multi/single.tcl segfaults

[wusspuss]

#0  0x0000555555663410 in ?? ()
#1  0x00007ffff77539ba in curl_multi_info_read () from /usr/lib/libcurl.so.4
#2  0x00007ffff7b06175 in curlMultiGetInfo (interp=0x55555556a9a0, 
    curlMultiHandlePtr=0x5555556e6860) at ./generic/multi.c:389
#3  0x00007ffff7b05e1f in curlMultiObjCmd (clientData=0x5555556aadf0, 
    interp=0x55555556a9a0, objc=2, objv=0x5555555786c0)
    at ./generic/multi.c:187
#4  0x00007ffff7e3a7e9 in TclNRRunCallbacks (
    interp=interp@entry=0x55555556a9a0, result=0, rootPtr=0x0)
    at /usr/src/debug/tcl/tcl8.6.16/generic/tclBasic.c:4541
#5  0x00007ffff7e3a874 in Tcl_EvalObjv (interp=interp@entry=0x55555556a9a0, 
    objc=objc@entry=2, objv=objv@entry=0x5555555786c0, 
    flags=flags@entry=2097168)
    at /usr/src/debug/tcl/tcl8.6.16/generic/tclBasic.c:4260
#6  0x00007ffff7e3c974 in TclEvalEx (interp=interp@entry=0x55555556a9a0, 
    script=0x5555555c2ee1 "$curlMultiHandle getinfo]\"\n\nputs -nonewline \"Removing the easy handle: \"\nputs [$curlMultiHandle removehandle $curlEasyHandle]\n\nputs -nonewline \"Cleanup the multi handle handle: \"\nputs [$curlMultiHandl"..., numBytes=<optimized out>, flags=flags@entry=0, line=42, 
    clNextOuter=<optimized out>, 
    outerScript=0x5555555c2b40 "package require TclCurl\n\nproc Perform {multiHandle} {\n    if {[catch {$multiHandle active} activeTransfers]} {\n        puts \"Error checking active transfers: $activeTransfers\"\n        return -1\n    }\--T--Type <RET> for m--Type <RET>--Type <R--Type <R--T--T--T--Type--Type--T--T--T--T--Type--Type--Type--T--T--T--T--T--T--T--T--T--Type <RET--Type <RET> for more, q to quit, c to continue without paging--c
n"...) at /usr/src/debug/tcl/tcl8.6.16/generic/tclBasic.c:5409
#7  0x00007ffff7f15df8 in TclSubstTokens (interp=interp@entry=0x55555556a9a0, tokenPtr=<optimized out>, tokenPtr@entry=0x555555578098, count=1, tokensLeftPtr=tokensLeftPtr@entry=0x0, 
    line=<optimized out>, line@entry=42, clNextOuter=<optimized out>, clNextOuter@entry=0x0, 
    outerScript=0x5555555c2b40 "package require TclCurl\n\nproc Perform {multiHandle} {\n    if {[catch {$multiHandle active} activeTransfers]} {\n        puts \"Error checking active transfers: $activeTransfers\"\n        return -1\n    }\n"...) at /usr/src/debug/tcl/tcl8.6.16/generic/tclParse.c:2298
#8  0x00007ffff7e3c82d in TclEvalEx (interp=interp@entry=0x55555556a9a0, 
    script=0x5555555c2b40 "package require TclCurl\n\nproc Perform {multiHandle} {\n    if {[catch {$multiHandle active} activeTransfers]} {\n        puts \"Error checking active transfers: $activeTransfers\"\n        return -1\n    }\n"..., numBytes=<optimized out>, flags=flags@entry=0, line=42, line@entry=1, clNextOuter=clNextOuter@entry=0x0, 
    outerScript=0x5555555c2b40 "package require TclCurl\n\nproc Perform {multiHandle} {\n    if {[catch {$multiHandle active} activeTransfers]} {\n        puts \"Error checking active transfers: $activeTransfers\"\n        return -1\n    }\n"...) at /usr/src/debug/tcl/tcl8.6.16/generic/tclBasic.c:5297
#9  0x00007ffff7f00553 in Tcl_FSEvalFileEx (interp=interp@entry=0x55555556a9a0, pathPtr=pathPtr@entry=0x5555555a7260, encodingName=<optimized out>)
    at /usr/src/debug/tcl/tcl8.6.16/generic/tclIOUtil.c:1827
#10 0x00007ffff7f08ca5 in Tcl_MainEx (argc=<optimized out>, argc@entry=2, argv=argv@entry=0x7fffffffe4f8, appInitProc=appInitProc@entry=0x555555555160 <Tcl_AppInit>, interp=0x55555556a9a0)
    at /usr/src/debug/tcl/tcl8.6.16/generic/tclMain.c:403
#11 0x000055555555504b in main (argc=2, argv=0x7fffffffe4f8) at /usr/src/debug/tcl/tcl8.6.16/unix/tclAppInit.c:91

I did build tclcurl-fa with --enable-symbols so not sure where that ?? could be coming from. I get this error on archlinux, both with tclcurl built locally and with kitcreator's tclkits.

curl 8.11.1-3
tcl 8.6.16-1

[bovine]

This is using the unmodified version of the tests/multi/single.tcl script? Do you have a webserver running locally that can serve http://127.0.0.1/index.html?

Is this with the current master branch, or the another released version of this repo?

Does this package work for you otherwise in your development work?

[wusspuss]

This is using the unmodified version of the tests/multi/single.tcl script?

Yes.

Do you have a webserver running locally that can serve http://127.0.0.1/index.html?

Yes, but it segfauls with and without a server, it segfaults if I give it a remote url too

Is this with the current master branch

Yes.

Does this package work for you otherwise in your development work?

No. This is the first time I tried the package - I discovered it segfaulting in my code first.

My own example to make it segfault:

package require TclCurl
set m [curl::multiinit]
set h [curl::init]

$h configure -url https://api.ipify.org?format=json
$m addhandle $h
# $m methods work fine until you call $m perform
puts "active: [$m getinfo]"

while {1} {
    set r [$m perform]
    if {$r<=0} {
	break
    }
}
# the $h methods don't segfault
puts "code: [$h getinfo httpcode]"
# $m active doesn't segfault
puts "active: [$m active]"
# This will segfault
puts [$m getinfo]
# So will seemingly any other method of $m, like
$m removehandle $h

Also I poked around with the C code a bit - I made it print the output of curl_multi_get_handles before removing the handle - it turned out empty after you call perform. I'm not too familiar with curl, but afaik that's not how that's supposed to be, the handle is supposed to be manually removed.

[bovine]

We do have another ticket #12 that points out other issues with this test file, which might actually be the same underlying issue.