Comment 5 for bug 936647

Stracing "lpq -a -l" ends with this:

socket(PF_FILE, SOCK_STREAM, 0) = 4
setsockopt(4, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
setsockopt(4, SOL_TCP, TCP_NODELAY, [1], 4) = -1 EOPNOTSUPP (Operation not supported)
fcntl(4, F_SETFD, FD_CLOEXEC) = 0
connect(4, {sa_family=AF_FILE, path="/var/run/cups/cups.sock"}, 26) = 0
sendto(4, "POST / HTTP/1.1\r\nContent-Length: 260\r\nContent-Type: application/ipp\r\nHost: localhost\r\nUser-Agent: CUPS/1.5.2\r\nExpect: 100-continue\r\n\r\n", 134, 0, NULL, 0) = 134
sendto(4, "\1\1\0\n\0\0\0\1\1G\0\22attributes-charset\0\5utf-8H\0\33attributes-natural-language\0\5de-deE\0\vprinter-uri\0\20ipp://localhost/D\0\24requested-attributes\0\6copiesD\0\0\0\6job-idD\0\0\0\fjob-k-octetsD\0\0\0\10job-nameD\0\0\0\31job-originating-user-nameD\0\0\0\17job-printer-uriD\0\0\0\fjob-priorityD\0\0\0\tjob-state\3", 260, 0, NULL, 0) = 260
poll([{fd=4, events=POLLIN}], 1, 1000) = 1 ([{fd=4, revents=POLLIN}])
poll([{fd=4, events=POLLIN}], 1, 60000) = 1 ([{fd=4, revents=POLLIN}])
recvfrom(4, "HTTP/1.1 100 Continue\r\n\r\nHTTP/1.1 200 OK\r\nDate: Thu, 08 Mar 2012 22:06:31 GMT\r\nServer: CUPS/1.5\r\nConnection: Keep-Alive\r\nKeep-Alive: timeout=30\r\nContent-Language: en_US\r\nContent-Type: application/ipp\r\nContent-Length: 75\r\n\r\n\1\1\0\0\0\0\0\1\1G\0\22attributes-charset\0\5utf-8H\0\33attributes-natural-language\0\5de-de\3", 2048, 0, NULL, NULL) = 298
fstat(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 3), ...}) = 0
mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f88eb555000
write(1, "\n", 1
) = 1
close(4) = 0
exit_group(0) = ?

This is the only communication through the socket, and that single line feed is the only thing it writes to stdout.
At the same time, the cups debug log says:

D [08/Mar/2012:23:15:16 +0100] cupsdAcceptClient: 18 from localhost (Domain)
D [08/Mar/2012:23:15:16 +0100] cupsdReadClient: 18 POST / HTTP/1.1
D [08/Mar/2012:23:15:16 +0100] cupsdSetBusyState: newbusy="Active clients", busy="Not busy"
D [08/Mar/2012:23:15:16 +0100] cupsdAuthorize: No authentication data provided.
D [08/Mar/2012:23:15:16 +0100] cupsdReadClient: 18 1.1 Get-Jobs 1
D [08/Mar/2012:23:15:16 +0100] Get-Jobs ipp://localhost/
D [08/Mar/2012:23:15:16 +0100] Returning IPP successful-ok for Get-Jobs (ipp://localhost/) from localhost
D [08/Mar/2012:23:15:16 +0100] cupsdSetBusyState: newbusy="Not busy", busy="Active clients"
D [08/Mar/2012:23:15:16 +0100] cupsdReadClient: 18 WAITING Closing on EOF
D [08/Mar/2012:23:15:16 +0100] cupsdCloseClient: 18
D [08/Mar/2012:23:15:16 +0100] cupsdSetBusyState: newbusy="Not busy", busy="Not busy"

Still unsure if this is caused by the same bug or if I should report new one.