UIDs are back in.

svn path=/trunk/; revision=285

6 files changed, 88 insertions, 14 deletions

diff --git a/Makefile.in b/Makefile.in
index d502f717..81975167 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -73,7 +73,7 @@ CTAGS = ctags -tw
 
 popobjs = socket.o getpass.o pop2.o pop3.o imap.o fetchmail.o options.o	\
        rcfile_l.o rcfile_y.o rcfile.o daemon.o driver.o smtp.o xmalloc.o \
-       md5c.o md5ify.o
+       uid.o md5c.o md5ify.o
 
 objs = $(popobjs) $(extras) $(EXTRAOBJ)
 
@@ -81,7 +81,7 @@ srcs = $(srcdir)/socket.c $(srcdir)/getpass.c $(srcdir)/pop2.c 		\
        $(srcdir)/pop3.c $(srcdir)/imap.c $(srcdir)/fetchmail.c		\
        $(srcdir)/options.c $(srcdir)/rcfile.c $(srcdir)/daemon.c 	\
        $(srcdir)/driver.c $(srcdir)/smtp.c $(srcdir)/xmalloc.c 		\
-       $(srcdir)/md5c.c $(srcdir)/md5ify.c
+       $(srcdir)/uid.c $(srcdir)/md5c.c $(srcdir)/md5ify.c
 
 .SUFFIXES:
 .SUFFIXES: .o .c .h .y .l .ps .dvi .info .texi
diff --git a/NEWS b/NEWS
index 37d4aa1c..6fb6dd2d 100644
--- a/NEWS
+++ b/NEWS
@@ -37,6 +37,8 @@ features --
 * New --check option for asking server whether there is mail without
   actually retrieving or deleting it.
 
+* UID support is back by popular demand.  Bletch.
+
 bugs --
 
 * Fix buggy getopt specification of P and p options.
diff --git a/fetchmail.c b/fetchmail.c
index 7d9073c8..d65de5f4 100644
--- a/fetchmail.c
+++ b/fetchmail.c
@@ -58,6 +58,7 @@ int check_only;		/* if --probe was set */
 
 /* miscellaneous global controls */
 char *rcfile;		/* path name of rc file */
+char *idfile;		/* UID list file */
 int versioninfo;	/* emit only version info */
 
 /*********************************************************************
@@ -130,6 +131,12 @@ char **argv;
     strcat(rcfile, "/");
     strcat(rcfile, tmpdir);
 
+#define IDFILE_NAME	".fetchids"
+    idfile = (char *) xmalloc(strlen(home)+strlen(IDFILE_NAME)+2);
+    strcpy(idfile, home);
+    strcat(idfile, "/");
+    strcat(idfile, IDFILE_NAME);
+  
     outlevel = O_NORMAL;
 
     if ((parsestatus = parsecmdline(argc,argv,&cmd_opts)) < 0)
@@ -233,6 +240,12 @@ char **argv;
     strcat(tmpbuf, "/fetchmail-");
     strcat(tmpbuf, user);
 
+    /* initialize UID handling */
+    if ((st = prc_filecheck(idfile)) != 0)
+	exit(st);
+    else
+	initialize_saved_lists(hostlist, idfile);
+
     /* perhaps we just want to check options? */
     if (versioninfo) {
 	    printf("Taking options from command line");
@@ -351,7 +364,10 @@ char **argv;
     do {
 	for (hostp = hostlist; hostp; hostp = hostp->next) {
 	    if (hostp->active && !(implicitmode && hostp->skip))
+	    {
 		popstatus = query_host(hostp);
+ 		update_uid_lists(hostp);
+	    }
 	}
 
 	sleep(poll_interval);
@@ -371,6 +387,8 @@ void termhook(int sig)
     if (sig != 0)
 	fprintf(stderr, "terminated with signal %d\n", sig);
 
+    write_saved_lists(hostlist, idfile);
+
     unlink(lockfile);
     exit(popstatus);
 }
@@ -520,6 +538,22 @@ struct hostrec *queryctl;
     }
     else
 	printf("  Messages will be SMTP-forwarded to '%s'\n", queryctl->smtphost);
+    if (queryctl->protocol > P_POP2)
+	if (!queryctl->saved)
+	    printf("  No UIDs saved from this host.\n");
+	else
+	{
+	    struct idlist *idp;
+	    int count = 0;
+
+	    for (idp = hostp->saved; idp; idp = idp->next)
+		++count;
+
+	    printf("  %d UIDs saved.\n", count);
+	    if (outlevel == O_VERBOSE)
+		for (idp = hostp->saved; idp; idp = idp->next)
+		    fprintf(stderr, "\t%s %s\n", hostp->servername, idp->id);
+	}
 }
 
 /*********************************************************************
diff --git a/fetchmail.h b/fetchmail.h
index a5dcb39c..8c4ee3a3 100644
--- a/fetchmail.h
+++ b/fetchmail.h
@@ -55,6 +55,13 @@
 
 #define		SIZETICKER	1024	/* print 1 dot per this many bytes */
 
+struct idlist
+{
+    int num;
+    char *id;
+    struct idlist *next;
+};
+
 struct hostrec
 {
     /* per-host data */
@@ -80,6 +87,9 @@ struct hostrec
     int norewrite;
     int skip;
 
+    /* current, previous state of mailbox (initially from .fetchids) */
+    struct idlist *saved, *current;
+
     /* internal use */
     int active;
     struct hostrec *next;	/* next host in chain */
@@ -121,6 +131,7 @@ extern int check_only;		/* if --check was set */
 
 /* miscellaneous global controls */
 extern char *rcfile;		/* path name of rc file */
+extern char *idfile;		/* path name of UID file */
 extern int linelimit;		/* limit # lines retrieved per site */
 extern int versioninfo;		/* emit only version info */
 
@@ -134,6 +145,14 @@ int doPOP2 (struct hostrec *);
 int doPOP3 (struct hostrec *);
 int doIMAP (struct hostrec *);
 
+void initialize_saved_lists(struct hostrec *, char *);
+void save_uid(struct idlist **, int, char *);
+void free_uid_list(struct idlist **);
+int delete_uid(struct idlist **, char *);
+int uid_in_list(struct idlist **, char *);
+void update_uid_lists(struct hostrec *);
+void write_saved_lists(struct hostrec *, char *);
+
 struct hostrec *hostalloc(struct hostrec *); 
 int parsecmdline (int, char **, struct hostrec *);
 void optmerge(struct hostrec *, struct hostrec *);
diff --git a/fetchmail.man b/fetchmail.man
index 13a4df11..c0a5f8e8 100644
--- a/fetchmail.man
+++ b/fetchmail.man
@@ -85,6 +85,10 @@ Specify a non-default name for the
 .I .fetchmailrc
 run control file.
 .TP
+.B \-i pathname, --idfile pathname
+Specify an alternate name for the .fetchids file used to save POP3
+UIDs. 
+.TP
 .B \-k, --keep
 Keep retrieved messages in folder on remote mailserver.  Normally, messages 
 are deleted from the folder on the mailserver after they have been retrieved.
@@ -300,13 +304,15 @@ One could be that you're using POP2.  The POP2 protocol includes no
 representation of `new' or `old' state in messages, so \fIfetchmail\fR
 must treat all messages as new all the time.  POP2 is obsolete.
 .PP
-Under POP3, blame RFC1725.  That late version of the POP3 protocol
-specification ill-advisedly removed the LAST command, and some POP
-servers (including the one distributed with at least some versions of
-SunOS) follow it (you can verify this by invoking \fIfetchmail -v\fR
-to the mail server and watching the response to LAST early in the
-query).  The fix is to install an older POP3 server with LAST or
-(better) switch to an IMAP server.
+Under POP3, blame RFC1725.  That version of the POP3 protocol
+specification removed the LAST command, and some POP servers follow it
+(you can verify this by invoking \fIfetchmail -v\fR to the mail server
+and watching the response to LAST early in the query).  The
+\fIfetchmail\fR code tries to compensate by using POP3's UID feature,
+storing the identifiers of messages seen in each session until the
+next session,in the \fI.fetchids\fR file.  But this doesn't track
+messages seen with other clients or read but not deleted directly with
+a mailer on the host.  A better solution would be to switch to IMAP.
 .PP
 Another potential POP3 problem might be servers that insert messages
 in the middle of mailboxes (some VMS implementations of mail are
@@ -580,6 +586,11 @@ created by the new SMTP forwarding default.
 ~/.fetchmailrc
 default run control file
 .TP 5
+~/.fetchids
+default location of file associating hosts with last message IDs seen
+(used only with newer RFC1725-compliant POP3 servers supporting the
+UIDL command).
+.TP 5
 ${TMPDIR}/fetchmail-${HOST}-${USER}
 lock file to help prevent concurrent runs.
 .SH ENVIRONMENT
diff --git a/options.c b/options.c
index 77e29f16..cc6efff1 100644
--- a/options.c
+++ b/options.c
@@ -36,11 +36,12 @@
 #define LA_SMTPHOST	16
 #define LA_MDA		17
 #define LA_LOGFILE	18
-#define LA_QUIT		19
-#define LA_NOREWRITE	20
-#define LA_CHECK	21
-#define LA_HELP		22
-#define LA_YYDEBUG	23
+#define LA_IDFILE	19
+#define LA_QUIT		20
+#define LA_NOREWRITE	21
+#define LA_CHECK	22
+#define LA_HELP		23
+#define LA_YYDEBUG	24
 
 static char *shortoptions = "P:p:VaKkvS:m:sFd:f:u:r:L:qN?";
 static struct option longoptions[] = {
@@ -63,6 +64,7 @@ static struct option longoptions[] = {
   {"smtphost",	required_argument, (int *) 0, LA_SMTPHOST   },
   {"mda",	required_argument, (int *) 0, LA_MDA        },
   {"logfile",	required_argument, (int *) 0, LA_LOGFILE    },
+  {"idfile",	required_argument, (int *) 0, LA_IDFILE     },
   {"quit",	no_argument,	   (int *) 0, LA_QUIT       },
   {"norewrite",	no_argument,	   (int *) 0, LA_NOREWRITE  },
   {"check",	no_argument,	   (int *) 0, LA_CHECK      },
@@ -174,6 +176,11 @@ struct hostrec *queryctl;
         rcfile = (char *) xmalloc(strlen(optarg)+1);
         strcpy(rcfile,optarg);
         break;
+      case 'i':
+      case LA_IDFILE:
+        idfile = (char *) xmalloc(strlen(optarg)+1);
+        strcpy(idfile,optarg);
+        break;
       case 'u':
       case LA_USERNAME:
         strncpy(queryctl->remotename,optarg,sizeof(queryctl->remotename)-1);
@@ -248,6 +255,7 @@ struct hostrec *queryctl;
     fputs("  -L, --logfile     specify logfile name\n", stderr);
     fputs("  -q, --quit        kill daemon process\n", stderr);
     fputs("  -f, --fetchmailrc specify alternate run control file\n", stderr);
+    fputs("  -i, --idfile      specify alternate UIDs file\n", stderr);
 
     fputs("  -p, --protocol    specify pop2, pop3, imap, apop, rpop, kpop\n", stderr);
     fputs("  -P, --port        TCP/IP service port to connect to\n",stderr);