check muiTheme is defined

[tyfoo]

TimePicker dialog wont open when muiTheme is null/undefined. Steps to reproduce:

1. Browse to http://material-ui.com/#/components/time-picker
2. Open the console on browser
3. Click on any of the TimePicker input fields.

• Uncaught TypeError: Cannot read property 'isRtl' of undefined

Source: /src/time-picker/clock.jsx line 118 <div style={this.prepareStyles(styles.root)}>, styles.root is {}.

Fix: added a double check to ensureDirection to check muiTheme is not null or undefined before checking its isRtl property.

[oliviertassinari]

@tyfoo Thanks for this PR. However, the issue you discribed is already fixed by #1922.
@shaurya947 Should we close this one?

[tyfoo]

@oliviertassinari thanks for the quick feedback.

I am not sure #1922 solves this issue, as clock.jsx does not use muiTheme from the context.

I believe the issue is cause by line 96 in clock.jsx:

let styles = {
      root: {},

      container: {
        height: 280,
        padding: 10,
      },
    };

which it then passes to prepareStyles in line 118:

<div style={this.prepareStyles(styles.root)}>

I believe that gets passed down as undefined or null which throws and exception in ensureDirection.

[shaurya947]

@oliviertassinari I'm thinking if we can solve the problem at its root (prepareStyles)

[shaurya947]

See my last comment on #1674 guys

[tyfoo]

@oliviertassinari @shaurya947 Thanks for the feedback. Should I close this PR?

[oliviertassinari]

@tyfoo Yes, I think that we can close this PR since the orignal issue is solved.