Optimized isync by not fetching the sizes of messages if they are

unneeded (i.e., if MaxSize is not specified in the config file).

Patch and idea originally from Nicolas Boullis <nboullis@debian.org>,
modified/polished by Theodore Ts'o per comments by Oswald Buddenhagen.

debian/patches/00list

@@ -1,3 +1 @@
-10-size-opt.dpatch
 20-cleanup.dpatch
-

debian/patches/10-size-opt.dpatch

@@ -1,81 +0,0 @@
-#! /bin/sh -e
-## 10-size-opt.dpatch by Nicolas Boullis <nboullis@debian.org> 
-##
-## DP: This patch from Nicolas Boullis <nboullis@debian.org> optimizes isync
-## DP: by not fetching the sizes of messages if they are unneeded (i.e., if
-## DP: MaxSize is not specified in the config file).
-
-[ -f debian/patches/00patch-opts ] && . debian/patches/00patch-opts
-patch_opts="${patch_opts:--f --no-backup-if-mismatch}"
-
-if [ $# -ne 1 ]; then
-    echo >&2 "`basename $0`: script expects -patch|-unpatch as argument"
-    exit 1
-fi
-case "$1" in
-       -patch) patch $patch_opts -p1 < $0;;
-       -unpatch) patch $patch_opts -p1 -R < $0;;
-	*)
-		echo >&2 "`basename $0`: script expects -patch|-unpatch as argument"
-		exit 1;;
-esac
-
-exit 0
-@DPATCH@
-
-===================================================================
-RCS file: isync-0.9.2/src/RCS/isync.h,v
-retrieving revision 1.1
-diff -u -r1.1 isync-0.9.2/src/isync.h
---- isync-0.9.2/src/isync.h	2004/01/09 23:06:52	1.1
-+++ isync-0.9.2/src/isync.h	2004/01/09 23:07:08
-@@ -205,7 +205,7 @@
- int imap_set_flags (imap_t *, unsigned int, unsigned int);
- int imap_expunge (imap_t *);
- imap_t *imap_connect (config_t *);
--imap_t *imap_open (config_t *, unsigned int, imap_t *, int);
-+imap_t *imap_open (config_t *, unsigned int, imap_t *, int, int);
- int imap_append_message (imap_t *, int, message_t *);
- int imap_list (imap_t *);
- 
-===================================================================
-RCS file: isync-0.9.2/src/RCS/imap.c,v
-retrieving revision 1.1
-diff -u -r1.1 isync-0.9.2/src/imap.c
---- isync-0.9.2/src/imap.c	2004/01/09 23:08:20	1.1
-+++ isync-0.9.2/src/imap.c	2004/01/09 23:09:54
-@@ -874,7 +874,8 @@
-  * mailbox.
-  */
- imap_t *
--imap_open (config_t * box, unsigned int minuid, imap_t * imap, int imap_create)
-+imap_open (config_t * box, unsigned int minuid, imap_t * imap, 
-+	   int imap_create, int get_size)
- {
-   if (imap)
-   {
-@@ -940,7 +941,8 @@
-     imap->minuid = minuid;
-     if (imap->count > 0)
-     {
--      if (imap_exec (imap, "UID FETCH %d:* (FLAGS RFC822.SIZE)", minuid))
-+      if (imap_exec (imap, "UID FETCH %d:* (FLAGS%s)", minuid, 
-+		     get_size ? " RFC822.SIZE" : ""))
- 	goto bail;
-     }
- 
-===================================================================
-RCS file: isync-0.9.2/src/RCS/main.c,v
-retrieving revision 1.1
-diff -u -r1.1 isync-0.9.2/src/main.c
---- isync-0.9.2/src/main.c	2004/01/09 23:08:20	1.1
-+++ isync-0.9.2/src/main.c	2004/01/09 23:08:31
-@@ -396,7 +396,7 @@
- 		break;
- 	    }
- 
--	    imap = imap_open (box, fast ? mail->maxuid + 1 : 1, imap, imap_create);
-+	    imap = imap_open (box, fast ? mail->maxuid + 1 : 1, imap, imap_create, box->max_size!=0);
- 	    if (!imap)
- 	    {
- 		fprintf (stderr, "%s: skipping mailbox due to IMAP error\n",

src/imap.c

@@ -874,7 +874,7 @@ mstrcmp (const char *s1, const char *s2)
  * mailbox.
  */
 imap_t *
-imap_open (config_t * box, unsigned int minuid, imap_t * imap, int imap_create)
+imap_open (config_t * box, unsigned int minuid, imap_t * imap, int imap_flags)
 {
   if (imap)
   {
@@ -926,7 +926,7 @@ imap_open (config_t * box, unsigned int minuid, imap_t * imap, int imap_create)
     info ("Selecting IMAP mailbox... ");
     fflush (stdout);
     if (imap_exec (imap, "SELECT \"%s%s\"", imap->prefix, box->box)) {
-      if (imap_create) {
+      if (imap_flags & IMAP_CREATE) {
 	if (imap_exec (imap, "CREATE \"%s%s\"", imap->prefix, box->box))
 	  goto bail;
         if (imap_exec (imap, "SELECT \"%s%s\"", imap->prefix, box->box))
@@ -940,7 +940,8 @@ imap_open (config_t * box, unsigned int minuid, imap_t * imap, int imap_create)
     imap->minuid = minuid;
     if (imap->count > 0)
     {
-      if (imap_exec (imap, "UID FETCH %d:* (FLAGS RFC822.SIZE)", minuid))
+      if (imap_exec (imap, "UID FETCH %d:* (FLAGS%s)", minuid, 
+		     (imap_flags & IMAP_GET_SIZE) ? " RFC822.SIZE" : ""))
 	goto bail;
     }
 

src/isync.h

@@ -171,6 +171,11 @@ imap_t;
 #define OPEN_FAST	(1<<0)	/* fast open - don't parse */
 #define OPEN_CREATE	(1<<1)	/* create mailbox if nonexistent */
 
+/* flags for imap_open */
+#define IMAP_CREATE	(1<<0)	/* Create remote mailboxes if necessary */
+#define IMAP_GET_SIZE	(1<<1)	/* Request the RFC 822 SIZE */
+
+
 extern config_t global;
 extern config_t *boxes;
 extern unsigned int Tag;

src/main.c

@@ -197,7 +197,7 @@ main (int argc, char **argv)
     int list = 0;
     int o2o = 0;
     int mbox_open_mode = 0;
-    int imap_create = 0;
+    int imap_flags = 0;
 
     pw = getpwuid (getuid ());
 
@@ -240,13 +240,13 @@ main (int argc, char **argv)
 		break;
 	    case 'C':
 		mbox_open_mode |= OPEN_CREATE;
-		imap_create = 1;
+		imap_flags |= IMAP_CREATE;
 		break;
 	    case 'L':
 		mbox_open_mode |= OPEN_CREATE;
 		break;
 	    case 'R':
-		imap_create = 1;
+		imap_flags |= IMAP_CREATE;
 		break;
 	    case 'c':
 		config = optarg;
@@ -403,7 +403,9 @@ main (int argc, char **argv)
 		break;
 	    }
 
-	    imap = imap_open (box, fast ? mail->maxuid + 1 : 1, imap, imap_create);
+	    if (box->max_size)
+		imap_flags |= IMAP_GET_SIZE;
+	    imap = imap_open (box, fast ? mail->maxuid + 1 : 1, imap, imap_flags);
 	    if (!imap)
 	    {
 		fprintf (stderr, "%s: skipping mailbox due to IMAP error\n",