Core: improved ngx_reset_pool() (ticket #490). Previously pool->current wasn't moved back to pool, resulting in blocks not used for further allocations if pool->current was already moved at the time of ngx_reset_pool(). Additionally, to preserve logic of moving pool->current, the p->d.failed counters are now properly cleared. While here, pool->chain is also cleared. This change is essentially a nop with current code, but generally improves things.

--- a/src/core/ngx_palloc.c
+++ b/src/core/ngx_palloc.c
@@ -105,11 +105,14 @@ ngx_reset_pool(ngx_pool_t *pool)
         }
     }
 
-    pool->large = NULL;
-
     for (p = pool; p; p = p->d.next) {
         p->d.last = (u_char *) p + sizeof(ngx_pool_t);
+        p->d.failed = 0;
     }
+
+    pool->current = pool;
+    pool->chain = NULL;
+    pool->large = NULL;
 }