Tcl Library Source Code

with a socket and -translation crlf, if you try to write a buffered puts 
(or gets - not sure which), it will hang if the size is 4095, 8191, ... 
and any multiple of 4096 - 1.

I see this on windows, didn't test linux, problem gone if change crlf to lf

client test script:


######################
set m 8191

set so [socket 127.0.0.1 10042]

chan configure $so -buffering line -encoding utf-8 -blocking 1 -translation crlf
set output [string repeat x   $m]
puts $so  $output                             
set len [gets $so result]
puts "len:$len"
close $so

########### server script run first ########

proc on_accept {so client_ip client_port} {
	set ::so $so
}
set listener [socket -server on_accept -myaddr 127.0.0.1 10042] 
console show
puts "hello"
vwait ::so
puts "after connect"
chan configure $so -buffering line -encoding utf-8 -blocking 1 -translation crlf
set n [gets $so line]

puts "after gets n=$n"
puts $so $line 
puts "after puts of line"
vwait forever

I was also considering that, but then went with pasting the full URL to this ticket to my commit messages. But feel free to create a Tcl ticket, if you think that's better in the long run.

Great catch, my appreciation. We have this bug now for 8 years.

I suppose, it would be helpful for Don to copy this information to a TCL ticket.

Shall I take care ?

Harald

Fixed in
8.6: [https://core.tcl-lang.org/tcl/info/2e8fc36e39984559]
8.7: [https://core.tcl-lang.org/tcl/info/cf8be3fc82dcee22]
9.0: [https://core.tcl-lang.org/tcl/info/658a9d7cb5d6db70]

The bug was introduced by wrong parenthesation in

https://core.tcl-lang.org/tcl/info/d6de6b35d883e546

and not covered by existing tests.

lassign [chan pipe] r w
chan configure $r -buffering line -translation crlf -buffersize 8
chan configure $w -buffering line -translation crlf -buffersize 8
puts $w xxxxxxx
gets $r

write(4, "xxxxxxx\r", 8)                = 8
read(3, "xxxxxxx\r", 8)                 = 8
read(3,