Safari can't open the page. The error was: "cannot parse response".

[sourcesimian]

On iOS 18.1 Safari returns Safari can't open the page. The error was: "cannot parse response". for chunked responses.

This appears to be caused by

ESPAsyncWebServer/src/WebResponses.cpp

Lines 320 to 321 in 7f37534

	outLen = sprintf((char*)buf+headLen, "%x", readLen) + headLen;
	while(outLen < headLen + 4) buf[outLen++] = ' ';

which can introduce trailing whitespace padding for chunk sizes less than 0x1000, which RFC 2616 (Section 3.6.1) seems to say that no extra whitespace is allowed after the chunk size other than the CRLF.

Reproducer (open: http://127.0.0.1:8088)
demo-bad.http.txt

while true; do nc -l 8088 < ./demo-bad.http.txt; done

Working:
demo-good.http.txt

while true; do nc -l 8088 < ./demo-good.http.txt; done