Hello all,
I'm writing about the benefits of mod_perl in my book, having taken a
CGI script and using ModPerl::Registry turning it into a mod_perl app...
so on so forth... While testing what I'm writing about, I keep seeing
segfaults in my apache log. I started worrying that I have a bug in
DBD::mysql that I need to get fixing that I somehow missed in the fog of
writing a book the past 10 months, but found it had nothing to do with
that at all.
After looking at it in gdb, I noticed it has something to do with
Apache2::RequestRec, the header in particular.
I had a hunch, so I changed:
print $cgi->header('text/html');
To
print "Content-type: text/html\n\n";
Problem goes away. But a new problem manifests itself- the form
parameters aren't showing up properly
I use the line: $vars= $cgi->Vars();
And then access form parameters as $vars->{param}...
Sometimes they submit correctly, other times they don't. I have a couple
GET links and GET parameter parsing seems particularly erratic on
cgi->header() is taken out.
Is there something that I missed in the docs? Are there any particular
issues using CGI.pm with mod_perl that would be worth knowing about? I
will say from the debug output, CGI.pm seems to utilize
Apache2::RequestRec, which I was wondering about.
Also, this makes an interesting issue to include using $cgi->header() in
the book when it causes a segfault.
Note- this segfaulting occurs on two completely different boxes, same
fix applies.
Here's the output of the debugger:
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 47801312445536 (LWP 12196)]
0x00002b79a752c9f6 in XS_Apache2__RequestRec_send_cgi_header
(my_perl=0x1d5c82a0, cv=<value optimized out>)
at Response.xs:149
149 mpxs_Apache2__RequestRec_send_cgi_header(r, buffer);
....
(gdb) bt
#0 0x00002b79a752c9f6 in XS_Apache2__RequestRec_send_cgi_header
(my_perl=0x1d5c82a0,
cv=<value optimized out>) at Response.xs:149
#1 0x0000003971890996 in Perl_pp_entersub ()
from /usr/lib64/perl5/5.8.8/x86_64-linux-thread-multi/CORE/libperl.so
#2 0x000000397188a23e in Perl_runops_standard ()
from /usr/lib64/perl5/5.8.8/x86_64-linux-thread-multi/CORE/libperl.so
#3 0x00000039718375f0 in Perl_call_sv ()
(gdb) frame 0
#0 0x00002b79a752c9f6 in XS_Apache2__RequestRec_send_cgi_header
(my_perl=0x1d5c82a0,
cv=<value optimized out>) at Response.xs:149
149 mpxs_Apache2__RequestRec_send_cgi_header(r, buffer);
(gdb) list
144 Apache2::RequestRec r
145 SV * buffer
146
147
148 CODE:
149 mpxs_Apache2__RequestRec_send_cgi_header(r, buffer);
150
151
152 MODULE = Apache2::Response
153 PROTOTYPES: disabled
