now we prohibit use of true jump argument in ngx.req.set_uri() in contexts other than rewrite_by_lua and rewrite_by_lua_file. a lua exception will be thrown if the context is incorrect.

README

@@ -1138,6 +1138,10 @@ Nginx API for Lua
 
         ngx.req.set_uri("/foo")
 
+    The "jump" can only be set to "true" in rewrite_by_lua and
+    rewrite_by_lua_file. Use of jump in other contexts is prohibited and
+    will throw out a Lua exception.
+
     A more sophisticated example involving regex substitutions is as follows
 
         location /test {

README.markdown

@@ -1232,6 +1232,8 @@ or equivalently,
     ngx.req.set_uri("/foo")
 
 
+The `jump` can only be set to `true` in [rewrite_by_lua](http://wiki.nginx.org/HttpLuaModule#rewrite_by_lua) and [rewrite_by_lua_file](http://wiki.nginx.org/HttpLuaModule#rewrite_by_lua_file). Use of jump in other contexts is prohibited and will throw out a Lua exception.
+
 A more sophisticated example involving regex substitutions is as follows
 
 

doc/HttpLuaModule.wiki

@@ -1197,6 +1197,8 @@ or equivalently,
     ngx.req.set_uri("/foo")
 </geshi>
 
+The <code>jump</code> can only be set to <code>true</code> in [[#rewrite_by_lua|rewrite_by_lua]] and [[#rewrite_by_lua_file|rewrite_by_lua_file]]. Use of jump in other contexts is prohibited and will throw out a Lua exception.
+
 A more sophisticated example involving regex substitutions is as follows
 
 <geshi lang="nginx">

src/ngx_http_lua_args.c

@@ -23,6 +23,7 @@ ngx_http_lua_ngx_req_set_uri(lua_State *L) {
     u_char                      *p;
     int                          n;
     int                          jump = 0;
+    ngx_http_lua_ctx_t          *ctx;
 
     n = lua_gettop(L);
 
@@ -60,9 +61,29 @@ ngx_http_lua_ngx_req_set_uri(lua_State *L) {
     ngx_http_set_exten(r);
 
     if (jump) {
-        r->uri_changed = 1;
 
-        return lua_yield(L, 0);
+        ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
+
+#if defined(DDEBUG) && DDEBUG
+        if (ctx) {
+            dd("rewrite: %d, access: %d, content: %d",
+                    (int) ctx->entered_rewrite_phase,
+                    (int) ctx->entered_access_phase,
+                    (int) ctx->entered_content_phase);
+        }
+#endif
+
+        if (ctx && ctx->entered_rewrite_phase
+            && !ctx->entered_access_phase
+            && !ctx->entered_content_phase)
+        {
+            r->uri_changed = 1;
+            return lua_yield(L, 0);
+        }
+
+        return luaL_error(L, "attempt to call ngx.req.set_uri to do "
+                "location jump in contexts other than rewrite_by_lua and "
+                "rewrite_by_lua_file");
     }
 
     r->valid_location = 0;

t/030-uri-args.t

@@ -17,7 +17,7 @@ no_root_location();
 $ENV{TEST_NGINX_CLIENT_PORT} ||= $ENV{TEST_NGINX} ||= server_port();
 
 #no_diff();
-#no_long_string();
+no_long_string();
 run_tests();
 
 __DATA__
@@ -504,3 +504,122 @@ HTTP/1.0 ca%20t=%25
 --- response_body
 hello
 
+
+
+=== TEST 20: ngx.req.set_uri with jump not allowed in access phase
+--- config
+    location /bar {
+        echo $query_string;
+    }
+    location /foo {
+        #set $args 'hello';
+        set $err '';
+        access_by_lua '
+            res, err = pcall(ngx.req.set_uri, "/bar", true);
+            ngx.var.err = err
+        ';
+        echo "err: $err";
+    }
+--- request
+    GET /foo?world
+--- response_body
+err: attempt to call ngx.req.set_uri to do location jump in contexts other than rewrite_by_lua and rewrite_by_lua_file
+
+
+
+=== TEST 21: ngx.req.set_uri without jump allowed in access phase
+--- config
+    location /bar {
+        echo $query_string;
+    }
+    location /foo {
+        #set $args 'hello';
+        set $err '';
+        access_by_lua '
+            ngx.req.set_uri("/bar")
+        ';
+        echo "uri: $uri";
+    }
+--- request
+    GET /foo?world
+--- response_body
+uri: /bar
+
+
+
+=== TEST 22: ngx.req.set_uri with jump not allowed in content phase
+--- config
+    location /bar {
+        echo $query_string;
+    }
+    location /foo {
+        #set $args 'hello';
+        content_by_lua '
+            res, err = pcall(ngx.req.set_uri, "/bar", true);
+            ngx.say("err: ", err)
+        ';
+    }
+--- request
+    GET /foo?world
+--- response_body
+err: attempt to call ngx.req.set_uri to do location jump in contexts other than rewrite_by_lua and rewrite_by_lua_file
+
+
+
+=== TEST 23: ngx.req.set_uri without jump allowed in content phase
+--- config
+    location /bar {
+        echo $query_string;
+    }
+    location /foo {
+        #set $args 'hello';
+        set $err '';
+        content_by_lua '
+            ngx.req.set_uri("/bar")
+            ngx.say("uri: ", ngx.var.uri)
+        ';
+    }
+--- request
+    GET /foo?world
+--- response_body
+uri: /bar
+
+
+
+=== TEST 24: ngx.req.set_uri with jump not allowed in set_by_lua
+--- config
+    location /bar {
+        echo $query_string;
+    }
+    location /foo {
+        #set $args 'hello';
+        set_by_lua $err '
+            res, err = pcall(ngx.req.set_uri, "/bar", true);
+            return err
+        ';
+        echo "err: $err";
+    }
+--- request
+    GET /foo?world
+--- response_body
+err: attempt to call ngx.req.set_uri to do location jump in contexts other than rewrite_by_lua and rewrite_by_lua_file
+
+
+
+=== TEST 25: ngx.req.set_uri without jump is allowed in set_by_lua
+--- config
+    location /bar {
+        echo $query_string;
+    }
+    location /foo {
+        set_by_lua $dummy '
+            ngx.req.set_uri("/bar")
+            return ""
+        ';
+        echo "uri: $uri";
+    }
+--- request
+    GET /foo?world
+--- response_body
+uri: /bar
+