From d94dadbaebc8c71818f7b3e8e6753a48d6ff8d8a Mon Sep 17 00:00:00 2001
From: Oswald Buddenhagen <ossi@users.sf.net>
Date: Sat, 6 Feb 2010 10:34:41 +0100
Subject: [PATCH] fix line ending conversion logic

imap may very well store messages with LF line endings. only RFC2822
requires CRLF.
consequently, preserve the line endings as much as possible unless the
mailbox format does not support it (this would be the case for unix mbox
- i actually have no idea about maildir).
---
 src/drv_maildir.c |  2 +-
 src/isync.h       |  5 +++
 src/sync.c        | 81 +++++++++++++++++++++++++----------------------
 3 files changed, 50 insertions(+), 38 deletions(-)

diff --git a/src/drv_maildir.c b/src/drv_maildir.c
index d8779f5..80a7cac 100644
--- a/src/drv_maildir.c
+++ b/src/drv_maildir.c
@@ -1250,7 +1250,7 @@ maildir_parse_store( conffile_t *cfg, store_conf_t **storep, int *err )
 }
 
 struct driver maildir_driver = {
-	0,
+	0, /* XXX DRV_CRLF? */
 	maildir_parse_store,
 	maildir_cleanup_drv,
 	maildir_open_store,
diff --git a/src/isync.h b/src/isync.h
index cd3e750..8e7ec51 100644
--- a/src/isync.h
+++ b/src/isync.h
@@ -174,6 +174,11 @@ typedef struct {
 
 /* All memory belongs to the driver's user. */
 
+/*
+   This flag says that the driver CAN store messages with CRLFs,
+   not that it must. The lack of it OTOH implies that it CANNOT,
+   and as CRLF is the canonical format, we convert.
+*/
 #define DRV_CRLF        1
 
 #define TUIDL 12
diff --git a/src/sync.c b/src/sync.c
index b1c4a46..8c2f6b5 100644
--- a/src/sync.c
+++ b/src/sync.c
@@ -211,7 +211,7 @@ msg_fetched( int sts, void *aux )
 	copy_vars_t *vars = (copy_vars_t *)aux;
 	SVARS(vars->aux)
 	char *fmap, *buf;
-	int i, len, extra, cra, crd, scr, tcr, crds;
+	int i, len, extra, scr, tcr, lcrs, crs, lines;
 	int start, sbreak = 0, ebreak = 0;
 	char c;
 
@@ -224,29 +224,24 @@ msg_fetched( int sts, void *aux )
 		if (vars->srec || scr != tcr) {
 			fmap = vars->data.data;
 			len = vars->data.len;
-			cra = crd = 0;
-			if (scr > tcr)
-				crd = -1;
-			else if (scr < tcr)
-				cra = 1;
-			extra = 0, i = 0;
+			extra = lines = crs = i = 0;
 			if (vars->srec) {
-				extra += 8 + TUIDL + 1 + tcr;
 			  nloop:
 				start = i;
-				crds = 0;
+				lcrs = 0;
 				while (i < len) {
 					c = fmap[i++];
 					if (c == '\r')
-						crds += crd;
+						lcrs++;
 					else if (c == '\n') {
 						if (!memcmp( fmap + start, "X-TUID: ", 8 )) {
-							extra -= (ebreak = i) - (sbreak = start);
+							extra = (sbreak = start) - (ebreak = i);
 							goto oke;
 						}
-						extra += cra + crds;
-						if (i - 1 - scr == start) {
-							sbreak = ebreak = i - 1 - scr;
+						lines++;
+						crs += lcrs;
+						if (i - lcrs - 1 == start) {
+							sbreak = ebreak = start;
 							goto oke;
 						}
 						goto nloop;
@@ -257,54 +252,66 @@ msg_fetched( int sts, void *aux )
 				      vars->msg->uid, str_ms[1-t] );
 				free( fmap );
 				return vars->cb( SYNC_NOGOOD, 0, vars );
+			  oke:
+				extra += 8 + TUIDL + 1 + (tcr && crs);
 			}
-		  oke:
-			if (cra || crd)
+			if (tcr != scr) {
 				for (; i < len; i++) {
 					c = fmap[i];
 					if (c == '\r')
-						extra += crd;
+						crs++;
 					else if (c == '\n')
-						extra += cra;
+						lines++;
 				}
+				extra -= crs;
+				if (tcr)
+					extra += lines;
+			}
 
 			vars->data.len = len + extra;
 			buf = vars->data.data = nfmalloc( vars->data.len );
 			i = 0;
 			if (vars->srec) {
-				if (cra) {
-					for (; i < sbreak; i++) {
-						if (fmap[i] == '\n')
-							*buf++ = '\r';
-						*buf++ = fmap[i];
+				if (tcr != scr) {
+					if (tcr) {
+						for (; i < sbreak; i++)
+							if ((c = fmap[i]) != '\r') {
+								if (c == '\n')
+									*buf++ = '\r';
+								*buf++ = c;
+							}
+					} else {
+						for (; i < sbreak; i++)
+							if ((c = fmap[i]) != '\r')
+								*buf++ = c;
 					}
-				} else if (crd) {
-					for (; i < sbreak; i++)
-						if (fmap[i] != '\r')
-							*buf++ = fmap[i];
 				} else {
 					memcpy( buf, fmap, sbreak );
 					buf += sbreak;
 				}
+
 				memcpy( buf, "X-TUID: ", 8 );
 				buf += 8;
 				memcpy( buf, vars->srec->tuid, TUIDL );
 				buf += TUIDL;
-				if (tcr)
+				if (tcr && crs)
 					*buf++ = '\r';
 				*buf++ = '\n';
 				i = ebreak;
 			}
-			if (cra) {
-				for (; i < len; i++) {
-					if (fmap[i] == '\n')
-						*buf++ = '\r';
-					*buf++ = fmap[i];
+			if (tcr != scr) {
+				if (tcr) {
+					for (; i < len; i++)
+						if ((c = fmap[i]) != '\r') {
+							if (c == '\n')
+								*buf++ = '\r';
+							*buf++ = c;
+						}
+				} else {
+					for (; i < len; i++)
+						if ((c = fmap[i]) != '\r')
+							*buf++ = c;
 				}
-			} else if (crd) {
-				for (; i < len; i++)
-					if (fmap[i] != '\r')
-						*buf++ = fmap[i];
 			} else
 				memcpy( buf, fmap + i, len - i );