Fix crashes when parsing functions with no parameters

Commit da5fffbd34d8be68f8ee4c649881dbb673c9c0a5 introduced deferencing
of the formals parameter list that can be a null pointer if the declared
function has no parameters.

Change-Id: Id7dce0f78b16266e672f0ae430ee4f979de5734d
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

4 files changed, 8 insertions, 8 deletions

diff --git a/src/qml/compiler/qqmlirbuilder.cpp b/src/qml/compiler/qqmlirbuilder.cpp
index 9de27a2588..f763e55113 100644
--- a/src/qml/compiler/qqmlirbuilder.cpp
+++ b/src/qml/compiler/qqmlirbuilder.cpp
@@ -983,7 +983,7 @@ bool IRBuilder::visit(QQmlJS::AST::UiSourceElement *node)
         f->index = index;
         f->nameIndex = registerString(funDecl->name.toString());
 
-        const QStringList formals = funDecl->formals->formals();
+        const QStringList formals = funDecl->formals ? funDecl->formals->formals() : QStringList();
         int formalsCount = formals.size();
         f->formals.allocate(pool, formalsCount);
 
diff --git a/src/qml/compiler/qv4codegen.cpp b/src/qml/compiler/qv4codegen.cpp
index 0a46fc7a8e..4e6d56adcf 100644
--- a/src/qml/compiler/qv4codegen.cpp
+++ b/src/qml/compiler/qv4codegen.cpp
@@ -2425,7 +2425,7 @@ int Codegen::defineFunction(const QString &name, AST::Node *ast,
         }
     }
     if (_context->usesArgumentsObject == Context::ArgumentsObjectUsed) {
-        if (_context->isStrict || !formals->isSimpleParameterList()) {
+        if (_context->isStrict || (formals && !formals->isSimpleParameterList())) {
             Instruction::CreateUnmappedArgumentsObject setup;
             bytecodeGenerator->addInstruction(setup);
         } else {
diff --git a/src/qml/compiler/qv4compilercontext_p.h b/src/qml/compiler/qv4compilercontext_p.h
index e53fb26e4a..2479465587 100644
--- a/src/qml/compiler/qv4compilercontext_p.h
+++ b/src/qml/compiler/qv4compilercontext_p.h
@@ -265,7 +265,7 @@ struct Context {
             return true;
 
         if (type != FunctionDefinition) {
-            if (formals->containsName(name))
+            if (formals && formals->containsName(name))
                 return (scope == QQmlJS::AST::VariableScope::Var);
         }
         MemberMap::iterator it = members.find(name);
diff --git a/src/qml/compiler/qv4compilerscanfunctions.cpp b/src/qml/compiler/qv4compilerscanfunctions.cpp
index c6e792fc45..3bbef3a96a 100644
--- a/src/qml/compiler/qv4compilerscanfunctions.cpp
+++ b/src/qml/compiler/qv4compilerscanfunctions.cpp
@@ -420,7 +420,7 @@ bool ScanFunctions::enterFunction(Node *ast, const QString &name, FormalParamete
             outerContext->usesArgumentsObject = Context::ArgumentsObjectNotUsed;
     }
 
-    if (formals->containsName(QStringLiteral("arguments")))
+    if (formals && formals->containsName(QStringLiteral("arguments")))
         _context->usesArgumentsObject = Context::ArgumentsObjectNotUsed;
     if (expr) {
         if (expr->isArrowFunction)
@@ -430,18 +430,18 @@ bool ScanFunctions::enterFunction(Node *ast, const QString &name, FormalParamete
     }
 
 
-    if (!name.isEmpty() && !formals->containsName(name))
+    if (!name.isEmpty() && (!formals || !formals->containsName(name)))
         _context->addLocalVar(name, Context::ThisFunctionName, VariableScope::Var);
     _context->formals = formals;
 
     if (body && !_context->isStrict)
         checkDirectivePrologue(body);
 
-    bool isSimpleParameterList = formals->isSimpleParameterList();
+    bool isSimpleParameterList = formals && formals->isSimpleParameterList();
 
-    _context->arguments = formals->formals();
+    _context->arguments = formals ? formals->formals() : QStringList();
 
-    const QStringList boundNames = formals->boundNames();
+    const QStringList boundNames = formals ? formals->boundNames() : QStringList();
     for (int i = 0; i < boundNames.size(); ++i) {
         const QString &arg = boundNames.at(i);
         if (_context->isStrict || !isSimpleParameterList) {