Fixed segfault when component creation(mount) throws an error (#13)

Author: Unix4ever

src/imvue.cpp

@@ -371,13 +371,18 @@ namespace ImVue {
   void Component::configure(rapidxml::xml_node<>* node, Context* ctx, ScriptState::Context* sctx, Element* parent)
   {
     Context* child = newChildContext(ctx);
-    child->root = this;
-    if(child->script) {
-      child->script->initialize(mData);
-      child->script->lifecycleCallback(ScriptState::BEFORE_CREATE);
-    }
+    try {
+      child->root = this;
+      if(child->script) {
+        child->script->initialize(mData);
+        child->script->lifecycleCallback(ScriptState::BEFORE_CREATE);
+      }
 
-    mScriptState = ctx->script;
+      mScriptState = ctx->script;
+    } catch(...) {
+      delete child;
+      throw;
+    }
     Element::configure(node, child, sctx, parent);
     if(mConfigured) {
       fireCallback(ScriptState::CREATED);

src/imvue_element.cpp

@@ -516,7 +516,7 @@ namespace ImVue {
 
   void Element::fireCallback(ScriptState::LifecycleCallbackType cb, bool schedule)
   {
-    if(!mCtx->script) {
+    if(!mCtx || !mCtx->script) {
       return;
     }
 

tests/resources/bad.imv

@@ -0,0 +1,18 @@
+<template>
+</template>
+
+<script>
+return {
+  props = {
+    ['value-test'] = {
+      type = ImVue_String,
+      default = 'kek'
+    }
+  },
+  mounted = function()
+    self.crash()
+  end,
+  data = function()
+  end
+}
+</script>

tests/resources/components.xml

@@ -3,7 +3,10 @@
     <button v-on:click="self.count = self.count + 1">increase counter</button>
     <text-unformatted>current count {{ self.count }}</text-unformatted>
   </window>
-  <template v-if="widget == 'basic'">
+  <template v-if="widget == 'bad'">
+    <bad/>
+  </template>
+  <template v-else-if="widget == 'basic'">
     <widget :count="self.count"/>
   </template>
   <template v-else-if="widget == 'lifecycle'">

tests/unit/state.cpp

@@ -679,6 +679,29 @@ TEST_F(LuaScriptStateTest, TestComponentReactivity)
   EXPECT_STREQ(local[0]->text, "updated");
 }
 
+TEST_F(LuaScriptStateTest, TestComponentCreationError)
+{
+  ImVue::LuaScriptState* state = new ImVue::LuaScriptState(L);
+  ImVue::Context* ctx = ImVue::createContext(
+    ImVue::createElementFactory(),
+    state
+  );
+  luaL_dostring(L, "widget = 'bad'");
+  ImVue::Document document(ctx);
+  char* data = ctx->fs->load("components.xml");
+  ASSERT_NE((size_t)data, 0);
+  EXPECT_THROW({
+      try{
+    document.parse(data);
+    renderDocument(document);
+    } catch(ImVue::ElementError e) {
+      std::cout << e.what() << "\n";
+      throw;
+    }
+  }, ImVue::ScriptError);
+  ImGui::MemFree(data);
+}
+
 TEST_F(LuaScriptStateTest, TestComponentLifecycle)
 {
   ImVue::LuaScriptState* state = new ImVue::LuaScriptState(L);