closes #2454

lib/browser/common/util/check.js

@@ -60,7 +60,16 @@ export function isString(value) {
  * @returns { Boolean } -
  */
 export function isBlank(value) {
-  return isUndefined(value) || value === null || value === ''
+  return isNil(value) || value === ''
+}
+
+/**
+ * Check against the null and undefined values
+ * @param   { * }  value -
+ * @returns {Boolean} -
+ */
+export function isNil(value) {
+  return isUndefined(value) || value === null
 }
 
 /**

lib/browser/tag/update.js

@@ -158,7 +158,8 @@ export function updateExpression(expr) {
 
   // remove original attribute
   if (expr.attr && (!expr.isAttrRemoved || !hasValue || value === false)) {
-    remAttr(dom, expr.attr)
+    // remove either riot-* attributes or just the attribute name
+    remAttr(dom, getAttr(dom, expr.attr) ? expr.attr : attrName)
     expr.isAttrRemoved = true
   }
 
@@ -175,7 +176,7 @@ export function updateExpression(expr) {
   // if the value is an object we can not do much more with it
   if (isObj && !isToggle) return
   // avoid to render undefined/null values
-  if (isBlank(value)) value = ''
+  if (!hasValue) value = ''
 
   // textarea and text nodes have no attribute name
   if (!attrName) {

test/specs/browser/riot/core.spec.js

@@ -1513,4 +1513,20 @@ describe('Riot core', function() {
     expect(tag.refs.foo).to.be.undefined
     tag.unmount()
   })
+
+  it('remove style attributes if they contain blank values', function() {
+    injectHTML('<riot-tmp></riot-tmp>')
+
+    riot.tag('riot-tmp', "<p ref='p' riot-style=\"{changed ? 'background-color: green' : ''}\"></p>", function() {
+      this.changed = true
+    })
+
+    var tag = riot.mount('riot-tmp')[0]
+    expect(tag.refs.p.hasAttribute('style')).to.be.ok
+    tag.changed = false
+    tag.update()
+    expect(tag.refs.p.hasAttribute('style')).to.be.not.ok
+
+    tag.unmount()
+  })
 })