v4-0001-oauth-Report-cleanup-errors-as-warnings-on-stderr.patch

From 62c795ef489f4cbf29d543e92d99875b75291e24 Mon Sep 17 00:00:00 2001
From: Jacob Champion <jacob.champion@enterprisedb.com>
Date: Fri, 30 Jan 2026 16:41:26 -0800
Subject: [PATCH v4 1/6] oauth: Report cleanup errors as warnings on stderr

Using conn->errorMessage for these "shouldn't-happen" cases will only
work if the connection itself fails. Our SSL and password callbacks
print WARNINGs when they find themselves in similar situations, so
follow their lead.

Reviewed-by: Zsolt Parragi <zsolt.parragi@percona.com>
Discussion: https://postgr.es/m/CAOYmi%2BmEU_q9sr1PMmE-4rLwFN%3DOjyndDwFZvpsMU3RNJLrM9g%40mail.gmail.com
---
 src/interfaces/libpq-oauth/oauth-curl.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/src/interfaces/libpq-oauth/oauth-curl.c b/src/interfaces/libpq-oauth/oauth-curl.c
index 691e7ec1d9f..2c147f98d0d 100644
--- a/src/interfaces/libpq-oauth/oauth-curl.c
+++ b/src/interfaces/libpq-oauth/oauth-curl.c
@@ -286,17 +286,15 @@ struct async_ctx
  * Tears down the Curl handles and frees the async_ctx.
  */
 static void
-free_async_ctx(PGconn *conn, struct async_ctx *actx)
+free_async_ctx(struct async_ctx *actx)
 {
 	/*
 	 * In general, none of the error cases below should ever happen if we have
 	 * no bugs above. But if we do hit them, surfacing those errors somehow
 	 * might be the only way to have a chance to debug them.
 	 *
-	 * TODO: At some point it'd be nice to have a standard way to warn about
-	 * teardown failures. Appending to the connection's error message only
-	 * helps if the bug caused a connection failure; otherwise it'll be
-	 * buried...
+	 * Print them as warnings to stderr, following the example of similar
+	 * situations in fe-secure-openssl.c and fe-connect.c.
 	 */
 
 	if (actx->curlm && actx->curl)
@@ -304,9 +302,9 @@ free_async_ctx(PGconn *conn, struct async_ctx *actx)
 		CURLMcode	err = curl_multi_remove_handle(actx->curlm, actx->curl);
 
 		if (err)
-			libpq_append_conn_error(conn,
-									"libcurl easy handle removal failed: %s",
-									curl_multi_strerror(err));
+			fprintf(stderr,
+					libpq_gettext("WARNING: libcurl easy handle removal failed: %s\n"),
+					curl_multi_strerror(err));
 	}
 
 	if (actx->curl)
@@ -324,9 +322,9 @@ free_async_ctx(PGconn *conn, struct async_ctx *actx)
 		CURLMcode	err = curl_multi_cleanup(actx->curlm);
 
 		if (err)
-			libpq_append_conn_error(conn,
-									"libcurl multi handle cleanup failed: %s",
-									curl_multi_strerror(err));
+			fprintf(stderr,
+					libpq_gettext("WARNING: libcurl multi handle cleanup failed: %s\n"),
+					curl_multi_strerror(err));
 	}
 
 	free_provider(&actx->provider);
@@ -359,7 +357,7 @@ pg_fe_cleanup_oauth_flow(PGconn *conn)
 
 	if (state->async_ctx)
 	{
-		free_async_ctx(conn, state->async_ctx);
+		free_async_ctx(state->async_ctx);
 		state->async_ctx = NULL;
 	}
 
-- 
2.34.1