From: Eric S. Raymond <esr@thyrsus.com>
Date: Thu, 26 Mar 1998 19:43:14 +0000 (-0000)
Subject: Use TOP instead of RETR for POP3 retrieval.
X-Git-Url: http://pileus.org/git/?a=commitdiff_plain;h=cacba6b362fb7907d1bb2d529e95504b27a00d25;p=~andy%2Ffetchmail

Use TOP instead of RETR for POP3 retrieval.

svn path=/trunk/; revision=1727
---

diff --git a/NEWS b/NEWS
index d2e5e244..2c88a751 100644
--- a/NEWS
+++ b/NEWS
@@ -14,6 +14,9 @@
 				Release Notes:
 
 ------------------------------------------------------------------------------
+fetchmail-4.4.2 ():
+* Use TOP for POP3 retrieval to avoid marking messages seen.  Duh!
+
 fetchmail-4.4.1 (Tue Mar 24 00:01:20 EST 1998):
 * We now properly shroud IMAP passwords containing ", \, and SP.
 * Checked for Y2K safety.  No 2-digit dates anywhere, so we're safe.
diff --git a/driver.c b/driver.c
index 6963ea80..5257819a 100644
--- a/driver.c
+++ b/driver.c
@@ -2029,11 +2029,13 @@ const struct method *proto;	/* protocol method table */
 		    flag	force_retrieval;
 
 		    /*
-		     * What forces this code is that in POP3 and
-		     * IMAP2BIS you can't fetch a message without
-		     * having it marked `seen'.  In IMAP4, on the
-		     * other hand, you can (peek_capable is set to
-		     * convey this).
+		     * What forces this code is that in POP2 and
+		     * IMAP2bis you can't fetch a message without
+		     * having it marked `seen'.  In POP3 and IMAP4, on the
+		     * other hand, you can (peek_capable is set by 
+		     * each driver module to convey this; it's not a
+		     * method constant because of the difference between
+		     * IMAP2bis and IMAP4).
 		     *
 		     * The result of being unable to peek is that if there's
 		     * any kind of transient error (DNS lookup failure, or
@@ -2477,7 +2479,7 @@ int size;	/* length of buffer */
 	if (buf[strlen(buf)-1] == '\n')
 	    buf[strlen(buf)-1] = '\0';
 	if (buf[strlen(buf)-1] == '\r')
-	    buf[strlen(buf)-1] = '\r';
+	    buf[strlen(buf)-1] = '\0';
 	if (outlevel == O_VERBOSE)
 	    error(0, 0, "%s< %s", protocol->name, buf);
 	phase = oldphase;
diff --git a/pop3.c b/pop3.c
index 75fa0082..ffcb6469 100644
--- a/pop3.c
+++ b/pop3.c
@@ -234,6 +234,9 @@ int pop3_getauth(int sock, struct query *ctl, char *greeting)
      */
     sleep(3); /* to be _really_ safe, probably need sleep(5)! */
 
+    /* we're peek-capable because the TOP command exists */
+    peek_capable = TRUE;
+
     /* we're approved */
     return(PS_SUCCESS);
 }
@@ -519,7 +522,29 @@ static int pop3_fetch(int sock, struct query *ctl, int number, int *lenp)
 
     /* phase = PHASE_FETCH */
 
-    gen_send(sock, "RETR %d", number);
+    /*
+     * Though the POP RFCs don't document this fact, on every POP3 server
+     * I know of messages are marked "seen" only at the time the OK
+     * response to a RETR is issued.
+     *
+     * This means we can use TOP to fetch the message without setting its
+     * seen flag.  This is good!  It means that if the protocol exchange
+     * craps out during the message, it will still be marked `unseen' on
+     * the server.
+     *
+     * The line count passed is the maximum value of a twos-complement
+     * signed integer (we take advantage of the fact that, according
+     * to all the POP RFCs, "if the number of lines requested by the
+     * POP3 client is greater than than the number of lines in the
+     * body, then the POP3 server sends the entire message.").
+     *
+     * However...*don't* do this if we're using keep to suppress deletion!
+     * In that case, marking the seen flag is the only way to prevent the
+     * message from being re-fetched on subsequent runs.  */
+    if (ctl->keep)
+	gen_send(sock, "RETR %d", number);
+    else
+	gen_send(sock, "TOP %d 2147483647", number);
     if ((ok = pop3_ok(sock, buf)) != 0)
 	return(ok);