ngx_http_upstream_create() to cleanup the previous upstream after internal redirect

diff --git a/src/http/modules/ngx_http_fastcgi_module.c b/src/http/modules/ngx_http_fastcgi_module.c
index 36b34a0..1855e3c 100644
--- a/src/http/modules/ngx_http_fastcgi_module.c
+++ b/src/http/modules/ngx_http_fastcgi_module.c

@@ -543,19 +543,16 @@
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
     }
 
-    f = ngx_pcalloc(r->pool, sizeof(ngx_http_fastcgi_ctx_t));
-    if (f == NULL) {
-        return NGX_ERROR;
-    }
-
-    ngx_http_set_ctx(r, f, ngx_http_fastcgi_module);
-
-    u = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_t));
-    if (u == NULL) {
+    if (ngx_http_upstream_create(r) != NGX_OK) {
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
     }
 
-    r->upstream = u;
+    f = ngx_pcalloc(r->pool, sizeof(ngx_http_fastcgi_ctx_t));
+    if (f == NULL) {
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    ngx_http_set_ctx(r, f, ngx_http_fastcgi_module);
 
     flcf = ngx_http_get_module_loc_conf(r, ngx_http_fastcgi_module);
 
@@ -565,15 +562,11 @@
         }
     }
 
+    u = r->upstream;
+
     u->schema.len = sizeof("fastcgi://") - 1;
     u->schema.data = (u_char *) "fastcgi://";
 
-    u->peer.log = r->connection->log;
-    u->peer.log_error = NGX_ERROR_ERR;
-#if (NGX_THREADS)
-    u->peer.lock = &r->connection->lock;
-#endif
-
     u->output.tag = (ngx_buf_tag_t) &ngx_http_fastcgi_module;
 
     u->conf = &flcf->upstream;

diff --git a/src/http/modules/ngx_http_memcached_module.c b/src/http/modules/ngx_http_memcached_module.c
index e613a20..dc7c767 100644
--- a/src/http/modules/ngx_http_memcached_module.c
+++ b/src/http/modules/ngx_http_memcached_module.c

@@ -176,24 +176,19 @@
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
     }
 
-    mlcf = ngx_http_get_module_loc_conf(r, ngx_http_memcached_module);
-
-    u = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_t));
-    if (u == NULL) {
+    if (ngx_http_upstream_create(r) != NGX_OK) {
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
     }
 
+    u = r->upstream;
+
     u->schema.len = sizeof("memcached://") - 1;
     u->schema.data = (u_char *) "memcached://";
 
-    u->peer.log = r->connection->log;
-    u->peer.log_error = NGX_ERROR_ERR;
-#if (NGX_THREADS)
-    u->peer.lock = &r->connection->lock;
-#endif
-
     u->output.tag = (ngx_buf_tag_t) &ngx_http_memcached_module;
 
+    mlcf = ngx_http_get_module_loc_conf(r, ngx_http_memcached_module);
+
     u->conf = &mlcf->upstream;
 
     u->create_request = ngx_http_memcached_create_request;
@@ -202,8 +197,6 @@
     u->abort_request = ngx_http_memcached_abort_request;
     u->finalize_request = ngx_http_memcached_finalize_request;
 
-    r->upstream = u;
-
     ctx = ngx_palloc(r->pool, sizeof(ngx_http_memcached_ctx_t));
     if (ctx == NULL) {
         return NGX_HTTP_INTERNAL_SERVER_ERROR;

diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index 0a512f5..88530e1 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c

@@ -590,13 +590,10 @@
     ngx_http_proxy_ctx_t       *ctx;
     ngx_http_proxy_loc_conf_t  *plcf;
 
-    u = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_t));
-    if (u == NULL) {
+    if (ngx_http_upstream_create(r) != NGX_OK) {
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
     }
 
-    r->upstream = u;
-
     ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_proxy_ctx_t));
     if (ctx == NULL) {
         return NGX_ERROR;
@@ -606,6 +603,8 @@
 
     plcf = ngx_http_get_module_loc_conf(r, ngx_http_proxy_module);
 
+    u = r->upstream;
+
     if (plcf->proxy_lengths == 0) {
         ctx->vars = plcf->vars;
         u->schema = plcf->vars.schema;
@@ -619,12 +618,6 @@
         }
     }
 
-    u->peer.log = r->connection->log;
-    u->peer.log_error = NGX_ERROR_ERR;
-#if (NGX_THREADS)
-    u->peer.lock = &r->connection->lock;
-#endif
-
     u->output.tag = (ngx_buf_tag_t) &ngx_http_proxy_module;
 
     u->conf = &plcf->upstream;

diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index a8cf07f..23cf1b6 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c

@@ -348,6 +348,35 @@
 };
 
 
+ngx_int_t
+ngx_http_upstream_create(ngx_http_request_t *r)
+{
+    ngx_http_upstream_t  *u;
+
+    u = r->upstream;
+
+    if (u && u->cleanup) {
+        ngx_http_upstream_cleanup(r);
+        *u->cleanup = NULL;
+    }
+
+    u = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_t));
+    if (u == NULL) {
+        return NGX_ERROR;
+    }
+
+    r->upstream = u;
+
+    u->peer.log = r->connection->log;
+    u->peer.log_error = NGX_ERROR_ERR;
+#if (NGX_THREADS)
+    u->peer.lock = &r->connection->lock;
+#endif
+
+    return NGX_OK;
+}
+
+
 void
 ngx_http_upstream_init(ngx_http_request_t *r)
 {

diff --git a/src/http/ngx_http_upstream.h b/src/http/ngx_http_upstream.h
index fc77767..ac2682d 100644
--- a/src/http/ngx_http_upstream.h
+++ b/src/http/ngx_http_upstream.h

@@ -317,6 +317,7 @@
 ngx_int_t ngx_http_upstream_header_variable(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data);
 
+ngx_int_t ngx_http_upstream_create(ngx_http_request_t *r);
 void ngx_http_upstream_init(ngx_http_request_t *r);
 ngx_http_upstream_srv_conf_t *ngx_http_upstream_add(ngx_conf_t *cf,
     ngx_url_t *u, ngx_uint_t flags);