http/cgi: clean up environment.
clean up duplicate environment for CGI.
overriding former by latter.
On windows, When there are duplicated environments like following,
SCRIPT_FILENAME=c:/progra~1/php/php-cgi.exe
SCRIPT_FILENAME=/foo.php
CreateProcess use first entry.
If make cgi.Handle like following,
cgih = cgi.Handler{
Path: "c:/strawberry/perl/bin/perl.exe",
Dir: "c:/path/to/webroot",
Root: "c:/path/to/webroot",
Args: []string{"foo.php"},
Env: []string{"SCRIPT_FILENAME=foo.php"},
}
http/cgi should behave "SCRIPT_FILENAME is foo.php".
But currently, http/cgi is set duplicate environment entries.
So, browser show binary dump of "php-cgi.exe" that is specified indented
SCRIPT_FILENAME in first entry.
This change clean up duplicates, and use latters.
R=golang-dev, bradfitz, bradfitz
CC=golang-dev
https://golang.org/cl/
5010044