NPE in internal.idn.IdnaMappingTable.findRangesOffset

[ber4444]

       Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'char java.lang.String.charAt(int)' on a null object reference
       at okhttp3.internal.idn.IdnaMappingTable.findRangesOffset(IdnaMappingTable.java:242)
       at okhttp3.internal.idn.IdnaMappingTable.map(IdnaMappingTable.java:130)
       at okhttp3.internal._HostnamesCommonKt.idnToAscii(-HostnamesCommon.kt:322)
       at okhttp3.internal._HostnamesCommonKt.toCanonicalHost(-HostnamesCommon.kt:307)
       at okhttp3.HttpUrl$Builder.parse$okhttp(HttpUrl.java:1448)
       at okhttp3.HttpUrl$Companion.get(HttpUrl.java:1744)
       at okhttp3.HttpUrl$Companion.parse(HttpUrl.java:1754)
       at okhttp3.HttpUrl.parse(HttpUrl.java:34)
       at zipkin2.reporter.okhttp3.InternalOkHttpSender.newEndpoint(InternalOkHttpSender.java:61)
       at zipkin2.reporter.okhttp3.InternalOkHttpSender.newEndpoint(InternalOkHttpSender.java:36)

seeing the above in some Samsung devices in Crashlytics

we are using '5.0.0-alpha.14'... by the way, would love to see a new alpha, it's been 7 months already

[ber4444]

okhttp/okhttp/src/main/kotlin/okhttp3/internal/idn/IdnaMappingTable.kt

Line 242 in 02d69bf

val b0 = ranges[entryIndex].code

tries to read an index from a String that obviously doesn't exist, easy fix would be to add a sanity test before getting the index

since ranges is String shouldn't this be ranges.codePointAt(entryIndex)?

[yschimke]

I don't think that's the right fix. It's hiding a bug in the logic, the VM/compiler, or the build corrupting the file. We can make this code tolerant of corruption, but it's hiding the root problem.

For that to be out of range, it must be one of

1. Getting a bad position or limit from sections
2. Some corruption of the data, either on disk or afterwards
3. a logic (okhttp), compilation (agp) or runtime (oem) bug

Regarding why it's reading a char instead of a codepoint, the encoding is explained at the top of the file. But by this point we are really only looking the compare the last 7 bits of the target.

[yschimke]

I misread the error. It's even stranger than this.

ranges is created here

internal val IDNA_MAPPING_TABLE: IdnaMappingTable = IdnaMappingTable(
      sections =
          "\u0000\u0000
      ranges =
          "\u0000x--AP
      mappings =
          "\u0020̈\u0020
    )

So there isn't something we can fix. This is set and immutable from creation, before any methods are called.

[yschimke]

Can you provide more details about the Samsung devices seeing this error? Are they a particular version? A lot of distinct users? Are they jailbroken?

[swankjesse]

I wonder if packing data into a string is upsetting the runtime somehow.