Fix style parsing bug for constant expressions

include/mbgl/style/conversion/data_driven_property_value.hpp

@@ -44,8 +44,6 @@ struct Converter<DataDrivenPropertyValue<T>> {
             } else if (!featureConstant && !zoomConstant) {
                 return DataDrivenPropertyValue<T>(CompositeFunction<T>(std::move(*expression)));
             } else {
-                // If an expression is neither zoom- nor feature-dependent, it
-                // should have been reduced to a Literal when it was parsed.
                 auto literal = dynamic_cast<Literal*>(expression->get());
                 assert(literal);
                 optional<T> constant = fromExpressionValue<T>(literal->getValue());

include/mbgl/style/expression/let.hpp

@@ -70,6 +70,9 @@ class Var : public Expression {
 
     mbgl::Value serialize() const override;
     std::string getOperator() const override { return "var"; }
+
+    const std::shared_ptr<Expression>& getBoundExpression() const { return value; }
+
 private:
     std::string name;
     std::shared_ptr<Expression> value;

platform/node/test/ignores.json

@@ -1,6 +1,8 @@
 {
   "query-tests/circle-pitch-scale/viewport-inside-align-map": "https://github.com/mapbox/mapbox-gl-native/issues/10615",
   "query-tests/circle-pitch-scale/viewport-inside-align-viewport": "https://github.com/mapbox/mapbox-gl-native/issues/10615",
+  "query-tests/edge-cases/box-cutting-antimeridian-z0": "https://github.com/mapbox/mapbox-gl-native/issues/11607",
+  "query-tests/edge-cases/null-island": "https://github.com/mapbox/mapbox-gl-native/issues/11607",
   "query-tests/geometry/multilinestring": "needs investigation",
   "query-tests/geometry/multipolygon": "needs investigation",
   "query-tests/geometry/polygon": "needs investigation",

src/mbgl/style/expression/parsing_context.cpp

@@ -32,23 +32,36 @@ namespace style {
 namespace expression {
 
 bool isConstant(const Expression& expression) {
-    if (dynamic_cast<const Var*>(&expression)) {
-        return false;
+    if (auto varExpression = dynamic_cast<const Var*>(&expression)) {
+        return isConstant(*varExpression->getBoundExpression());
     }
-    
+
     if (auto compound = dynamic_cast<const CompoundExpressionBase*>(&expression)) {
         if (compound->getName() == "error") {
             return false;
         }
     }
+
+    bool isTypeAnnotation = dynamic_cast<const Coercion*>(&expression) ||
+        dynamic_cast<const Assertion*>(&expression) ||
+        dynamic_cast<const ArrayAssertion*>(&expression);
 
-    bool literalArgs = true;
+    bool childrenConstant = true;
     expression.eachChild([&](const Expression& child) {
-        if (!dynamic_cast<const Literal*>(&child)) {
-            literalArgs = false;
+        // We can _almost_ assume that if `expressions` children are constant,
+        // they would already have been evaluated to Literal values when they
+        // were parsed.  Type annotations are the exception, because they might
+        // have been inferred and added after a child was parsed.
+
+        // So we recurse into isConstant() for the children of type annotations,
+        // but otherwise simply check whether they are Literals.
+        if (isTypeAnnotation) {
+            childrenConstant = childrenConstant && isConstant(child);
+        } else {
+            childrenConstant = childrenConstant && dynamic_cast<const Literal*>(&child);
         }
     });
-    if (!literalArgs) {
+    if (!childrenConstant) {
         return false;
     }
 
@@ -141,13 +154,13 @@ ParseResult ParsingContext::parse(const Convertible& value, TypeAnnotationOption
         return parsed;
     }
 
-    if (expected) {
-        auto array = [&](std::unique_ptr<Expression> expression) {
-            std::vector<std::unique_ptr<Expression>> args;
-            args.push_back(std::move(expression));
-            return args;
-        };
+    auto array = [&](std::unique_ptr<Expression> expression) {
+        std::vector<std::unique_ptr<Expression>> args;
+        args.push_back(std::move(expression));
+        return args;
+    };
 
+    if (expected) {
         const type::Type actual = (*parsed)->getType();
         if ((*expected == type::String || *expected == type::Number || *expected == type::Boolean || *expected == type::Object) && actual == type::Value) {
             if (typeAnnotationOption == includeTypeAnnotations) {
@@ -169,7 +182,7 @@ ParseResult ParsingContext::parse(const Convertible& value, TypeAnnotationOption
         }
     }
 
-    // If an expression's arguments are all literals, we can evaluate
+    // If an expression's arguments are all constant, we can evaluate
     // it immediately and replace it with a literal value in the
     // parsed result.
     if (!dynamic_cast<Literal *>(parsed->get()) && isConstant(**parsed)) {