Add toString on error object to prevent a segfault

src/ms_error.cpp

@@ -6,6 +6,8 @@ void MSError::Initialize(v8::Local<v8::Object> target) {
   v8::Local<v8::FunctionTemplate> tpl = Nan::New <v8::FunctionTemplate>(MSError::New);
   tpl->InstanceTemplate()->SetInternalFieldCount(1);
   tpl->SetClassName(Nan::New("MSError").ToLocalChecked());
+  Nan::SetPrototypeMethod(tpl, "toString", ToString);
+  Nan::SetPrototypeMethod(tpl, "toDetailString", ToString);
 
   Nan::SetNamedPropertyHandler(
         tpl->InstanceTemplate()
@@ -52,6 +54,11 @@ v8::Local<v8::Value> MSError::NewInstance(errorObj *err_ptr) {
   return scope.Escape(Nan::New(constructor)->GetFunction()->NewInstance(1, &ext));
 }
 
+NAN_METHOD(MSError::ToString) {
+  MSError *err = Nan::ObjectWrap::Unwrap<MSError>(info.Holder());
+  info.GetReturnValue().Set(Nan::New(err->this_->message).ToLocalChecked());
+}
+
 NAN_PROPERTY_GETTER(MSError::NamedPropertyGetter) {
   MSError *err = Nan::ObjectWrap::Unwrap<MSError>(info.Holder());
 

src/ms_error.hpp

@@ -13,9 +13,12 @@ class MSError: public Nan::ObjectWrap {
     static NAN_METHOD(New);
     static v8::Local<v8::Value> NewInstance(errorObj* err_ptr);
 
+    static NAN_METHOD(ToString);
+
     MSError();
     MSError(errorObj *err);
     inline errorObj *get() { return this_; }
+    errorObj *this_;
 
   protected:
     static NAN_PROPERTY_GETTER(NamedPropertyGetter);
@@ -24,7 +27,6 @@ class MSError: public Nan::ObjectWrap {
 
   private:
     ~MSError();
-    errorObj *this_;
 };
 
 #endif

tests/data/bad.map

@@ -0,0 +1,21 @@
+MAP
+NAME GMAP_DEMO
+STATUS ON
+SIZE 600 300
+EXTENT -180 -90 180 90
+UNITS DD
+SHAPEPATH "./foo/bar"
+IMAGECOLOR 255 255 255
+PROJECTION
+  "init=epsg:4326"
+END
+LAYER
+  PROJECTION
+    "init=epsg:4326"
+  END
+  NAME prov_bound
+  TYPE POLYGON
+  STATUS ON
+  DATA "foo/wgs_province"
+END
+END

tests/tests.js

@@ -28,6 +28,7 @@ var fs = require('fs');
 var path = require('path');
 var datadir = path.join(__dirname, 'data');
 var mapfile = path.join(datadir, 'test.map');
+var badmapfile = path.join(datadir, 'bad.map');
 var symbolfile = path.join(datadir, 'symbolset.txt');
 var nomapfile = 'missing.map';
 var map;
@@ -533,6 +534,8 @@ describe('mapserver', function() {
 
       var defaultLayerText = 'LAYER\n  NAME "foo"\n  STATUS OFF\n  TILEITEM "location"\n  UNITS METERS\nEND # LAYER\n\n';
 
+console.log(layer)
+
       assert.equal(layer.toString(), defaultLayerText, 'unexpected default layer text ' + layer.toString());
     });
 
@@ -571,6 +574,26 @@ describe('mapserver', function() {
     });
   });
 
+  it('should not segfault', function(done) {
+    var v = mapserver.getVersionInt();
+    assert.doesNotThrow(function() {
+      map = new mapserver.Map(badmapfile);
+    }, Error, 'loading a invalid map file should throw an error.');
+
+    map.drawMap(function(drawError, buffer) {
+      if (drawError) {
+        console.log('error', drawError)
+        assert.ok(true, 'Returned error from bad map')
+        done();
+      } else {
+        fs.writeFileSync(path.join(__dirname, 'data', 'bad_out_'+v+'.png'), buffer);
+
+        assert.ok(false, 'Did not receive error drawing map.');
+      }
+    });
+  });
+
+
   it('should get the label cache', function(done) {
     assert.doesNotThrow(function() {
       map = new mapserver.Map(mapfile);