we pretend like we were
         * called with the list of sub-dirs of the current dir as args
         */
        if (just_subdirs)
        {
            dirlist = Find_Directories (NULL, W_LOCAL, NULL);
            /* If there are no sub-directories, there is a certain logic in
               favor of doing nothing, but in fact probably the user is just
               confused about what directory they are in, or whether they
               cvs add'd a new directory.  In the case of at least one
               sub-directory, at least when we recurse into them we
               notice (hopefully) whether they are under CVS control.  */
            if (list_isempty (dirlist))
            {
                if (update_dir[0] == '\0')
                    error (0, 0, "in directory .:");
                else
                    error (0, 0, "in directory %s:", update_dir);
                error (1, 0,
                       "there is no version here; run '%s checkout' first",
                       program_name);
            }
#ifdef CLIENT_SUPPORT
            else if (current_parsed_root->isremote && server_started)
            {
                /* In the the case "cvs update foo bar baz", a call to
                   send_file_names in update.c will have sent the
                   appropriate "Argument" commands to the server.  In
                   this case, that won't have happened, so we need to
                   do it here.  While this example uses "update", this
                   generalizes to other commands.  */

                /* This is the same call to Find_Directories as above.
                   FIXME: perhaps it would be better to write a
                   function that duplicates a list. */
                args_to_send_when_finished = Find_Directories (NULL,
                                                               W_LOCAL,
                                                               NULL);
            }
#endif
        }
        else
            addlist (&dirlist, ".");

        goto do_the_work;
    }


    /*
     * There were arguments, so we have to handle them by hand. To do
     * that, we set up the filelist and dirlist with the arguments and
     * call do_recursion.  do_recursion recognizes the fact that the
     * lists are non-null when it starts and doesn't update them.
     *
     * explicitly named directories are stored in dirlist.
     * explicitly named files are stored in filelist.
     * other possibility is named entities whicha are not currently in
     * the working directory.
     */

    for (i = 0; i < argc; i++)
    {
        /* if this argument is a directory, then add it to the list of
           directories. */

        if (!wrap_name_has (argv[i], WRAP_TOCVS) && isdir (argv[i]))
        {
            strip_trailing_slashes (argv[i]);
            addlist (&dirlist, argv[i]);
        }
        else
        {
            /* otherwise, split argument into directory and component names. */
            char *dir;
            char *comp;
            char *file_to_try;

            /* Now break out argv[i] into directory part (DIR) and file part
             * (COMP).  DIR and COMP will each point to a newly malloc'd
             * string.
             */
            dir = xstrdup (argv[i]);
            /* It's okay to cast out last_component's const below since we know
             * we just allocated dir here and have control of it.
             */
            comp = (char *)last_component (dir);
            if (comp == dir)
            {
                /* no dir component.  What we have is an implied "./" */
                dir = xstrdup(".");
            }
            else
            {
                comp[-1] = '\0';
                comp = xstrdup (comp);
            }

            /* if this argument exists as a file in the current
               working directory tree, then add it to the files list.  */

            if (!(which & W_LOCAL))
            {
                /* If doing rtag, we've done a chdir to the repository. */
                file_to_try = xmalloc( strlen( argv[i] )
                                       + sizeof( RCSEXT ) + 1 );
                sprintf (file_to_try, "%s%s", argv[i], RCSEXT);
            }
            else
                file_to_try = xstrdup (argv[i]);

            if (isfile (file_to_try))
                addfile (&files_by_dir, dir, comp);
            else if (isdir (dir))
            {
                if ((which & W_LOCAL) && isdir (CVSADM)
#ifdef CLIENT_SUPPORT
                    && !current_parsed_root->isremote
#endif
                    )
                {
                    /* otherwise, look for it in the repository. */
                    char *tmp_update_dir;
                    char *repos;
                    char *reposfile;

                    tmp_update_dir = xmalloc (strlen (update_dir)
                                              + strlen (dir)
                                              + 5);
                    strcpy (tmp_update_dir, update_dir);

                    if (*tmp_update_dir != '\0')
                        strcat (tmp_update_dir, "/");

                    strcat (tmp_update_dir, dir);

                    /* look for it in the repository. */
                    repos = Name_Repository (dir, tmp_update_dir);
                    reposfile = xmalloc (strlen (repos)
                                         + strlen (comp)
                                         + 5);
                    sprintf (reposfile, "%s/%s", repos, comp);
                    free (repos);

                    if (!wrap_name_has (comp, WRAP_TOCVS) && isdir (reposfile))
                        addlist (&dirlist, argv[i]);
                    else
                        addfile (&files_by_dir, dir, comp);

                    free (tmp_update_dir);
                    free (reposfile);
                }
                else
                    addfile (&files_by_dir, dir, comp);
            }
            else
                error (1, 0, "no such directory `%s'", dir);

            free (file_to_try);
            free (dir);
            free (comp);
        }
    }

    /* At this point we have looped over all named arguments and built
       a coupla lists.  Now we unroll the lists, setting up and
       calling do_recursion. */

    err += walklist (files_by_dir, unroll_files_proc, (void *) &frame);
    dellist(&files_by_dir);

    /* then do_recursion on the dirlist. */
    if (dirlist != NULL)
    {
    do_the_work:
        err += do_recursion (&frame);
    }
        
    /* Free the data which expand_wild allocated.  */
    free_names (&argc, argv);

    free (update_dir);
    update_dir = NULL;

#ifdef CLIENT_SUPPORT
    if (args_to_send_when_finished != NULL)
    {
        /* FIXME (njc): in the multiroot case, we don't want to send
           argument commands for those top-level directories which do
           not contain any subdirectories which have files checked out
           from current_parsed_root.  If we do, and two repositories
           have a module with the same name, nasty things could happen.

           This is hard.  Perhaps we should send the Argument commands
           later in this procedure, after we've had a chance to notice
           which directores we're using (after do_recursion has been
           called once).  This means a _lot_ of rewriting, however.

           What we need to do for that to happen is descend the tree
           and construct a list of directories which are checked out
           from current_cvsroot.  Now, we eliminate from the list all
           of those directories which are immediate subdirectories of
           another directory in the list.  To say that the opposite
           way, we keep the directories which are not immediate
           subdirectories of any other in the list.  Here's a picture:

                              a
                             / \
                            B   C
                           / \
                          D   e
                             / \
                            F   G
                               / \
                              H   I

           The node in capitals are those directories which are
           checked out from current_cvsroot.  We want the list to
           contain B, C, F, and G.  D, H, and I are not included,
           because their parents are also checked out from
           current_cvsroot.

           The algorithm should be:

           1) construct a tree of all directory names where each
           element contains a directory name and a flag which notes if
           that directory is checked out from current_cvsroot

                              a0
                             / \
                            B1  C1
                           / \
                          D1  e0
                             / \
                            F1  G1
                               / \
                              H1  I1

           2) Recursively descend the tree.  For each node, recurse
           before processing the node.  If the flag is zero, do
           nothing.  If the flag is 1, check the node's parent.  If
           the parent's flag is one, change the current entry's flag
           to zero.

                              a0
                             / \
                            B1  C1
                           / \
                          D0  e0
                             / \
                            F1  G1
                               / \
                              H0  I0

           3) Walk the tree and spit out "Argument" commands to tell
           the server which directories to munge.

           Yuck.  It's not clear this is worth spending time on, since
           we might want to disable cvs commands entirely from
           directories that do not have CVSADM files...

           Anyways, the solution as it stands has modified server.c
           (dirswitch) to create admin files [via server.c
           (create_adm_p)] in all path elements for a client's
           "Directory xxx" command, which forces the server to descend
           and serve the files there.  client.c (send_file_names) has
           also been modified to send only those arguments which are
           appropriate to current_parsed_root.

        */
                
        /* Construct a fake argc/argv pair. */
                
        int our_argc = 0, i;
        char **our_argv = NULL;

        if (! list_isempty (args_to_send_when_finished))
        {
            Node *head, *p;

            head = args_to_send_when_finished->list;

            /* count the number of nodes */
            i = 0;
            for (p = head->next; p != head; p = p->next)
                i++;
            our_argc = i;

            /* create the argument vector */
            our_argv = xmalloc (sizeof (char *) * our_argc);

            /* populate it */
            i = 0;
            for (p = head->next; p != head; p = p->next)
                our_argv[i++] = xstrdup (p->key);
        }

        /* We don't want to expand widcards, since we've just created
           a list of directories directly from the filesystem. */
        send_file_names (our_argc, our_argv, 0);

        /* Free our argc/argv. */
        if (our_argv != NULL)
        {
            for (i = 0; i < our_argc; i++)
                free (our_argv[i]);
            free (our_argv);
        }

        dellist (&args_to_send_when_finished);
    }
#endif

    return err;
}



/*
 * Implement the recursive policies on the local directory.  This may be
 * called directly, or may be called by start_recursion.
 */
static int
do_recursion (struct recursion_frame *frame)
{
    int err = 0;
    int dodoneproc = 1;
    char *srepository = NULL;
    List *entries = NULL;
    int locktype;
    bool process_this_directory = true;

#ifdef HAVE_PRINT_PTR
    TRACE (TRACE_FLOW, "do_recursion ( frame=%p )", (void *) frame);
#else
    TRACE (TRACE_FLOW, "do_recursion ( frame=%lx )", (unsigned long) frame);
#endif

    /* do nothing if told */
    if (frame->flags == R_SKIP_ALL)
        return 0;

    locktype = noexec ? CVS_LOCK_NONE : frame->locktype;

    /* The fact that locks are not active here is what makes us fail to have
       the

           If someone commits some changes in one cvs command,
           then an update by someone else will either get all the
           changes, or none of them.

       property (see node Concurrency in cvs.texinfo).

       The most straightforward fix would just to readlock the whole
       tree before starting an update, but that means that if a commit
       gets blocked on a big update, it might need to wait a *long*
       time.

       A more adequate fix would be a two-pass design for update,
       checkout, etc.  The first pass would go through the repository,
       with the whole tree readlocked, noting what versions of each
       file we want to get.  The second pass would release all locks
       (except perhaps short-term locks on one file at a
       time--although I think RCS already deals with this) and
       actually get the files, specifying the particular versions it wants.

       This could be sped up by separating out the data needed for the
       first pass into a separate file(s)--for example a file
       attribute for each file whose value contains the head revision
       for each branch.  The structure should be designed so that
       commit can relatively quickly update the information for a
       single file or a handful of files (file attributes, as
       implemented in Jan 96, are probably acceptable; improvements
       would be possible such as branch attributes which are in
       separate files for each branch).  */

#if defined(SERVER_SUPPORT) && defined(SERVER_FLOWCONTROL)
    /*
     * Now would be a good time to check to see if we need to stop
     * generating data, to give the buffers a chance to drain to the
     * remote client.  We should not have locks active at this point,
     * but if there are writelocks around, we cannot pause here.  */
    if (server_active && locktype != CVS_LOCK_WRITE)
        server_pause_check();
#endif

    /* Check the value in CVSADM_ROOT and see if it's in the list.  If
       not, add it to our lists of CVS/Root directories and do not
       process the files in this directory.  Otherwise, continue as
       usual.  THIS_ROOT might be NULL if we're doing an initial
       checkout -- check before using it.  The default should be that
       we process a directory's contents and only skip those contents
       if a CVS/Root file exists.

       If we're running the server, we want to process all
       directories, since we're guaranteed to have only one CVSROOT --
       our own.  */

    if (
        /* If -d was specified, it should override CVS/Root.

           In the single-repository case, it is long-standing CVS behavior
           and makes sense - the user might want another access method,
           another server (which mounts the same repository), &c.

           In the multiple-repository case, -d overrides all CVS/Root
           files.  That is the only plausible generalization I can
           think of.  */
        CVSroot_cmdline == NULL

#ifdef SERVER_SUPPORT
        && ! server_active
#endif
        )
    {
        cvsroot_t *this_root = Name_Root (NULL, update_dir);
        if (this_root != NULL)
        {
            if (findnode (root_directories, this_root->original))
            {
                process_this_directory =
                    !strcmp (original_parsed_root->original,
                             this_root->original);
            }
            else
            {
                /* Add it to our list. */

                Node *n = getnode ();
                n->type = NT_UNKNOWN;
                n->key = xstrdup (this_root->original);
                n->data = this_root;

                if (addnode (root_directories, n))
                    error (1, 0, "cannot add new CVSROOT %s",
                           this_root->original);

                process_this_directory = false;
            }
        }
    }

    /*
     * Fill in repository with the current repository
     */
    if (frame->which & W_LOCAL)
    {
        if (isdir (CVSADM))
        {
            repository = Name_Repository (NULL, update_dir);
            srepository = repository;           /* remember what to free */
        }
        else
            repository = NULL;
    }
    else
    {
        repository = frame->repository;
        assert (repository != NULL);
        assert (strstr (repository, "/./") == NULL);
    }

    fileattr_startdir (repository);

    /*
     * The filesdoneproc needs to be called for each directory where files
     * processed, or each directory that is processed by a call where no
     * directories were passed in.  In fact, the only time we don't want to
     * call back the filesdoneproc is when we are processing directories that
     * were passed in on the command line (or in the special case of `.' when
     * we were called with no args
     */
    if (dirlist != NULL && filelist == NULL)
        dodoneproc = 0;

    /*
     * If filelist or dirlist is already set, we don't look again. Otherwise,
     * find the files and directories
     */
    if (filelist == NULL && dirlist == NULL)
    {
        /* both lists were NULL, so start from scratch */
        if (frame->fileproc != NULL && frame->flags != R_SKIP_FILES)
        {
            int lwhich = frame->which;

            /* be sure to look in the attic if we have sticky tags/date */
            if ((lwhich & W_ATTIC) == 0)
                if (isreadable (CVSADM_TAG))
                    lwhich |= W_ATTIC;

            /* In the !(which & W_LOCAL) case, we filled in repository
               earlier in the function.  In the (which & W_LOCAL) case,
               the Find_Names function is going to look through the
               Entries file.  If we do not have a repository, that
               does not make sense, so we insist upon having a
               repository at this point.  Name_Repository will give a
               reasonable error message.  */
            if (repository == NULL)
            {
                Name_Repository (NULL, update_dir);
                assert (!"Not reached.  Please report this problem to <bug-cvs@gnu.org>");
            }
            /* find the files and fill in entries if appropriate */
            if (process_this_directory)
            {
                filelist = Find_Names (repository, lwhich, frame->aflag,
                                       &entries);
                if (filelist == NULL)
                {
                    error (0, 0, "skipping directory %s", update_dir);
                    /* Note that Find_Directories and the filesdoneproc
                       in particular would do bad things ("? foo.c" in
                       the case of some filesdoneproc's).  */
                    goto skip_directory;
                }
            }
        }

        /* find sub-directories if we will recurse */
        if (frame->flags != R_SKIP_DIRS)
            dirlist = Find_Directories (
                process_this_directory ? repository : NULL,
                frame->which, entries);
    }
    else
    {
        /* something was passed on the command line */
        if (filelist != NULL && frame->fileproc != NULL)
        {
            /* we will process files, so pre-parse entries */
            if (frame->which & W_LOCAL)
                entries = Entries_Open (frame->aflag, NULL);
        }
    }

    /* process the files (if any) */
    if (process_this_directory && filelist != NULL && frame->fileproc)
    {
        struct file_info finfo_struct;
        struct frame_and_file frfile;

        /* Lock the repository, if necessary. */
        if (repository)
        {
            if (locktype == CVS_LOCK_READ)
            {
                if (Reader_Lock (repository) != 0)
                    error (1, 0, "read lock failed - giving up");
            }
            else if (locktype == CVS_LOCK_WRITE)
                lock_dir_for_write (repository);
        }

#ifdef CLIENT_SUPPORT
        /* For the server, we handle notifications in a completely different
           place (server_notify).  For local, we can't do them here--we don't
           have writelocks in place, and there is no way to get writelocks
           here.  */
        if (current_parsed_root->isremote)
            notify_check (repository, update_dir);
#endif /* CLIENT_SUPPORT */

        finfo_struct.repository = repository;
        finfo_struct.update_dir = update_dir;
        finfo_struct.entries = entries;
        /* do_file_proc will fill in finfo_struct.file.  */

        frfile.finfo = &finfo_struct;
        frfile.frame = frame;

        /* process the files */
        err += walklist (filelist, do_file_proc, &frfile);

        /* unlock it */
        if (/* We only lock the repository above when repository is set */
            repository
            /* and when asked for a read or write lock. */
            && locktype != CVS_LOCK_NONE)
            Simple_Lock_Cleanup ();

        /* clean up */
        dellist (&filelist);
    }

    /* call-back files done proc (if any) */
    if (process_this_directory && dodoneproc && frame->filesdoneproc != NULL)
        err = frame->filesdoneproc (frame->callerdat, err, repository,
                                    update_dir[0] ? update_dir : ".",
                                    entries);

 skip_directory:
    fileattr_write ();
    fileattr_free ();

    /* process the directories (if necessary) */
    if (dirlist != NULL)
    {
        struct frame_and_entries frent;

        frent.frame = frame;
        frent.entries = entries;
        err += walklist (dirlist, do_dir_proc, &frent);
    }
#if 0
    else if (frame->dirleaveproc != NULL)
        err += frame->dirleaveproc (frame->callerdat, ".", err, ".");
#endif
    dellist (&dirlist);

    if (entries)
    {
        Entries_Close (entries);
        entries = NULL;
    }

    /* free the saved copy of the pointer if necessary */
    if (srepository)
        free (srepository);
    repository = NULL;

#ifdef HAVE_PRINT_PTR
    TRACE (TRACE_FLOW, "Leaving do_recursion (frame=%p)", (void *)frame);
#else
    TRACE (TRACE_FLOW, "Leaving do_recursion (frame=%lx)",
           (unsigned long)frame);
#endif

    return err;
}



/*
 * Process each of the files in the list with the callback proc
 *
 * NOTES
 *    Fills in FINFO->fullname, and sometimes FINFO->rcs before
 *    calling the callback proc (FRFILE->frame->fileproc), but frees them
 *    before return.
 *
 * OUTPUTS
 *    Fills in FINFO->file.
 *
 * RETURNS
 *    0 if we were supposed to find an RCS file but couldn't.
 *    Otherwise, returns the error code returned by the callback function.
 */
static int
do_file_proc (Node *p, void *closure)
{
    struct frame_and_file *frfile = closure;
    struct file_info *finfo = frfile->finfo;
    int ret;
    char *tmp;

    finfo->file = p->key;
    if (finfo->update_dir[0] != '\0')
        tmp = Xasprintf ("%s/%s", finfo->update_dir, finfo->file);
    else
        tmp = xstrdup (finfo->file);

    if (frfile->frame->dosrcs && repository)
    {
        finfo->rcs = RCS_parse (finfo->file, repository);

        /* OK, without W_LOCAL the error handling becomes relatively
           simple.  The file names came from readdir() on the
           repository and so we know any ENOENT is an error
           (e.g. symlink pointing to nothing).  Now, the logic could
           be simpler - since we got the name from readdir, we could
           just be calling RCS_parsercsfile.  */
        if (finfo->rcs == NULL
            && !(frfile->frame->which & W_LOCAL))
        {
            error (0, 0, "could not read RCS file for %s", tmp);
            free (tmp);
            cvs_flushout ();
            return 0;
        }
    }
    else
        finfo->rcs = NULL;
    finfo->fullname = tmp;
    ret = frfile->frame->fileproc (frfile->frame->callerdat, finfo);

    freercsnode (&finfo->rcs);
    free (tmp);

    /* Allow the user to monitor progress with tail -f.  Doing this once
       per file should be no big deal, but we don't want the performance
       hit of flushing on every line like previous versions of CVS.  */
    cvs_flushout ();

    return ret;
}



/*
 * Process each of the directories in the list (recursing as we go)
 */
static int
do_dir_proc (Node *p, void *closure)
{
    struct frame_and_entries *frent = (struct frame_and_entries *) closure;
    struct recursion_frame *frame = frent->frame;
    struct recursion_frame xframe;
    char *dir = p->key;
    char *newrepos;
    List *sdirlist;
    char *srepository;
    Dtype dir_return = R_PROCESS;
    int stripped_dot = 0;
    int err = 0;
    struct saved_cwd cwd;
    char *saved_update_dir;
    bool process_this_directory = true;

    if (fncmp (dir, CVSADM) == 0)
    {
        /* This seems to most often happen when users (beginning users,
           generally), try "cvs ci *" or something similar.  On that
           theory, it is possible that we should just silently skip the
           CVSADM directories, but on the other hand, using a wildcard
           like this isn't necessarily a practice to encourage (it operates
           only on files which exist in the working directory, unlike
           regular CVS recursion).  */

        /* FIXME-reentrancy: printed_cvs_msg should be in a "command
           struct" or some such, so that it gets cleared for each new
           command (this is possible using the remote protocol and a
           custom-written client).  The struct recursion_frame is not
           far back enough though, some commands (commit at least)
           will call start_recursion several times.  An alternate solution
           would be to take this whole check and move it to a new function
           validate_arguments or some such that all the commands call
           and which snips the offending directory from the argc,argv
           vector.  */
        static int printed_cvs_msg = 0;
        if (!printed_cvs_msg)
        {
            error (0, 0, "warning: directory %s specified in argument",
                   dir);
            error (0, 0, "\
but CVS uses %s for its own purposes; skipping %s directory",
                   CVSADM, dir);
            printed_cvs_msg = 1;
        }
        return 0;
    }

    saved_update_dir = update_dir;
    update_dir = xmalloc (strlen (saved_update_dir)
                          + strlen (dir)
                          + 5);
    strcpy (update_dir, saved_update_dir);

    /* set up update_dir - skip dots if not at start */
    if (strcmp (dir, ".") != 0)
    {
        if (update_dir[0] != '\0')
        {
            (void) strcat (update_dir, "/");
            (void) strcat (update_dir, dir);
        }
        else
            (void) strcpy (update_dir, dir);

        /*
         * Here we need a plausible repository name for the sub-directory. We
         * create one by concatenating the new directory name onto the
         * previous repository name.  The only case where the name should be
         * used is in the case where we are creating a new sub-directory for
         * update -d and in that case the generated name will be correct.
         */
        if (repository == NULL)
            newrepos = xstrdup ("");
        else
        {
            newrepos = xmalloc (strlen (repository) + strlen (dir) + 5);
            sprintf (newrepos, "%s/%s", repository, dir);
        }
    }
    else
    {
        if (update_dir[0] == '\0')
            (void) strcpy (update_dir, dir);

        if (repository == NULL)
            newrepos = xstrdup ("");
        else
            newrepos = xstrdup (repository);
    }

    /* Check to see that the CVSADM directory, if it exists, seems to be
       well-formed.  It can be missing files if the user hit ^C in the
       middle of a previous run.  We want to (a) make this a nonfatal
       error, and (b) make sure we print which directory has the
       problem.

       Do this before the direntproc, so that (1) the direntproc
       doesn't have to guess/deduce whether we will skip the directory
       (e.g. send_dirent_proc and whether to send the directory), and
       (2) so that the warm fuzzy doesn't get printed if we skip the
       directory.  */
    if (frame->which & W_LOCAL)
    {
        char *cvsadmdir;

        cvsadmdir = xmalloc (strlen (dir)
                             + sizeof (CVSADM_REP)
                             + sizeof (CVSADM_ENT)
                             + 80);

        strcpy (cvsadmdir, dir);
        strcat (cvsadmdir, "/");
        strcat (cvsadmdir, CVSADM);
        if (isdir (cvsadmdir))
        {
            strcpy (cvsadmdir, dir);
            strcat (cvsadmdir, "/");
            strcat (cvsadmdir, CVSADM_REP);
            if (!isfile (cvsadmdir))
            {
                /* Some commands like update may have printed "? foo" but
                   if we were planning to recurse, and don't on account of
                   CVS/Repository, we want to say why.  */
                error (0, 0, "ignoring %s (%s missing)", update_dir,
                       CVSADM_REP);
                dir_return = R_SKIP_ALL;
            }

            /* Likewise for CVS/Entries.  */
            if (dir_return != R_SKIP_ALL)
            {
                strcpy (cvsadmdir, dir);
                strcat (cvsadmdir, "/");
                strcat (cvsadmdir, CVSADM_ENT);
                if (!isfile (cvsadmdir))
                {
                    /* Some commands like update may have printed "? foo" but
                       if we were planning to recurse, and don't on account of
                       CVS/Repository, we want to say why.  */
                    error (0, 0, "ignoring %s (%s missing)", update_dir,
                           CVSADM_ENT);
                    dir_return = R_SKIP_ALL;
                }
            }
        }
        free (cvsadmdir);
    }

    /* Only process this directory if the root matches.  This nearly
       duplicates code in do_recursion. */

    if (
        /* If -d was specified, it should override CVS/Root.

           In the single-repository case, it is long-standing CVS behavior
           and makes sense - the user might want another access method,
           another server (which mounts the same repository), &c.

           In the multiple-repository case, -d overrides all CVS/Root
           files.  That is the only plausible generalization I can
           think of.  */
        CVSroot_cmdline == NULL

#ifdef SERVER_SUPPORT
        && ! server_active
#endif
        )
    {
        cvsroot_t *this_root = Name_Root (dir, update_dir);
        if (this_root != NULL)
        {
            if (findnode (root_directories, this_root->original))
            {
                process_this_directory =
                    !strcmp (original_parsed_root->original,
                             this_root->original);
            }
            else
            {
                /* Add it to our list. */

                Node *n = getnode ();
                n->type = NT_UNKNOWN;
                n->key = xstrdup (this_root->original);
                n->data = this_root;

                if (addnode (root_directories, n))
                    error (1, 0, "cannot add new CVSROOT %s",
                           this_root->original);

                process_this_directory = false;
            }
        }
    }

    /* call-back dir entry proc (if any) */
    if (dir_return == R_SKIP_ALL)
        ;
    else if (frame->direntproc != NULL)
    {
        /* If we're doing the actual processing, call direntproc.
           Otherwise, assume that we need to process this directory
           and recurse. FIXME. */

        if (process_this_directory)
            dir_return = frame->direntproc (frame->callerdat, dir, newrepos,
                                            update_dir, frent->entries);
        else
            dir_return = R_PROCESS;
    }
    else
    {
        /* Generic behavior.  I don't see a reason to make the caller specify
           a direntproc just to get this.  */
        if ((frame->which & W_LOCAL) && !isdir (dir))
            dir_return = R_SKIP_ALL;
    }

    free (newrepos);

    /* only process the dir if the return code was 0 */
    if (dir_return != R_SKIP_ALL)
    {
        /* save our current directory and static vars */
        if (save_cwd (&cwd))
            error (1, errno, "Failed to save current directory.");
        sdirlist = dirlist;
        srepository = repository;
        dirlist = NULL;

        /* cd to the sub-directory */
        if (CVS_CHDIR (dir) < 0)
            error (1, errno, "could not chdir to %s", dir);

        /* honor the global SKIP_DIRS (a.k.a. local) */
        if (frame->flags == R_SKIP_DIRS)
            dir_return = R_SKIP_DIRS;

        /* remember if the `.' will be stripped for subsequent dirs */
        if (strcmp (update_dir, ".") == 0)
        {
            update_dir[0] = '\0';
            stripped_dot = 1;
        }

        /* make the recursive call */
        xframe = *frame;
        xframe.flags = dir_return;
        /* Keep track of repository, really just for r* commands (rtag, rdiff,
         * co, ...) to tag_check_valid, since all the other commands use
         * CVS/Repository to figure it out per directory.
         */
        if (repository)
        {
            if (strcmp (dir, ".") == 0)
                xframe.repository = xstrdup (repository);
            else
            {
                xframe.repository = xmalloc (strlen (repository)
                                             + strlen (dir)
                                             + 2);
                sprintf (xframe.repository, "%s/%s", repository, dir);
            }
        }
        else
            xframe.repository = NULL;
        err += do_recursion (&xframe);
        if (xframe.repository)
        {
            free (xframe.repository);
            xframe.repository = NULL;
        }

        /* put the `.' back if necessary */
        if (stripped_dot)
            (void) strcpy (update_dir, ".");

        /* call-back dir leave proc (if any) */
        if (process_this_directory && frame->dirleaveproc != NULL)
            err = frame->dirleaveproc (frame->callerdat, dir, err, update_dir,
                                       frent->entries);

        /* get back to where we started and restore state vars */
        if (restore_cwd (&cwd))
            error (1, errno, "Failed to restore current directory, `%s'.",
                   cwd.name);
        free_cwd (&cwd);
        dirlist = sdirlist;
        repository = srepository;
    }

    free (update_dir);
    update_dir = saved_update_dir;

    return err;
}

/*
 * Add a node to a list allocating the list if necessary.
 */
static void
addlist (List **listp, char *key)
{
    Node *p;

    if (*listp == NULL)
        *listp = getlist ();
    p = getnode ();
    p->type = FILES;
    p->key = xstrdup (key);
    if (addnode (*listp, p) != 0)
        freenode (p);
}

static void
addfile (List **listp, char *dir, char *file)
{
    Node *n;
    List *fl;

    /* add this dir. */
    addlist (listp, dir);

    n = findnode (*listp, dir);
    if (n == NULL)
    {
        error (1, 0, "can't find recently added dir node `%s' in start_recursion.",
               dir);
    }

    n->type = DIRS;
    fl = n->data;
    addlist (&fl, file);
    n->data = fl;
    return;
}

static int
unroll_files_proc (Node *p, void *closure)
{
    Node *n;
    struct recursion_frame *frame = (struct recursion_frame *) closure;
    int err = 0;
    List *save_dirlist;
    char *save_update_dir = NULL;
    struct saved_cwd cwd;

    /* if this dir was also an explicitly named argument, then skip
       it.  We'll catch it later when we do dirs. */
    n = findnode (dirlist, p->key);
    if (n != NULL)
        return (0);

    /* otherwise, call dorecusion for this list of files. */
    filelist = p->data;
    p->data = NULL;
    save_dirlist = dirlist;
    dirlist = NULL;

    if (strcmp(p->key, ".") != 0)
    {
        if (save_cwd (&cwd))
            error (1, errno, "Failed to save current directory.");
        if ( CVS_CHDIR (p->key) < 0)
            error (1, errno, "could not chdir to %s", p->key);

        save_update_dir = update_dir;
        update_dir = xmalloc (strlen (save_update_dir)
                                  + strlen (p->key)
                                  + 5);
        strcpy (update_dir, save_update_dir);

        if (*update_dir != '\0')
            (void) strcat (update_dir, "/");

        (void) strcat (update_dir, p->key);
    }

    err += do_recursion (frame);

    if (save_update_dir != NULL)
    {
        free (update_dir);
        update_dir = save_update_dir;

        if (restore_cwd (&cwd))
            error (1, errno, "Failed to restore current directory, `%s'.",
                   cwd.name);
        free_cwd (&cwd);
    }

    dirlist = save_dirlist;
    if (filelist)
        dellist (&filelist);
    return(err);
}
/* vim:tabstop=8:shiftwidth=4
 */