Try to prevent .fetchids from being randomly nuked.

svn path=/trunk/; revision=2799

3 files changed, 25 insertions, 5 deletions

diff --git a/driver.c b/driver.c
index b10a1dd4..9c163d1d 100644
--- a/driver.c
+++ b/driver.c
@@ -1458,6 +1458,9 @@ const int maxfetch;		/* maximum number of messages to fetch */
     alrmsave = signal(SIGALRM, timeout_handler);
     mytimeout = ctl->server.timeout;
 
+    /* no UIDLs seen yet */
+    ctl->have_uids = TRUE;
+
     /* set up the broken-pipe timeout */
     pipesave = signal(SIGPIPE, sigpipe_handler);
 
@@ -1767,6 +1770,9 @@ const int maxfetch;		/* maximum number of messages to fetch */
 		if (ok != 0)
 		    goto cleanUp;
 
+		/* we've now seen any UIDs that will be coming up the link */
+		ctl->have_uids = TRUE;
+
 		/* show user how many messages we downloaded */
 		if (idp->id)
 		    (void) sprintf(buf, _("%s at %s (folder %s)"),
diff --git a/fetchmail.h b/fetchmail.h
index 76ec4a79..02cc3b9b 100644
--- a/fetchmail.h
+++ b/fetchmail.h
@@ -282,6 +282,7 @@ struct query
     unsigned int uid;		/* UID of user to deliver to */
     struct idlist *skipped;	/* messages skipped on the mail server */
     struct idlist *oldsaved, *newsaved;
+    flag have_uids;		/* have we seen UIDs during this query? */
     char *lastid;		/* last Message-ID seen on this connection */
 
     /* internal use -- per-message state */
diff --git a/uid.c b/uid.c
index ba99fd5f..2f388a23 100644
--- a/uid.c
+++ b/uid.c
@@ -424,11 +424,24 @@ void uid_end_query(struct query *ctl)
 	report_complete(stdout, "\n");
     }
 
-    /* old state of mailbox may now be irrelevant */
-    free_str_list(&ctl->oldsaved);
-    free_str_list(&scratchlist);
-    ctl->oldsaved = ctl->newsaved;
-    ctl->newsaved = (struct idlist *) NULL;
+    /*
+     * 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.
+     */
+    if (ctl->have_uids)
+    {
+	/* old state of mailbox may now be irrelevant */
+	if (outlevel >= O_DEBUG)
+	    report(stdout, "swapping UID lists\n");
+	free_str_list(&ctl->oldsaved);
+	free_str_list(&scratchlist);
+	ctl->oldsaved = ctl->newsaved;
+	ctl->newsaved = (struct idlist *) NULL;
+	ctl->have_uids = FALSE;
+    }
+    else if (outlevel >= O_DEBUG)
+	report(stdout, "not swapping UID lists, no UIDs seen this query\n");
 }
 
 void write_saved_lists(struct query *hostlist, const char *idfile)