curl_easy_pause.3: mention h2/h3 buffering

Asked-by: Maxim Dzhura
Ref: https://curl.se/mail/lib-2023-10/0011.html

Closes #12045

diff --git a/docs/libcurl/curl_easy_pause.3 b/docs/libcurl/curl_easy_pause.3
index 7d53eac584e5a1a2ee95479cc0284aaf92f212f8..f3a879391e33acd5801a0dc760792f2f03e04ba0 100644 (file)
--- a/docs/libcurl/curl_easy_pause.3
+++ b/docs/libcurl/curl_easy_pause.3
@@ -106,6 +106,11 @@ effect that if you download something that is compressed a lot, it can result
 in a large data amount needing to be allocated to save the data during the
 pause. consider not using paused receiving if you allow libcurl to uncompress
 data automatically.
+
+If the download is done with HTTP/2 or HTTP/3, there is up to a stream window
+size worth of data that curl cannot stop but instead needs to cache while the
+transfer is paused. This means that if a window size of 64 MB is used, libcurl
+might end up having to cache 64 MB of data.
 .SH AVAILABILITY
 Added in 7.18.0.
 .SH RETURN VALUE