curlMinimal: apply paused HTTP/2 transfer fix

This is done before the final release due to how critical this bug is on
any application that relies on paused HTTP/2 transfers (e.g. Lix at high
concurrency during substitutions).

This can be removed as soon as 8.17.0 is landed.

Change-Id: I5bf8d7423447fff8e9a16e2c1ce67e432f769885
Signed-off-by: Raito Bezarius <masterancpp@gmail.com>

pkgs/by-name/cu/curlMinimal/fix-h2-paused-transfers.patch

@@ -0,0 +1,27 @@
+From 7e91f24c73256af59ac9061c41b73a184c4690aa Mon Sep 17 00:00:00 2001
+From: Stefan Eissing <stefan@eissing.org>
+Date: Mon, 3 Nov 2025 15:07:57 +0100
+Subject: [PATCH] cw-out: fix EAGAIN handling on pause
+
+The interim CURLE_AGAIN result was not always converted to a
+CURLE_OK and then caused write callers to report a failure.
+
+Fixes #19334
+Reported-by: pennae on github
+Closes #19338
+---
+ lib/cw-out.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/lib/cw-out.c b/lib/cw-out.c
+index 1f4031649267..9c0a36e7e5e2 100644
+--- a/lib/cw-out.c
++++ b/lib/cw-out.c
+@@ -302,6 +302,7 @@ static CURLcode cw_out_buf_flush(struct cw_out_ctx *ctx,
+                               &consumed);
+     if(result && (result != CURLE_AGAIN))
+       return result;
++    result = CURLE_OK;
+ 
+     if(consumed) {
+       if(consumed == curlx_dyn_len(&cwbuf->b)) {

pkgs/by-name/cu/curlMinimal/package.nix

@@ -98,6 +98,14 @@ stdenv.mkDerivation (finalAttrs: {
     hash = "sha256-QMjN28tsxiUcA96kI6Ryps6kA3vmVLpc9d7G6y0i/x0=";
   };
 
+  patches = [
+    # Bug introduced in curl@fa915b (8.16.0) https://github.com/curl/curl/issues/19334 Paused
+    # HTTP/2 transfers will return the wrong errors and trash the whole
+    # transfer. Remove this patch once curl is updated to 8.17.0 which will be
+    # released on the 5th November 2025.
+    ./fix-h2-paused-transfers.patch
+  ];
+
   # this could be accomplished by updateAutotoolsGnuConfigScriptsHook, but that causes infinite recursion
   # necessary for FreeBSD code path in configure
   postPatch = ''