From: Dmitry Volyntsev <xeioex@nginx.com>
Date: Tue, 17 Jul 2018 17:25:47 +0000 (+0300)
Subject: Fixed exception handling in njs_vm_value_to_ext_string().
X-Git-Tag: 0.2.3~16
X-Git-Url: http://git.kaiwu.me/sitemap.xml?a=commitdiff_plain;h=8e20d5db9809bd071a335647ecfd2a1f7e2cf63c;p=njs.git

Fixed exception handling in njs_vm_value_to_ext_string().
---

diff --git a/njs/njs_vm.c b/njs/njs_vm.c
index ec4fe2ea..bf2e7fc3 100644
--- a/njs/njs_vm.c
+++ b/njs/njs_vm.c
@@ -3273,8 +3273,9 @@ fail:
 static njs_ret_t
 njs_object_value_to_string(njs_vm_t *vm, njs_value_t *value)
 {
-    u_char     *current;
-    njs_ret_t  ret;
+    u_char              *current;
+    njs_ret_t           ret;
+    njs_native_frame_t  *previous;
 
     static const njs_vmcode_1addr_t  value_to_string[] = {
         { .code = { .operation = njs_vmcode_value_to_string,
@@ -3298,6 +3299,14 @@ njs_object_value_to_string(njs_vm_t *vm, njs_value_t *value)
     njs_set_invalid(&vm->top_frame->trap_scratch);
     vm->top_frame->trap_values[0] = *value;
 
+    /*
+     * Prevent njs_vmcode_interpreter() to unwind the current frame if
+     * an exception happens.  It preserves the current frame state if
+     * njs_vm_value_to_ext_string() is called from within njs_vm_run().
+     */
+    previous = vm->top_frame->previous;
+    vm->top_frame->previous = NULL;
+
     ret = njs_vmcode_interpreter(vm);
 
     if (ret == NJS_STOP) {
@@ -3306,6 +3315,7 @@ njs_object_value_to_string(njs_vm_t *vm, njs_value_t *value)
     }
 
     vm->current = current;
+    vm->top_frame->previous = previous;
 
     return ret;
 }
diff --git a/njs/test/njs_expect_test.exp b/njs/test/njs_expect_test.exp
index 81150a02..5247c7c6 100644
--- a/njs/test/njs_expect_test.exp
+++ b/njs/test/njs_expect_test.exp
@@ -203,6 +203,13 @@ njs_test {
      "JSON.parse(Error()\r\nSyntaxError: Unexpected token \"\" in 1"}
 }
 
+njs_test {
+    {"try { console.log({ toString: function() { throw 'test'; } }) } catch (e) {}\r\n"
+     "undefined"}
+    {"function f() { throw 't' }; try { console.log({ toString: function() { return f() } }) } catch (e) {}\r\n"
+     "undefined"}
+}
+
 # Non-ASCII characters
 njs_test {
     {"'絵文字'\r\n"