Fix bug #79329 - get_headers should not accept \0

(cherry picked from commit 69fdc14)

Author: smalyshev

NEWS

@@ -44,6 +44,8 @@ PHP                                                                        NEWS
   . Fixed bug #79294 (::columnType() may fail after SQLite3Stmt::reset()). (cmb)
 
 - Standard:
+  . Fixed bug #79329 (get_headers() silently truncates after a null byte). 
+    (CVE-2020-7066) (cmb)
   . Fixed bug #79254 (getenv() w/o arguments not showing changes). (cmb)
   . Fixed bug #79265 (Improper injection of Host header when using fopen for
     http requests). (Miguel Xavier Penha Neto)

ext/standard/url.c

@@ -672,7 +672,7 @@ PHP_FUNCTION(get_headers)
 	php_stream_context *context;
 
 	ZEND_PARSE_PARAMETERS_START(1, 3)
-		Z_PARAM_STRING(url, url_len)
+		Z_PARAM_PATH(url, url_len)
 		Z_PARAM_OPTIONAL
 		Z_PARAM_LONG(format)
 		Z_PARAM_RESOURCE_EX(zcontext, 1, 0)