[cups.bugs] [HIGH] STR #3920: printers are no longer visible as of CUPS 1.4.7 (HTTP related problem?)

[Vincent Lefèvre]

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[STR New]

With the CUPS clients 1.4.7, 1.4.8 and 1.5.0, the printers are no longer
visible. No problems with 1.4.6. For instance:

ypig:~> lpq -Plip-multi-3
lpq: Unknown destination "lip-multi-3"!
ypig:~> lpq
lpq: error - no default destination available.

while with 1.4.6:

ypig:~> lpq
lip-multi-3 is ready
no entries

The problem is in the library.

Operating system: GNU/Linux (Debian/sid with the CUPS Debian packages).

/etc/cups/client.conf contains:
ServerName lip-printserver1.lip.ens-lyon.fr

The other lines are comments and empty lines.

Here's my bug report on the Debian BTS:
  http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=635096

In particular, a strace comparison of "lpq" shows:

With libcups2 1.4.6-11+b1 (working):

[...]
8954  sendto(5, "POST / HTTP/1.1\r\nContent-Length:"..., 157, 0, NULL, 0)
= 157
8954  sendto(5, "\1\1@\2\0\0\0\1\1G\0\22attributes-charset\0\5"..., 636,
0, NULL, 0) = 636
8954  poll([{fd=5, events=POLLIN}], 1, 1000) = 1 ([{fd=5,
revents=POLLIN|POLLERR|POLLHUP}])
8954  recvfrom(5, "HTTP/1.1 426 Upgrade Required\r\nD"..., 2048, 0, NULL,
NULL) = 794
8954  close(5)                          = 0
8954  socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 5
8954  setsockopt(5, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
8954  setsockopt(5, SOL_TCP, TCP_NODELAY, [1], 4) = 0
8954  fcntl(5, F_SETFD, FD_CLOEXEC)     = 0
8954  connect(5, {sa_family=AF_INET, sin_port=htons(631),
sin_addr=inet_addr("140.77.14.157")}, 16) = 0
8954  sendto(5, "OPTIONS * HTTP/1.1\r\nConnection: "..., 141, 0, NULL, 0)
= 141
8954  recvfrom(5, "HTTP/1.1 101 Switching Protocols"..., 2048, 0, NULL,
NULL) = 231
[...]

With libcups2 1.4.7-1 (broken):

[...]
11411 sendto(5, "POST / HTTP/1.1\r\nContent-Length:"..., 157, 0, NULL, 0)
= 157
11411 sendto(5, "\1\1@\2\0\0\0\1\1G\0\22attributes-charset\0\5"..., 636,
0, NULL, 0) = 636
11411 poll([{fd=5, events=POLLIN}], 1, 1000) = 1 ([{fd=5,
revents=POLLIN|POLLERR|POLLHUP}])
11411 recvfrom(5, "HTTP/1.1 426 Upgrade Required\r\nD"..., 2048, 0, NULL,
NULL) = 794
11411 close(5)                          = 0
11411 socket(PF_INET, SOCK_STREAM, IPPROTO_IP) = 5
11411 setsockopt(5, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
11411 setsockopt(5, SOL_TCP, TCP_NODELAY, [1], 4) = 0
11411 fcntl(5, F_SETFD, FD_CLOEXEC)     = 0
11411 connect(5, {sa_family=AF_INET, sin_port=htons(631),
sin_addr=inet_addr("140.77.14.157")}, 16) = 0
11411 sendto(5, "OPTIONS * HTTP/1.1\r\nConnection: "..., 141, 0, NULL, 0)
= 141
11411 close(5)                          = 0
11411 write(2, "lpq: error - no default destinat"..., 47) = 47
[...]

Link: http://www.cups.org/str.php?L3920
Version: 1.5.0