From fb97cbb0d6c94b264752cb645a044974363e642c Mon Sep 17 00:00:00 2001
From: Guoqiang Chen <subchen@gmail.com>
Date: Mon, 1 Dec 2014 02:22:08 +0000
Subject: [PATCH] fixes NPE occured while invoking getTemplate().render(...) in
 functions/methods/tags (#6)

---
 .../jetbrick/template/JetTemplateImpl.java    | 32 ++++++++++++-------
 .../runtime/InterpretContextImpl.java         |  6 +++-
 2 files changed, 26 insertions(+), 12 deletions(-)

diff --git a/jetbrick-template/src/main/java/jetbrick/template/JetTemplateImpl.java b/jetbrick-template/src/main/java/jetbrick/template/JetTemplateImpl.java
index 9a3a79c..d11385e 100644
--- a/jetbrick-template/src/main/java/jetbrick/template/JetTemplateImpl.java
+++ b/jetbrick-template/src/main/java/jetbrick/template/JetTemplateImpl.java
@@ -148,19 +148,29 @@ public void render(Map<String, Object> context, OutputStream out) {
     }
 
     private void doInterpret(Map<String, Object> context, JetWriter writer) {
-        InterpretContextImpl ctx = new InterpretContextImpl(engine, writer, context, securityManager);
+        // 如果在扩展函数，方法，tag 等里面，再次调用 getTemplate().render()，需要保持当前环境，在运行完之后，进行现场恢复
+        // see: https://github.com/subchen/jetbrick-template-2x/issues/6
+        InterpretContextImpl last = (InterpretContextImpl) InterpretContext.current();
         try {
-            ctx.getTemplateStack().push(this);
-            ctx.getValueStack().push(option.getSymbols(), null, true);
-
-            astNode.execute(ctx);
-
-            ctx.getValueStack().pop();
-            ctx.getTemplateStack().pop();
-        } catch (InterpretException e) {
-            throw e.set(ctx.getSource());
+            InterpretContextImpl ctx = new InterpretContextImpl(engine, writer, context, securityManager);
+            try {
+                ctx.getTemplateStack().push(this);
+                ctx.getValueStack().push(option.getSymbols(), null, true);
+
+                astNode.execute(ctx);
+
+                ctx.getValueStack().pop();
+                ctx.getTemplateStack().pop();
+            } catch (InterpretException e) {
+                throw e.set(ctx.getSource());
+            } finally {
+                ctx.freeThreadLocal();
+            }
         } finally {
-            ctx.remove();
+            // 进行现场恢复
+            if (last != null) {
+                last.setThreadLocal();
+            }
         }
     }
 
diff --git a/jetbrick-template/src/main/java/jetbrick/template/runtime/InterpretContextImpl.java b/jetbrick-template/src/main/java/jetbrick/template/runtime/InterpretContextImpl.java
index 19cbfa4..9338b6b 100644
--- a/jetbrick-template/src/main/java/jetbrick/template/runtime/InterpretContextImpl.java
+++ b/jetbrick-template/src/main/java/jetbrick/template/runtime/InterpretContextImpl.java
@@ -45,10 +45,14 @@ public InterpretContextImpl(JetEngine engine, JetWriter writer, Map<String, Obje
         this.valueStack = new ValueStack(engine.getGlobalContext(), context);
         this.writer = writer;
         this.signal = InterpretContext.SIGNAL_NONE;
+        setThreadLocal();
+    }
+
+    public void setThreadLocal() {
         threadLocal.set(this);
     }
 
-    public void remove() {
+    public void freeThreadLocal() {
         threadLocal.remove();
     }