resolve #126 [rt.cpan.org #89827] - fix url PATH_INFO

substitution logic to not remove PATH_INFO if it is the same as
SCRIPT_NAME as some webservers (IIS) sometimes set PATH_INFO to
the same value as SCRIPT_NAME

Changes

@@ -8,6 +8,10 @@
       charset force numeric encoding of all characters, because that does not
       happen
 
+    [ SPEC / BUG FIXES ]
+    - don't sub out PATH_INFO in url if PATH_INFO is the same as SCRIPT_NAME
+      (RT #89827)
+
 4.07 2014-10-12
 
     [ RELEASE NOTES ]

lib/CGI.pm

@@ -2947,7 +2947,13 @@ sub url {
 
     my $uri         =  $rewrite && $request_uri ? $request_uri : $script_name;
     $uri            =~ s/\?.*$//s; # remove query string
-    $uri            =~ s/\Q$ENV{PATH_INFO}\E$// if defined $ENV{PATH_INFO};
+
+	if ( defined( $ENV{PATH_INFO} ) ) {
+		# IIS sometimes sets PATH_INFO to the same value as SCRIPT_NAME so only sub it out
+		# if SCRIPT_NAME isn't defined or isn't the same value as PATH_INFO
+    	$uri =~ s/\Q$ENV{PATH_INFO}\E$//
+			if ( ! defined( $ENV{SCRIPT_NAME} ) or $ENV{PATH_INFO} ne $ENV{SCRIPT_NAME} );
+	}
 
     if ($full) {
         my $protocol = $self->protocol();

t/url.t

@@ -84,6 +84,15 @@ subtest 'RT#58377: + in PATH_INFO' => sub {
     is($q->path_info(), '/hello+world', 'a plus sign in a script name is preserved when calling path_info()');
 };
 
+subtest 'IIS PATH_INFO eq SCRIPT_NAME' => sub {
+    local $ENV{PATH_INFO}           = '/hello+world';
+    local $ENV{HTTP_X_FORWARDED_HOST} = undef;
+    local $ENV{HTTP_HOST}           = 'example.com';
+    local $ENV{SCRIPT_NAME}         = '/hello+world';
+
+    my $q = CGI->new;
+    is( $q->url,'http://example.com/hello+world','PATH_INFO being the same as SCRIPT_NAME');
+};
 
 done_testing();