Hi again, I had some troubles simplifying the UTF-7 transcoding in an elegant way and without code duplication. But I think there is an easier solution to the problem, which involves fewer hoops and less code.
The [RFC 6855][1] specifies the UTF8=ACCEPT and UTF8=ONLY IMAP server capabilities, which are the same (except one is mandatory). The only thing the client has to do is issue an "ENABLE UTF8=ACCEPT" command to activate the use of the extension. I tested that with the patch below, and it seems to work. As far as I can tell, the extension allow to use UTF8 in quoted strings, no particular gotchas in the syntax (section 3 of the RFC) but as I'm not overly familiar with IMAP, I might have missed some. The patch below is just enough to make it work (on my setup) ; I was not sure where exactly I should insert the IMAP command execution, since it seems there is several execution paths in the imap_open_store_*, and I'm not sure I understand it right. Where do you think the code should go ? Additional things to think about : - I don't know how widely that extension is implemented. I can say gmail imap does it, since it is what I use, but other IMAP servers might not provide this extension. So it might be less useful than the previous approach (transcoding from UTF7 IMAP). - It might not be necessary to check for UTF8=ACCEPT in the capabilities before sending the ENABLE command. If I read [RFC 5161][2] (specifying the ENABLE extension for IMAP) correctly, the server is supposed to ignore unknowns extension, so checking for ENABLE might be enough (section 3.1). [1]: https://tools.ietf.org/html/rfc6855 [2]: https://tools.ietf.org/html/rfc5161 Max Gautier --- src/drv_imap.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/src/drv_imap.c b/src/drv_imap.c index 7bc88f6..88b2dbe 100644 --- a/src/drv_imap.c +++ b/src/drv_imap.c @@ -216,7 +216,9 @@ enum CAPABILITY { LITERALPLUS, MOVE, NAMESPACE, - COMPRESS_DEFLATE + COMPRESS_DEFLATE, + UTF8_ACCEPT, + UTF8_ONLY }; static const char *cap_list[] = { @@ -231,7 +233,9 @@ static const char *cap_list[] = { "LITERAL+", "MOVE", "NAMESPACE", - "COMPRESS=DEFLATE" + "COMPRESS=DEFLATE", + "UTF8=ACCEPT", + "UTF8=ONLY" }; #define RESP_OK 0 @@ -2231,9 +2235,16 @@ imap_open_store_authenticate2_p2( imap_store_t *ctx, imap_cmd_t *cmd ATTR_UNUSED imap_open_store_compress( ctx ); } +static void +imap_handle_simple_cmd( imap_store_t *ctx ATTR_UNUSED, + imap_cmd_t *cmd ATTR_UNUSED, + int response ATTR_UNUSED) { +} static void imap_open_store_compress( imap_store_t *ctx ) { + if (CAP(UTF8_ACCEPT) || CAP(UTF8_ONLY)) + imap_exec(ctx, 0, imap_handle_simple_cmd, "ENABLE UTF8=ACCEPT"); #ifdef HAVE_LIBZ if (CAP(COMPRESS_DEFLATE)) { imap_exec( ctx, 0, imap_open_store_compress_p2, "COMPRESS DEFLATE" ); -- 2.26.2 _______________________________________________ isync-devel mailing list isync-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/isync-devel
