JSON decodeFromString never terminates with some invalid inputs (JsonLexer.skipElement loops infinitely) => huge battery drain.

[valeriyo]

Duplicating from https://youtrack.jetbrains.com/issue/KT-46611

Using Kotlin 1.5.0 with org.jetbrains.kotlinx:kotlinx-serialization-json:1.2.0 (latest)

Given:

@Serializable
class Something

val json = Json { ignoreUnknownKeys = true }

.. this expression never terminates (with an exception) as it should, because the input is not valid JSON:

json.decodeFromString(Something.serializer(), """{"a":[{"b":[{"c":{}d",""e"":"}]}""")

Looks like the JsonLexer hits the end of input string, thus consumeNextToken() returns TC_EOF. After that, the while loop inside skipElement() keeps spinning forever.

[sandwwraith]

Have it worked with 1.1.0? Seems that is a general bug, not a regression....

[valeriyo]

I wouldn't know, but since 1.2.0 generates garbage (#1455) -- I hit this issue.