optimize ap_add_common_vars() for the common case where r->subprocess_env is empty

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@92152 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/server/util_script.c b/server/util_script.c
index 669e283183cb33121e49013e5a5fe09df8890509..61d85d902c9c98c872bee08e2963d1318cfe0957 100644 (file)
--- a/server/util_script.c
+++ b/server/util_script.c
@@ -176,8 +176,15 @@ AP_DECLARE(void) ap_add_common_vars(request_rec *r)
 
     /* use a temporary apr_table_t which we'll overlap onto
      * r->subprocess_env later
+     * (exception: if r->subprocess_env is empty at the start,
+     * write directly into it)
      */
-    e = apr_table_make(r->pool, 25 + hdrs_arr->nelts);
+    if (apr_is_empty_table(r->subprocess_env)) {
+      e = r->subprocess_env;
+    }
+    else {
+      e = apr_table_make(r->pool, 25 + hdrs_arr->nelts);
+    }
 
     /* First, add environment vars from headers... this is as per
      * CGI specs, though other sorts of scripting interfaces see
@@ -297,7 +304,9 @@ AP_DECLARE(void) ap_add_common_vars(request_rec *r)
        }
     }
 
-    apr_table_overlap(r->subprocess_env, e, APR_OVERLAP_TABLES_SET);
+    if (e != r->subprocess_env) {
+      apr_table_overlap(r->subprocess_env, e, APR_OVERLAP_TABLES_SET);
+    }
 }
 
 /* This "cute" little function comes about because the path info on