This happens running under mod_perl2 using Apache2::Request to process a submitted form that has <input type="file" ...> when the user does not specify a file. It looks like execution of the perl code abruptly ends at the call to ->upload(). No error is written to the error log, but the browser gets a response with content up until that call.
I have built a minimal handler to demonstrate this. You can try it at
http://backdev.nber.org/uploadtest
To see the bug, select a file for the first field but not the second.
This is called with the following simple Apache config:
PerlModule NBER::UploadDebug::UploadTest <Location "/uploadtest"> SetHandler perl-script PerlResponseHandler NBER::UploadDebug::UploadTest </Location>
package NBER::UploadDebug::UploadTest;
use Apache2::Request;
use Apache2::RequestUtil;
use Apache2::Upload;
sub handler {
my $r = shift;
$r->content_type("text/html; charset=utf-8");
if ($r->method eq 'POST') {
print "<html><body><h1>Form submitted</h1><pre>\n";
print "About to get Apache2::Request->new\n";
$req = Apache2::Request->new($r,
TEMP_DIR => '/tmp');
my @params = $req->param();
print "all params: " . join(",",@params) . "\n";
my @filefieldnames = ('file1','file2');
print "filefieldnames:" . join(",",@filefieldnames) . "\n";
foreach my $n (@filefieldnames) {
print "About to check param $n\n";
next unless $req->param($n);
print "About to call upload on $n\n";
my $fref = $req->upload($n);
print "filename for $n: " . $fref->filename() ."\n";
}
print "after names loop\n";
} else {
print qq[
<html>
<body>
<h1>This is the form</h1>
<br>
<form name="theform" method="POST" enctype="multipart/form-data">
file1:
<input type="file" name="file1">
<br>
file2:
<input type="file" name="file2">
<br>
<input type="submit" value="submit">
</form>
</body>
</html>
];
}
return Apache2::Const::OK;
}
sub new {
my $proto = shift;
my $class = ref($proto) || $proto;
bless $self, $class;
}
1;
The bug is not triggered on our production web server, which is running:
FreeBSD bsdtest 13.2-RELEASE-p4 FreeBSD 13.2-RELEASE-p4 GENERIC amd64 apache24-2.4.53_1 apr-1.7.3.1.6.3_1 libapreq2-2.13_5 p5-libapreq2-2.16 ap24-mod_perl2-2.0.12,3
The bug is triggered on a fairly recent FreeBSD with up to date packages, but also on
FreeBSD bsdtestbug 13.2-RELEASE-p4 FreeBSD 13.2-RELEASE-p4 GENERIC amd64 apache24-2.4.58_1 apr-1.7.3.1.6.3_1 libapreq2-2.17 p5-libapreq2-2.16 ap24-mod_perl2-2.0.12,3