X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=uid.c;h=d069d7d0484b5b2bdeb1c01170fd5187762d537b;hb=f16d8d23439b5569f0c2e1af22494708b507f277;hp=000c02330f3e38abe5fcc7fd6aae1c12d8dfc8c6;hpb=4cb267590512956e78cc054f816fc6294088ce2b;p=~andy%2Ffetchmail

diff --git a/uid.c b/uid.c
index 000c0233..d069d7d0 100644
--- a/uid.c
+++ b/uid.c
@@ -1,27 +1,12 @@
-/*
- * uid.c -- UIDL handling for POP3 servers without LAST
+/**
+ * \file uid.c
+ * UID list handling (currently, only for POP3)
  *
  * For license terms, see the file COPYING in this directory.
- */
-
-#include "config.h"
-
-#include <stdio.h>
-#if defined(STDC_HEADERS)
-#include <stdlib.h>
-#include <string.h>
-#endif
-#if defined(HAVE_UNISTD_H)
-#include <unistd.h>
-#endif
-
-#include "fetchmail.h"
-
-/*
- * Machinery for handling UID lists live here.  This is mainly to support
- * RFC1725-conformant POP3 servers without a LAST command, but may also be
- * useful for making the IMAP4 querying logic UID-oriented, if a future
- * revision of IMAP forces me to.
+ *
+ * Machinery for handling UID lists live here.  This is currently used
+ * by POP3, but may also be useful for making the IMAP4 querying logic
+ * UID-oriented.
  *
  * These functions are also used by the rest of the code to maintain
  * string lists.
@@ -32,21 +17,21 @@
  * considered seen in `oldsaved'.  These are messages that were left in
  * the mailbox and *not deleted* on previous queries (we don't need to
  * remember the UIDs of deleted messages because ... well, they're gone!)
- * This list is initially set up by initialized_saved_list() from the
+ * This list is initially set up by initialize_saved_list() from the
  * .fetchids file.
  *
- * Early in the query, during the execution of the protocol-specific 
+ * Early in the query, during the execution of the protocol-specific
  * getrange code, the driver expects that the host's `newsaved' member
  * will be filled with a list of UIDs and message numbers representing
  * the mailbox state.  If this list is empty, the server did
  * not respond to the request for a UID listing.
  *
  * Each time a message is fetched, we can check its UID against the
- * `oldsaved' list to see if it is old.  If not, it should be downloaded
- * (and possibly deleted).  It should be downloaded anyway if --all
- * is on.  It should not be deleted if --keep is on.
+ * `oldsaved' list to see if it is old.
+ *
+ * Each time a message-id is seen, we mark it with MARK_SEEN.
  *
- * Each time a message is deleted, we mark its id UID_DELETED from the
+ * Each time a message is deleted, we mark its id UID_DELETED in the
  * `newsaved' member.  When we want to assert that an expunge has been
  * done on the server, we call expunge_uid() to register that all
  * deleted messages are gone by marking them UID_EXPUNGED.
@@ -54,280 +39,480 @@
  * At the end of the query, the `newsaved' member becomes the
  * `oldsaved' list.  The old `oldsaved' list is freed.
  *
- * At the end of the fetchmail run, non-EXPUNGED members of all
+ * At the end of the fetchmail run, seen and non-EXPUNGED members of all
  * current `oldsaved' lists are flushed out to the .fetchids file to
- * be picked up by the next run.  (The UID_EXPUNGED test means that a
- * message marked UID_DELETED may still have its ID go to disk if
- * there has been no intervening expunge operation.  This typically
- * comes up if the query was aborted by a line hit before a quit or
- * expunge was sent to the server.)  If there are no un-expunged
+ * be picked up by the next run.  If there are no un-expunged
  * messages, the file is deleted.
  *
- * Note: all comparisons are caseblind!
+ * One disadvantage of UIDL is that all the UIDs have to be downloaded
+ * before a search for new messages can be done. Typically, new messages
+ * are appended to mailboxes. Hence, downloading all UIDs just to download
+ * a few new mails is a waste of bandwidth. If new messages are always at
+ * the end of the mailbox, fast UIDL will decrease the time required to
+ * download new mails.
+ *
+ * During fast UIDL, the UIDs of all messages are not downloaded! The first
+ * unseen message is searched for by using a binary search on UIDs. UIDs
+ * after the first unseen message are downloaded as and when needed.
+ *
+ * The advantages of fast UIDL are (this is noticeable only when the
+ * mailbox has too many mails):
+ *
+ * - There is no need to download the UIDs of all mails right at the start.
+ * - There is no need to save all the UIDs in memory separately in
+ * `newsaved' list.
+ * - There is no need to download the UIDs of seen mail (except for the
+ * first binary search).
+ * - The first new mail is downloaded considerably faster.
+ *
+ * The disadvantages are:
+ *
+ * - Since all UIDs are not downloaded, it is not possible to swap old and
+ * new list. The current state of the mailbox is essentially a merged state
+ * of old and new mails.
+ * - If an intermediate mail has been temporarily refused (say, due to 4xx
+ * code from the smtp server), this mail may not get downloaded.
+ * - If 'flush' is used, such intermediate mails will also get deleted.
+ *
+ * The first two disadvantages can be overcome by doing a linear search
+ * once in a while (say, every 10th poll). Also, with flush, fast UIDL
+ * should be disabled.
+ *
+ * Note: some comparisons (those used for DNS address lists) are caseblind!
  */
 
-/* UIDs associated with un-queried hosts */
-static struct idlist *scratchlist;
+#include "config.h"
+
+#include <sys/stat.h>
+#include <errno.h>
+#include <stdio.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "fetchmail.h"
+#include "gettext.h"
+#include "sdump.h"
+
+int dofastuidl = 0;
 
 #ifdef POP3_ENABLE
+/** UIDs associated with un-queried hosts */
+static struct idlist *scratchlist;
+
+static int dump_saved_uid(struct uid_db_record *rec, void *unused)
+{
+    char *t;
+
+    (void)unused;
+
+    t = sdump(rec->id, rec->id_len);
+    report_build(stdout, " %s", t);
+    free(t);
+
+    return 0;
+}
+
+/** Read saved IDs from \a idfile and attach to each host in \a hostlist. */
 void initialize_saved_lists(struct query *hostlist, const char *idfile)
-/* read file of saved IDs and attach to each host */
 {
-    int	st;
+    struct stat statbuf;
     FILE	*tmpfp;
     struct query *ctl;
 
     /* make sure lists are initially empty */
-    for (ctl = hostlist; ctl; ctl = ctl->next)
-	ctl->oldsaved = ctl->newsaved = (struct idlist *)NULL;
+    for (ctl = hostlist; ctl; ctl = ctl->next) {
+	ctl->skipped = (struct idlist *)NULL;
+
+	init_uid_db(&ctl->oldsaved);
+	init_uid_db(&ctl->newsaved);
+    }
+
+    errno = 0;
+
+    /*
+     * Croak if the uidl directory does not exist.
+     * This probably means an NFS mount failed and we can't
+     * see a uidl file that ought to be there.
+     * Question: is this a portable check? It's not clear
+     * that all implementations of lstat() will return ENOTDIR
+     * rather than plain ENOENT in this case...
+     */
+    if (lstat(idfile, &statbuf) < 0) {
+	if (errno == ENOTDIR)
+	{
+	    report(stderr, "lstat: %s: %s\n", idfile, strerror(errno));
+	    exit(PS_IOERR);
+	}
+    }
 
     /* let's get stored message UIDs from previous queries */
-    if ((tmpfp = fopen(idfile, "r")) != (FILE *)NULL) {
-	char buf[POPBUFSIZE+1],host[HOSTLEN+1],user[USERNAMELEN+1],id[IDLEN+1];
+    if ((tmpfp = fopen(idfile, "r")) != (FILE *)NULL)
+    {
+	char buf[POPBUFSIZE+1];
+	char *host = NULL;	/* pacify -Wall */
+	char *user;
+	char *id;
+	char *atsign;	/* temp pointer used in parsing user and host */
+	char *delimp1;
+	char saveddelim1;
+	char *delimp2;
+	char saveddelim2 = '\0';	/* pacify -Wall */
 
 	while (fgets(buf, POPBUFSIZE, tmpfp) != (char *)NULL)
 	{
-	    /* possible lossage here with very old versions of sscanf(3)... */
-	    if ((st = sscanf(buf, "%[^@]@%s %s\n", user, host, id)) == 3)
+	    /*
+	     * At this point, we assume the bug has two fields -- a user@host
+	     * part, and an ID part. Either field may contain spurious @ signs.
+	     * The previous version of this code presumed one could split at
+	     * the rightmost '@'.  This is not correct, as InterMail puts an
+	     * '@' in the UIDL.
+	     */
+
+	    /* first, skip leading spaces */
+	    user = buf + strspn(buf, " \t");
+
+	    /*
+	     * First, we split the buf into a userhost part and an id
+	     * part ... but id doesn't necessarily start with a '<',
+	     * espescially if the POP server returns an X-UIDL header
+	     * instead of a Message-ID, as GMX's (www.gmx.net) POP3
+	     * StreamProxy V1.0 does.
+	     *
+	     * this is one other trick. The userhost part
+	     * may contain ' ' in the user part, at least in
+	     * the lotus notes case.
+	     * So we start looking for the '@' after which the
+	     * host will follow with the ' ' separator with the id.
+	     *
+	     * XXX FIXME: There is a case this code cannot handle:
+	     * the user name cannot have blanks after a '@'.
+	     */
+	    if ((delimp1 = strchr(user, '@')) != NULL &&
+		(id = strchr(delimp1,' ')) != NULL)
 	    {
-		for (ctl = hostlist; ctl; ctl = ctl->next)
-		{
-		    if (ctl->server.truename &&
-		        strcasecmp(host, ctl->server.truename) == 0
-				&& strcasecmp(user, ctl->remotename) == 0)
-		    {
-			save_str(&ctl->oldsaved, UID_KEPT, id);
+	        for (delimp1 = id; delimp1 >= user; delimp1--)
+		    if ((*delimp1 != ' ') && (*delimp1 != '\t'))
 			break;
-		    }
+
+		/*
+		 * It should be safe to assume that id starts after
+		 * the " " - after all, we're writing the " "
+		 * ourselves in write_saved_lists() :-)
+		 */
+		id = id + strspn(id, " ");
+
+		delimp1++; /* but what if there is only white space ?!? */
+		/* we have at least one @, else we are not in this branch */
+		saveddelim1 = *delimp1;		/* save char after token */
+		*delimp1 = '\0';		/* delimit token with \0 */
+
+		/* now remove trailing white space chars from id */
+		if ((delimp2 = strpbrk(id, " \t\n")) != NULL ) {
+		    saveddelim2 = *delimp2;
+		    *delimp2 = '\0';
 		}
 
-		/* if it's not in a host we're querying, save it anyway */
-		if (ctl == (struct query *)NULL)
-		    save_str(&scratchlist, UID_KEPT, buf);
+		atsign = strrchr(user, '@');
+		/* we have at least one @, else we are not in this branch */
+		*atsign = '\0';
+		host = atsign + 1;
+
+		/* find uidl db and save it */
+		for (ctl = hostlist; ctl; ctl = ctl->next) {
+		    if (strcasecmp(host, ctl->server.queryname) == 0
+			    && strcasecmp(user, ctl->remotename) == 0) {
+			uid_db_insert(&ctl->oldsaved, id, UID_SEEN);
+			break;
+		    }
+		}
+		/*
+		 * If it's not in a host we're querying,
+		 * save it anyway.  Otherwise we'd lose UIDL
+		 * information any time we queried an explicit
+		 * subset of hosts.
+		 */
+		if (ctl == (struct query *)NULL) {
+		    /* restore string */
+		    *delimp1 = saveddelim1;
+		    *atsign = '@';
+		    if (delimp2 != NULL) {
+			*delimp2 = saveddelim2;
+		    }
+		    save_str(&scratchlist, buf, UID_SEEN);
+		}
 	    }
 	}
-	fclose(tmpfp);
+	fclose(tmpfp);	/* not checking should be safe, mode was "r" */
     }
-}
-#endif /* POP3_ENABLE */
 
-struct idlist *save_str(struct idlist **idl, int num, const char *str)
-/* save a number/UID pair on the given UID list */
-{
-    struct idlist **end;
+    if (outlevel >= O_DEBUG)
+    {
+	struct idlist	*idp;
 
-    /* do it nonrecursively so the list is in the right order */
-    for (end = idl; *end; end = &(*end)->next)
-	continue;
+	for (ctl = hostlist; ctl; ctl = ctl->next)
+	    {
+		report_build(stdout, GT_("Old UID list from %s:"),
+			     ctl->server.pollname);
+
+		if (!uid_db_n_records(&ctl->oldsaved))
+		    report_build(stdout, GT_(" <empty>"));
+		else
+		    traverse_uid_db(&ctl->oldsaved, dump_saved_uid, NULL);
 
-    *end = (struct idlist *)xmalloc(sizeof(struct idlist));
-    (*end)->val.num = num;
-    (*end)->id = str ? xstrdup(str) : (char *)NULL;
-    (*end)->next = NULL;
+		report_complete(stdout, "\n");
+	    }
 
-    return(*end);
+	report_build(stdout, GT_("Scratch list of UIDs:"));
+	if (!scratchlist)
+		report_build(stdout, GT_(" <empty>"));
+	else for (idp = scratchlist; idp; idp = idp->next) {
+		char *t = sdump(idp->id, strlen(idp->id)-1);
+		report_build(stdout, " %s\n", t);
+		free(t);
+	}
+	report_complete(stdout, "\n");
+    }
 }
 
-void free_str_list(struct idlist **idl)
-/* free the given UID list */
+static int mark_as_expunged_if(struct uid_db_record *rec, void *unused)
 {
-    if (*idl == (struct idlist *)NULL)
-	return;
+    (void)unused;
 
-    free_str_list(&(*idl)->next);
-    free ((*idl)->id);
-    free(*idl);
-    *idl = (struct idlist *)NULL;
+    if (rec->status == UID_DELETED) rec->status = UID_EXPUNGED;
+    return 0;
 }
 
-void save_str_pair(struct idlist **idl, const char *str1, const char *str2)
-/* save an ID pair on the given list */
+/** Assert that all UIDs marked deleted in query \a ctl have actually been
+expunged. */
+void expunge_uids(struct query *ctl)
 {
-    struct idlist **end;
-
-    /* do it nonrecursively so the list is in the right order */
-    for (end = idl; *end; end = &(*end)->next)
-	continue;
-
-    *end = (struct idlist *)xmalloc(sizeof(struct idlist));
-    (*end)->id = str1 ? xstrdup(str1) : (char *)NULL;
-    if (str2)
-	(*end)->val.id2 = xstrdup(str2);
-    else
-	(*end)->val.id2 = (char *)NULL;
-    (*end)->next = (struct idlist *)NULL;
+    traverse_uid_db(dofastuidl ? &ctl->oldsaved : &ctl->newsaved,
+		     mark_as_expunged_if, NULL);
 }
 
-#ifdef __UNUSED__
-void free_str_pair_list(struct idlist **idl)
-/* free the given ID pair list */
+static const char *str_uidmark(int mark)
 {
-    if (*idl == (struct idlist *)NULL)
-	return;
-
-    free_idpair_list(&(*idl)->next);
-    free ((*idl)->id);
-    free ((*idl)->val.id2);
-    free(*idl);
-    *idl = (struct idlist *)NULL;
+	static char buf[20];
+
+	switch(mark) {
+		case UID_UNSEEN:
+			return "UNSEEN";
+		case UID_SEEN:
+			return "SEEN";
+		case UID_EXPUNGED:
+			return "EXPUNGED";
+		case UID_DELETED:
+			return "DELETED";
+		default:
+			if (snprintf(buf, sizeof(buf), "MARK=%d", mark) < 0)
+				return "ERROR";
+			else
+				return buf;
+	}
 }
-#endif
 
-int str_in_list(struct idlist **idl, const char *str)
-/* is a given ID in the given list? (comparison is caseblind) */
+static int dump_uid_db_record(struct uid_db_record *rec, void *arg)
 {
-    if (*idl == (struct idlist *)NULL || str == (char *) NULL)
-	return(0);
-    else if (strcasecmp(str, (*idl)->id) == 0)
-	return(1);
-    else
-	return(str_in_list(&(*idl)->next, str));
-}
+	unsigned *n_recs;
+	char *t;
 
-int str_nr_in_list( struct idlist **idl, const char *str )
-  /* return the position of str in idl */
-{
-    int nr;
-    struct idlist *walk;
-    if ( !str )
-        return -1;
-    for( walk = *idl, nr = 0; walk; nr ++, walk = walk->next )
-        if( strcasecmp( str, walk->id) == 0 )
-	    return nr;
-    return -1;
-}
+	n_recs = (unsigned int *)arg;
+	--*n_recs;
 
-int count_list( struct idlist **idl )
-  /* count the number of elements in the list */
-{
-  if( !*idl )
-    return 0;
-  return 1 + count_list( &(*idl)->next );
-}
+	t = sdump(rec->id, rec->id_len);
+	report_build(stdout, " %s = %s%s", t, str_uidmark(rec->status), *n_recs ? "," : "");
+	free(t);
 
-char* str_from_nr_list( struct idlist **idl, int number )
-  /* return the number'th string in idl */
-{
-    if( !*idl  || number < 0)
-        return 0;
-    if( number == 0 )
-        return (*idl)->id;
-    return str_from_nr_list(&(*idl)->next, number-1);
+	return 0;
 }
 
-    
-char *str_find(struct idlist **idl, int number)
-/* return the id of the given number in the given list. */
+static void dump_uid_db(struct uid_db *db)
 {
-    if (*idl == (struct idlist *) 0)
-	return((char *) 0);
-    else if (number == (*idl)->val.num)
-	return((*idl)->id);
-    else
-	return(str_find(&(*idl)->next, number));
+	unsigned n_recs;
+
+	n_recs = uid_db_n_records(db);
+	if (!n_recs) {
+		report_build(stdout, GT_(" <empty>"));
+		return;
+	}
+
+	traverse_uid_db(db, dump_uid_db_record, &n_recs);
 }
 
-char *idpair_find(struct idlist **idl, const char *id)
-/* return the id of the given id in the given list (caseblind comparison) */
+/** Finish a successful query */
+void uid_swap_lists(struct query *ctl)
 {
-    if (*idl == (struct idlist *) 0)
-	return((char *) 0);
-    else if (strcasecmp(id, (*idl)->id) == 0)
-	return((*idl)->val.id2 ? (*idl)->val.id2 : (*idl)->id);
-    else
-	return(idpair_find(&(*idl)->next, id));
+    /* debugging code */
+    if (outlevel >= O_DEBUG)
+    {
+	if (dofastuidl) {
+	    report_build(stdout, GT_("Merged UID list from %s:"), ctl->server.pollname);
+	    dump_uid_db(&ctl->oldsaved);
+	} else {
+	    report_build(stdout, GT_("New UID list from %s:"), ctl->server.pollname);
+	    dump_uid_db(&ctl->newsaved);
+	}
+	report_complete(stdout, "\n");
+    }
+
+    /*
+     * Don't swap UID lists unless we've actually seen UIDLs.
+     * This is necessary in order to keep UIDL information
+     * from being heedlessly deleted later on.
+     *
+     * Older versions of fetchmail did
+     *
+     *     free_str_list(&scratchlist);
+     *
+     * after swap.  This was wrong; we need to preserve the UIDL information
+     * from unqueried hosts.  Unfortunately, not doing this means that
+     * under some circumstances UIDLs can end up being stored forever --
+     * specifically, if a user description is removed from .fetchmailrc
+     * with UIDLs from that account in .fetchids, there is no way for
+     * them to ever get garbage-collected.
+     */
+    if (uid_db_n_records(&ctl->newsaved))
+    {
+	swap_uid_db_data(&ctl->newsaved, &ctl->oldsaved);
+	clear_uid_db(&ctl->newsaved);
+    }
+    /* in fast uidl, there is no need to swap lists: the old state of
+     * mailbox cannot be discarded! */
+    else if (outlevel >= O_DEBUG && !dofastuidl)
+	report(stdout, GT_("not swapping UID lists, no UIDs seen this query\n"));
 }
 
-int delete_str(struct idlist **idl, int num)
-/* delete given message from given list */
+/** Finish a query which had errors */
+void uid_discard_new_list(struct query *ctl)
 {
-#ifdef HARD_DELETE	/* not used */
-    if (*idl == (struct idlist *)NULL)
-	return(0);
-    else if ((*idl)->val.num == num)
+    /* debugging code */
+    if (outlevel >= O_DEBUG)
     {
-	struct idlist	*next = (*idl)->next;
-
-	free ((*idl)->id);
-	free(*idl);
-	*idl = next;
-	return(1);
+	/* this is now a merged list! the mails which were seen in this
+	 * poll are marked here. */
+	report_build(stdout, GT_("Merged UID list from %s:"), ctl->server.pollname);
+	dump_uid_db(&ctl->oldsaved);
+	report_complete(stdout, "\n");
     }
-    else
-	return(delete_str(&(*idl)->next, num));
-#else
-    struct idlist	*idp;
 
-    for (idp = *idl; idp; idp = idp->next)
-	if (idp->val.num == num)
-	{
-	    idp->val.num = UID_DELETED;
-	    return(1);
-	}
-    return(0);
-#endif /* HARD_DELETE */
+    if (uid_db_n_records(&ctl->newsaved))
+    {
+	/* new state of mailbox is not reliable */
+	if (outlevel >= O_DEBUG)
+	    report(stdout, GT_("discarding new UID list\n"));
+	clear_uid_db(&ctl->newsaved);
+    }
 }
 
-void append_str_list(struct idlist **idl, struct idlist **nidl)
-/* append nidl to idl (does not copy *) */
+/** Reset the number associated with each id */
+void uid_reset_num(struct query *ctl)
 {
-    if ((*idl) == (struct idlist *)NULL)
-	*idl = *nidl;
-    else if ((*idl)->next == (struct idlist *)NULL)
-	(*idl)->next = *nidl;
-    else if ((*idl)->next != *nidl)
-	append_str_list(&(*idl)->next, nidl);
+    reset_uid_db_nums(&ctl->oldsaved);
 }
 
-#ifdef POP3_ENABLE
-void expunge_uids(struct query *ctl)
-/* assert that all UIDs marked deleted have actually been expunged */
+/** Write list of seen messages, at end of run. */
+static int count_seen_deleted(struct uid_db_record *rec, void *arg)
 {
-    struct idlist *idl;
-
-    for (idl = ctl->newsaved; idl; idl = idl->next)
-	if (idl->val.num == UID_DELETED)
-	    idl->val.num = UID_EXPUNGED;
+    if (rec->status == UID_SEEN || rec->status == UID_DELETED)
+	++*(long *)arg;
+    return 0;
 }
 
-void update_str_lists(struct query *ctl)
-/* perform end-of-query actions on UID lists */
+struct write_saved_info {
+    struct query *ctl;
+    FILE *fp;
+};
+
+static int write_uid_db_record(struct uid_db_record *rec, void *arg)
 {
-    free_str_list(&ctl->oldsaved);
-    ctl->oldsaved = ctl->newsaved;
-    ctl->newsaved = (struct idlist *) NULL;
+    struct write_saved_info *info;
+    int rc;
+
+    if (!(rec->status == UID_SEEN || rec->status == UID_DELETED))
+	return 0;
+
+    info = (struct write_saved_info *)arg;
+    rc = fprintf(info->fp, "%s@%s %s\n",
+		 info->ctl->remotename, info->ctl->server.queryname,
+		 rec->id);
+    return rc < 0 ? -1 : 0;
 }
 
+/** Write new list of UIDs (state) to \a idfile. */
 void write_saved_lists(struct query *hostlist, const char *idfile)
-/* perform end-of-run write of seen-messages list */
 {
-    int		idcount;
+    long	idcount;
     FILE	*tmpfp;
     struct query *ctl;
     struct idlist *idp;
 
     /* if all lists are empty, nuke the file */
     idcount = 0;
-    for (ctl = hostlist; ctl; ctl = ctl->next) {
-	if (ctl->oldsaved)
-	    idcount++;
-    }
+    for (ctl = hostlist; ctl; ctl = ctl->next)
+	traverse_uid_db(&ctl->oldsaved, count_seen_deleted, &idcount);
 
     /* either nuke the file or write updated last-seen IDs */
-    if (!idcount)
-	unlink(idfile);
-    else
-	if ((tmpfp = fopen(idfile, "w")) != (FILE *)NULL) {
+    if (!idcount && !scratchlist)
+    {
+	if (outlevel >= O_DEBUG) {
+	    if (access(idfile, F_OK) == 0)
+		    report(stdout, GT_("Deleting fetchids file.\n"));
+	}
+	if (unlink(idfile) && errno != ENOENT)
+	    report(stderr, GT_("Error deleting %s: %s\n"), idfile, strerror(errno));
+    } else {
+	char *newnam = (char *)xmalloc(strlen(idfile) + 2);
+	strcpy(newnam, idfile);
+	strcat(newnam, "_");
+	if (outlevel >= O_DEBUG)
+	    report(stdout, GT_("Writing fetchids file.\n"));
+	(void)unlink(newnam); /* remove file/link first */
+	if ((tmpfp = fopen(newnam, "w")) != (FILE *)NULL) {
+	    struct write_saved_info info;
+	    int errflg = 0;
+
+	    info.fp = tmpfp;
+
 	    for (ctl = hostlist; ctl; ctl = ctl->next) {
-		for (idp = ctl->oldsaved; idp; idp = idp->next)
-		    if (idp->val.num != UID_EXPUNGED)
-			fprintf(tmpfp, "%s@%s %s\n", 
-			    ctl->remotename, ctl->server.truename, idp->id);
+		info.ctl = ctl;
+
+		if (traverse_uid_db(&ctl->oldsaved, write_uid_db_record, &info) < 0) {
+		    int e = errno;
+		    report(stderr, GT_("Write error on fetchids file %s: %s\n"), newnam, strerror(e));
+		    errflg = 1;
+		    goto bailout;
+		}
 	    }
+
 	    for (idp = scratchlist; idp; idp = idp->next)
-		fputs(idp->id, tmpfp);
-	    fclose(tmpfp);
+		if (EOF == fputs(idp->id, tmpfp)) {
+			    int e = errno;
+			    report(stderr, GT_("Write error on fetchids file %s: %s\n"), newnam, strerror(e));
+			    errflg = 1;
+			    goto bailout;
+		}
+
+bailout:
+	    (void)fflush(tmpfp); /* return code ignored, we check ferror instead */
+	    errflg |= ferror(tmpfp);
+	    errflg |= fclose(tmpfp);
+	    /* if we could write successfully, move into place;
+	     * otherwise, drop */
+	    if (errflg) {
+		report(stderr, GT_("Error writing to fetchids file %s, old file left in place.\n"), newnam);
+		unlink(newnam);
+	    } else {
+		if (rename(newnam, idfile)) {
+		    report(stderr, GT_("Cannot rename fetchids file %s to %s: %s\n"), newnam, idfile, strerror(errno));
+		}
+	    }
+	} else {
+	    report(stderr, GT_("Cannot open fetchids file %s for writing: %s\n"), newnam, strerror(errno));
 	}
+	free(newnam);
+    }
 }
 #endif /* POP3_ENABLE */