After upgrading kotlin 2.3.21 -> 2.4.10, compose branch coverage drop down

[neworld]

Steps to reproduce

• JaCoCo version: 0.8.15 (also 0.8.14, older version has very different branch coverage result)
• Operating system: Linux
• Tool integration: Gradle + Kotlin + Kover
• Complete executable reproducer: Improve sample to demonstrate branch increase after kotlin upgrade example-jacoco-kotlin-compose#140
• Steps:

1. Checkout repo
2. Run ./gradlew test jacocoTestReport
3. Open build/reports/jacoco/test/html/org.example/index.source.html

4. Change kotlin version to 2.3.21 5. Run `./gradlew test jacocoTestReport` and refresh browser

Expected behaviour

Give same amount of branch coverage

Actual behaviour

Increases number of branches, but coverage decreases

Extra info

Kotlin upgrade in our product cause significant coverage drop, which is enough to prevent upgrade to kotlin. Sometimes it was +120 branches per composable. I tried to make small as possible repro.

I wasn't sure at first whether this is the right place to report it, but similar problems were fixed here in #1616 and #1911. Let me know if it belongs elsewhere.

I have no idea if it even makes sense, but AI explained it like this:

AI Analysis

The difference is in the lambda memoization check inside the CC(remember) region (between sourceInformationMarkerStart/End). javap -c of ExampleKt.example, the check for the captured state parameter:

Kotlin 2.3.21 — an unconditional changedInstance() call, no extra branches, which roughly corresponds to:

val invalidated = $composer.changedInstance(state) or
        ($changed and 0b1110000 == 0b0100000)  // onDone

Kotlin 2.4.10 — the same capture now consults the caller-provided $changed bits before falling back to changedInstance(), adding three conditionals, which roughly corresponds to:

val invalidated = ($changed and 0b0001110 == 0b0000100 ||
        ($changed and 0b0001000 != 0 && $composer.changedInstance(state))) or
        ($changed and 0b1110000 == 0b0100000)  // onDone

The result is used as if (invalidated || rememberedValue === Empty) { create and cache the lambda } else { reuse cached }. Some of these branch outcomes depend on bits computed by the caller, so they cannot be reliably exercised by tests. It would be great if KotlinComposeFilter also filtered this pattern.