Don't crash reading non-ASCII characters from the server or the cache.

[swankjesse]

This doesn't completely support ISO-8859-1 headers; instead they will most likely
be mangled when they are decoded as UTF-8. If we decide we absolutely must support
ISO-8859-1 here we can do that in another change. (I'm not currently enthusiastic
about this idea.)

But this does prevent OkHttp from crashing when it encounters non-ASCII characters
in headers for HTTP/2, SPDY, and cached responses.

Closes: #1998

[BlaineRideCell]

I am still seeing this issue with OkHttp, version 3.6, and Retrofit 2.2.0. Here is my stacktrace:

03-13 12:08:17.730 18865-19003/com.my.app.dev E/AndroidRuntime: FATAL EXCEPTION: OkHttp Dispatcher Process:com.my.app.dev, PID: 18865 java.lang.IllegalArgumentException: Unexpected char 0x10c at 0 in x-locale value: Česká republika at okhttp3.Headers$Builder.checkNameAndValue(Headers.java:320) at okhttp3.Headers$Builder.set(Headers.java:300) at okhttp3.Request$Builder.header(Request.java:164) at com.ridecell.rest.RetrofitClient$1.intercept(RetrofitClient.java:125) at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:92) at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:67) at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:179) at okhttp3.RealCall$AsyncCall.execute(RealCall.java:129) at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607) at java.lang.Thread.run(Thread.java:761)

[manjunath143]

@swankjesse
I just tried passing ISO-8859-1 non-ASCII string as header.
String header="";
try {
String s="ääääääääääääääääääää";
header=new String(s.getBytes("UTF-8"), "ISO-8859-1")
}catch (UnsupportedEncodingException e){
e.getStackTrace();
}

But it did not work. Just curious to know if okhttp supports this ?