15.4.2 (January 6, 2017)

React

• Fixed build issues with the Brunch bundler. (@gaearon in #8686)
• Improved error messages for invalid element types. (@sophiebits in #8612)
• Removed a warning about getInitialState when this.state is set. (@bvaughn in #8594)
• Removed some dead code. (@diegomura in #8050, @dfrownfelter in #8597)

React DOM

• Fixed a decimal point issue on uncontrolled number inputs. (@nhunzaker in #7750)
• Fixed rendering of textarea placeholder in IE11. (@aweary in #8020)
• Worked around a script engine bug in IE9. (@eoin in #8018)

React Addons

• Fixed build issues in RequireJS and SystemJS environments. (@gaearon in #8686)
• Added missing package dependencies. (@kweiberth in #8467)

15.4.1 (November 22, 2016)

React

• Restructure variable assignment to work around a Rollup bug (@gaearon in #8384)

React DOM

• Fixed event handling on disabled button elements (@sophiebits in #8387)
• Fixed compatibility of browser build with AMD environments (@zpao in #8374)

15.4.0 (November 16, 2016)

React

• React package and browser build no longer "secretly" includes React DOM. (@sebmarkbage in #7164 and #7168)
• Required PropTypes now fail with specific messages for null and undefined. (@chenglou in #7291)
• Improved development performance by freezing children instead of copying. (@keyanzhang in #7455)

React DOM

• Fixed occasional test failures when React DOM is used together with shallow renderer. (@goatslacker in #8097)
• Added a warning for invalid aria- attributes. (@jessebeach in #7744)
• Added a warning for using autofocus rather than autoFocus. (@hkal in #7694)
• Removed an unnecessary warning about polyfilling String.prototype.split. (@nhunzaker in #7629)
• Clarified the warning about not calling PropTypes manually. (@jedwards1211 in #7777)
• The unstable batchedUpdates API now passes the wrapped function's return value through. (@bgnorlov in #7444)
• Fixed a bug with updating text in IE 8. (@mnpenner in #7832)

React Perf

• When ReactPerf is started, you can now view the relative time spent in components as a chart in Chrome Timeline. (@gaearon in #7549)

React Test Utils

• If you call Simulate.click() on a <input disabled onClick={foo} /> then foo will get called whereas it didn't before. (@nhunzaker in #7642)

React Test Renderer

• Due to packaging changes, it no longer crashes when imported together with React DOM in the same file. (@sebmarkbage in #7164 and #7168)
• ReactTestRenderer.create() now accepts {createNodeMock: element => mock} as an optional argument so you can mock refs with snapshot testing. (@Aweary in #7649, #8261)