Fix exception handling while destructuring

When an exception happens during destructuring, IteratorClose
needs to be called, unless the exception happened inside the
IteratorNext call (in that case the iterator is assumed to be
invalid and we shouldn't call close on it).

Implement this, by ensuring that we set the done return variable
of IteratorNext to true whenever IteratorNext throws an exception.
IteratorClose will check the done state and not do anything in that
case.

Change-Id: I73a27f855f2c4d3134b8cc8980e64bf797d03886
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

2 files changed, 3 insertions, 2 deletions

diff --git a/src/qml/jit/qv4baselinejit.cpp b/src/qml/jit/qv4baselinejit.cpp
index 9e9c586982..d0ac169e4f 100644
--- a/src/qml/jit/qv4baselinejit.cpp
+++ b/src/qml/jit/qv4baselinejit.cpp
@@ -682,7 +682,7 @@ void BaselineJIT::generate_GetIterator(int iterator)
     as->checkException();
 }
 
-void BaselineJIT::generate_IteratorNext(int value)
+void BaselineJIT::generate_IteratorNext(int value, int done)
 {
     as->saveAccumulatorInFrame();
     as->prepareCallWithArgCount(3);
@@ -690,6 +690,7 @@ void BaselineJIT::generate_IteratorNext(int value)
     as->passAccumulatorAsArg(1);
     as->passEngineAsArg(0);
     BASELINEJIT_GENERATE_RUNTIME_CALL(Runtime::method_iteratorNext, CallResultDestination::InAccumulator);
+    as->storeReg(done);
     as->checkException();
 }
 
diff --git a/src/qml/jit/qv4baselinejit_p.h b/src/qml/jit/qv4baselinejit_p.h
index 972e9d07b7..7e3fcfa5e6 100644
--- a/src/qml/jit/qv4baselinejit_p.h
+++ b/src/qml/jit/qv4baselinejit_p.h
@@ -148,7 +148,7 @@ public:
     void generate_PopScriptContext() override;
     void generate_PopContext() override;
     void generate_GetIterator(int iterator) override;
-    void generate_IteratorNext(int value) override;
+    void generate_IteratorNext(int value, int done) override;
     void generate_IteratorClose(int done) override;
     void generate_DestructureRestElement() override;
     void generate_DeleteProperty(int base, int index) override;