From: Yann Ylavic <ylavic@apache.org>
Date: Thu, 25 Jun 2015 14:50:55 +0000 (+0000)
Subject: mod_substitute: follow up r1684900.
X-Git-Tag: 2.5.0-alpha~3050
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=85fad62c0c025172718ab021f430bda767d64742;p=thirdparty%2Fapache%2Fhttpd.git

mod_substitute: follow up r1684900.
Introduce the SubstituteInheritBefore directive to configure the merge order.
This allows to preserve 2.4 and earlier behaviour.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1687539 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/docs/manual/mod/mod_substitute.xml b/docs/manual/mod/mod_substitute.xml
index 6b7082fe001..4ccc08884a0 100644
--- a/docs/manual/mod/mod_substitute.xml
+++ b/docs/manual/mod/mod_substitute.xml
@@ -162,4 +162,28 @@ Substitute "s|http://internal.blog.example.com/|http://www.example.com/blog/|i"
 </usage>
 </directivesynopsis>
 
+<directivesynopsis>
+<name>SubstituteInheritBefore</name>
+<description>Change the merge order of inherited patterns</description>
+<syntax>SubstituteInheritBefore on|off</syntax>
+<default>SubstituteInheritBefore off</default>
+<contextlist><context>directory</context>
+<context>.htaccess</context></contextlist>
+<override>FileInfo</override>
+<compatibility>Available in httpd 2.4.17 and later</compatibility>
+
+<usage>
+    <p>Whether to apply the inherited <directive>Substitute</directive>
+    patterns first (<code>on</code>), or after the ones of the current
+    context (<code>off</code>).
+    The former was the default in versions 2.4 and earlier, but changed
+    starting with 2.5, hence <directive>SubstituteInheritBefore</directive>
+    set to <code>on</code> allows to restore the legacy behaviour.
+    <directive>SubstituteInheritBefore</directive> is itself inherited,
+    hence contexts that inherit it (those that don't specify their own
+    <directive>SubstituteInheritBefore</directive> value) will apply the
+    closest defined merge order.
+</usage>
+</directivesynopsis>
+
 </modulesynopsis>
diff --git a/modules/filters/mod_substitute.c b/modules/filters/mod_substitute.c
index 22f75dce56e..eb126847de4 100644
--- a/modules/filters/mod_substitute.c
+++ b/modules/filters/mod_substitute.c
@@ -57,6 +57,8 @@ typedef struct {
     apr_array_header_t *patterns;
     apr_size_t max_line_length;
     int max_line_length_set;
+    int inherit_before_set,
+        inherit_before;
 } subst_dir_conf;
 
 typedef struct {
@@ -84,8 +86,17 @@ static void *merge_substitute_dcfg(apr_pool_t *p, void *basev, void *overv)
     subst_dir_conf *base = (subst_dir_conf *) basev;
     subst_dir_conf *over = (subst_dir_conf *) overv;
 
-    a->patterns = apr_array_append(p, base->patterns,
-                                                  over->patterns);
+    if (!over->inherit_before_set) {
+        over->inherit_before = base->inherit_before;
+    }
+    if (over->inherit_before) {
+        a->patterns = apr_array_append(p, base->patterns,
+                                          over->patterns);
+    }
+    else {
+        a->patterns = apr_array_append(p, over->patterns,
+                                          base->patterns);
+    }
     a->max_line_length = over->max_line_length_set ?
                          over->max_line_length : base->max_line_length;
     a->max_line_length_set = over->max_line_length_set ?
@@ -683,6 +694,16 @@ static const char *set_max_line_length(cmd_parms *cmd, void *cfg, const char *ar
     return NULL;
 }
 
+static const char *set_inherit_before(cmd_parms *cmd, void *cfg, int flag)
+{
+    subst_dir_conf *dcfg = (subst_dir_conf *)cfg;
+
+    dcfg->inherit_before = (flag != 0);
+    dcfg->inherit_before_set = 1;
+
+    return NULL;
+}
+
 #define PROTO_FLAGS AP_FILTER_PROTO_CHANGE|AP_FILTER_PROTO_CHANGE_LENGTH
 static void register_hooks(apr_pool_t *pool)
 {
@@ -695,6 +716,8 @@ static const command_rec substitute_cmds[] = {
                   "Pattern to filter the response content (s/foo/bar/[inf])"),
     AP_INIT_TAKE1("SubstituteMaxLineLength", set_max_line_length, NULL, OR_FILEINFO,
                   "Maximum line length"),
+    AP_INIT_FLAG("SubstituteInheritBefore", set_inherit_before, NULL, OR_FILEINFO,
+                 "Apply inherited patterns before those of the current context"),
     {NULL}
 };