Bug #1386
closedmod_expire overwrites existing Cache-Control headers
Description
When you use mod_expire to set the Expires header, it also writes a Cache-Control header with a max-age attribute. However, that replaces any more detailed Cache-Control header created with mod_setenv. It doesn't seem to matter which module is loaded first - mod_expires still trumps mod_setenv.
Example Configuration:
$HTTP["url"] =~ "\.css$" {
setenv.add-response-header = ( "Cache-Control" => "public, max-age=172000, post-check=172000, pre-check=172000" )
expire.url = ( "" => "access 172000 seconds" )
}
This appears to be because mod_expire uses response_header_overwrite where as mod_setenv uses response_header_insert. However, I'm not sure which is the best fix:
a) Change mod_expire to only insert the header if its missing rather than overwrite it.
b) Change mod_setenv to overwrite headers rather than inserting them.
It depends if mod_setenv not overwriting existing headers should be considered a bug - if so then option b, else option a.
Updated by bonsaikitten about 16 years ago
--- lighttpd-orig/lighttpd-1.4.20/src/mod_expire.c 2008-07-30 21:38:32.000000000 +0200
+++ lighttpd-1.4.20/src/mod_expire.c 2008-11-12 11:41:03.000000000 +0100
@@ -17,6 +17,7 @@
* set 'Expires:' HTTP Headers on demand
*/
+#define response_header_exists(con, key) (NULL != array_get_element(con->response.headers, key))
/* plugin config for all request/connections */
@@ -342,7 +343,9 @@
buffer_copy_string_len(p->expire_tstmp, CONST_STR_LEN("max-age="));
buffer_append_long(p->expire_tstmp, ts);
- response_header_overwrite(srv, con, CONST_STR_LEN("Cache-Control"), CONST_BUF_LEN(p->expire_tstmp));
+ if (!response_header_exists(con, "Cache-Control")) {
+ response_header_overwrite(srv, con, CONST_STR_LEN("Cache-Control"), CONST_BUF_LEN(p->expire_tstmp));
+ }
return HANDLER_GO_ON;
}
This patch fixes the issue for me. It now only overwrites the Cache-Control header if not set by anything else (like mod_setenv )
This behaviour is also more intuitive as it honours the settings from the config file and doesn't magically overwrite them.
Updated by gstrauss over 8 years ago
- Category changed from mod_setenv to mod_expire
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