# HG changeset patch
# User Maxim Dounin <mdounin@mdounin.ru>
# Date 1679615601 -10800
# Node ID a5e6e85106344fb19fb79da456f4e03c2f2f1236
# Parent  8771d35d55d0a2b1cefaab04401d6f837f5a05a2
Mail: fixed handling of blocked client read events in proxy.

When establishing a connection to the backend, nginx blocks reading
from the client with ngx_mail_proxy_block_read().  Previously, such
events were lost, and in some cases this resulted in connection hangs.

Notably, this affected mail_imap_ssl.t on Windows, since the test
closes connections after requesting authentication, but without
waiting for any responses (so the connection close events might be
lost).

Fix is to post an event to read from the client after connecting to
the backend if there were blocked events.

diff --git a/src/mail/ngx_mail_proxy_module.c b/src/mail/ngx_mail_proxy_module.c
--- a/src/mail/ngx_mail_proxy_module.c
+++ b/src/mail/ngx_mail_proxy_module.c
@@ -327,7 +327,9 @@ ngx_mail_proxy_pop3_handler(ngx_event_t 
         c->log->action = NULL;
         ngx_log_error(NGX_LOG_INFO, c->log, 0, "client logged in");
 
-        if (s->buffer->pos < s->buffer->last) {
+        if (s->buffer->pos < s->buffer->last
+            || s->connection->read->ready)
+        {
             ngx_post_event(c->write, &ngx_posted_events);
         }
 
@@ -486,7 +488,9 @@ ngx_mail_proxy_imap_handler(ngx_event_t 
         c->log->action = NULL;
         ngx_log_error(NGX_LOG_INFO, c->log, 0, "client logged in");
 
-        if (s->buffer->pos < s->buffer->last) {
+        if (s->buffer->pos < s->buffer->last
+            || s->connection->read->ready)
+        {
             ngx_post_event(c->write, &ngx_posted_events);
         }
 
@@ -821,7 +825,9 @@ ngx_mail_proxy_smtp_handler(ngx_event_t 
         c->log->action = NULL;
         ngx_log_error(NGX_LOG_INFO, c->log, 0, "client logged in");
 
-        if (s->buffer->pos < s->buffer->last) {
+        if (s->buffer->pos < s->buffer->last
+            || s->connection->read->ready)
+        {
             ngx_post_event(c->write, &ngx_posted_events);
         }