AutoTest: Avoid fetching WorkingCopy from multiple threads

Instead fetch it once before starting asynchronous processing and
accept that current state of the WorkingCopy might be not completely
up to date. This avoids a crash that might happen when the code model
tries to update the WorkingCopy while the test code parser fetches
information of the WorkingCopy.

Change-Id: I2a893bc8814090361305657ed3c3d772c7bf07d5
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/plugins/autotest/testcodeparser.cpp

@@ -76,6 +76,7 @@ TestCodeParser::TestCodeParser(TestTreeModel *parent)
             this, [this] (int index) {
         emit testParseResultReady(m_futureWatcher.resultAt(index));
     });
+    connect(this, &TestCodeParser::parsingFinished, this, &TestCodeParser::releaseParserInternals);
 }
 
 TestCodeParser::~TestCodeParser()
@@ -425,5 +426,11 @@ void TestCodeParser::onPartialParsingFinished()
     }
 }
 
+void TestCodeParser::releaseParserInternals()
+{
+    for (ITestParser *parser : m_testCodeParsers)
+        parser->release();
+}
+
 } // namespace Internal
 } // namespace Autotest