don't throw an exception in the map thread for bad styles

src/mbgl/style/style.cpp

@@ -5,7 +5,6 @@
 #include <mbgl/style/style_parser.hpp>
 #include <mbgl/style/style_bucket.hpp>
 #include <mbgl/util/constants.hpp>
-#include <mbgl/util/error.hpp>
 #include <mbgl/util/std.hpp>
 #include <mbgl/util/uv_detail.hpp>
 #include <mbgl/platform/log.hpp>
@@ -75,7 +74,7 @@ void Style::loadJSON(const uint8_t *const data) {
     doc.Parse<0>((const char *const)data);
     if (doc.HasParseError()) {
         Log::Error(Event::ParseStyle, "Error parsing style JSON at %i: %s", doc.GetErrorOffset(), doc.GetParseError());
-        throw error::style_parse(doc.GetErrorOffset(), doc.GetParseError());
+        return;
     }
 
     StyleParser parser;

src/mbgl/util/error.hpp

@@ -1,20 +0,0 @@
-#ifndef MBGL_UTIL_ERROR
-#define MBGL_UTIL_ERROR
-
-#include <stdexcept>
-#include <string>
-
-namespace mbgl {
-namespace error {
-
-struct style_parse : std::exception {
-    inline style_parse(size_t offset_, const char *msg_) : offset(offset_), msg(msg_) {}
-    inline const char* what() const noexcept { return msg.c_str(); }
-    const size_t offset;
-    const std::string msg;
-};
-}
-
-}
-
-#endif

test/api/set_style.cpp

@@ -0,0 +1,32 @@
+#include "../fixtures/util.hpp"
+#include "../fixtures/fixture_log_observer.hpp"
+
+#include <mbgl/map/map.hpp>
+#include <mbgl/platform/default/headless_view.hpp>
+#include <mbgl/platform/default/headless_display.hpp>
+#include <mbgl/storage/default_file_source.hpp>
+
+
+TEST(API, SetStyle) {
+    using namespace mbgl;
+
+    auto display = std::make_shared<mbgl::HeadlessDisplay>();
+    HeadlessView view(display);
+    DefaultFileSource fileSource(nullptr);
+
+    Log::setObserver(util::make_unique<FixtureLogObserver>());
+
+    Map map(view, fileSource);
+
+    map.start(Map::Mode::Static);
+
+    map.setStyleJSON("invalid", "test/suite");
+
+    map.stop();
+
+    auto observer = Log::removeObserver();
+    auto flo = dynamic_cast<FixtureLogObserver*>(observer.get());
+    EXPECT_EQ(1ul, flo->count({ EventSeverity::Error, Event::ParseStyle, -1,
+        "Error parsing style JSON at 0: Expect either an object or array at root" }));
+    EXPECT_TRUE(flo->unchecked().empty());
+}

test/test.gyp

@@ -35,6 +35,8 @@
         'fixtures/fixture_log_observer.hpp',
         'fixtures/fixture_log_observer.cpp',
 
+        'api/set_style.cpp',
+
         'headless/headless.cpp',
 
         'miscellaneous/clip_ids.cpp',