Disk cached image with non-ASCII headers can't be updated after 304 Not Modified

[fingertricks]

Describe the bug
When a disk cached image includes header values that are non-ASCII, updating the disk cache after a 304 Not Modified fails with an exception which causes image loading to fail.

I also have a fix for this, which I'll submit shortly, but here's the details of the issue below.

To Reproduce
Example image: https://just-eat-prod-eu-res.cloudinary.com/image/upload/c_fill,g_center,h_400,w_500/v1/experiments/projecticing/es/cuisine-icons/alimentaci%C3%B3n.webp

Returns headers which are correctly persisted to the disk cache as follows:

1691404585044
1691404585064
1
16
content-disposition: inline; filename="alimentación.webp"
content-type: image/webp
etag: "232087ad43c9820865f16ce05438fa59"
last-modified: Wed, 23 Nov 2022 14:43:23 GMT
x-request-id: f844e7f14d102b27ede9c531c65c51ba
date: Mon, 07 Aug 2023 10:36:27 GMT
strict-transport-security: max-age=604800
cache-control: public, no-transform, max-age=86400
server-timing: cld-fastly;mitm=p;dur=1;cpu=0;start=2023-08-07T10:36:27.159Z;desc=hit,rtt;dur=0
server: Cloudinary
timing-allow-origin: *
access-control-allow-origin: *
accept-ranges: bytes
x-content-type-options: nosniff
access-control-expose-headers: Content-Length,Content-Disposition,ETag,Server-Timing,X-Content-Type-Options
content-length: 17388

When the max-age expires 1 day later (or the disk cached max-age is modified to say 60s), a new server request is sent which returns a 304. However Coil fails as follows:

2023-08-07 16:59:00.454 22744-23063 okhttp.OkHttpClient     com.***             I  --> GET https://just-eat-prod-eu-res.cloudinary.com/image/upload/c_fill,g_center,h_400,w_500/v1/experiments/projecticing/es/cuisine-icons/alimentaci%C3%B3n.webp
2023-08-07 16:59:00.706 22744-23063 okhttp.OkHttpClient     com.***            I  <-- 304 https://just-eat-prod-eu-res.cloudinary.com/image/upload/c_fill,g_center,h_400,w_500/v1/experiments/projecticing/es/cuisine-icons/alimentaci%C3%B3n.webp (251ms)
2023-08-07 16:59:00.736 22744-22744 RealImageLoader         com.***             I  🚨 Failed - https://just-eat-prod-eu-res.cloudinary.com/image/upload/c_fill,g_center,h_400,w_500/v1/experiments/projecticing/es/cuisine-icons/alimentaci%C3%B3n.webp - java.lang.IllegalArgumentException: Unexpected char 0x301 at 29 in content-disposition value: inline; filename="alimentación.webp"

Logs/Screenshots
Stack as follows points to issue within CacheStrategy.combineHeaders():

cause = {IllegalArgumentException@44000} "java.lang.IllegalArgumentException: Unexpected char 0x301 at 29 in content-disposition value: inline; filename="alimentación.webp""
detailMessage = "Unexpected char 0x301 at 29 in content-disposition value: inline; filename="alimentación.webp""
stackTrace = {StackTraceElement[15]@44021} 
 0 = {StackTraceElement@44024} "okhttp3.Headers$Companion.checkValue(Headers.kt:450)"
 1 = {StackTraceElement@44025} "okhttp3.Headers$Companion.access$checkValue(Headers.kt:362)"
 2 = {StackTraceElement@44026} "okhttp3.Headers$Builder.add(Headers.kt:261)"
 3 = {StackTraceElement@44027} "coil.network.CacheStrategy$Companion.combineHeaders(CacheStrategy.kt:245)"
 4 = {StackTraceElement@44028} "coil.fetch.HttpUriFetcher.writeToDiskCache(HttpUriFetcher.kt:159)"
 5 = {StackTraceElement@44029} "coil.fetch.HttpUriFetcher.fetch(HttpUriFetcher.kt:80)"
 6 = {StackTraceElement@44030} "coil.fetch.HttpUriFetcher$fetch$1.invokeSuspend(Unknown Source:14)"
 7 = {StackTraceElement@44031} "kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)"
 8 = {StackTraceElement@44032} "kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)"
 9 = {StackTraceElement@44033} "kotlinx.coroutines.internal.LimitedDispatcher.run(LimitedDispatcher.kt:42)"

Version
2.3.0, but have also reproduced on latest main.