main/poll: Fix kqueue event buffer overflow in grouped mode

ext/standard/tests/poll/poll_stream_sock_rw_max_events.phpt

@@ -0,0 +1,38 @@
+--TEST--
+Poll stream - socket read/write events with maxEvents equal to the FD count
+--FILE--
+<?php
+require_once __DIR__ . '/poll.inc';
+
+$poll_ctx = pt_new_stream_poll();
+
+// Each FD is ready for both read and write. Backends that report read and
+// write separately (kqueue) see twice as many events as FDs and have to merge
+// them without dropping any FD, filling only half of the maxEvents entries.
+$writers = [];
+$expected = [];
+for ($i = 0; $i < 4; $i++) {
+    list($reader, $writer) = pt_new_socket_pair();
+    $writers[$i] = $writer;
+    pt_stream_poll_add($poll_ctx, $reader, [Io\Poll\Event::Read, Io\Poll\Event::Write], "sock$i");
+    pt_write_sleep($writer, "test $i data");
+    $expected[] = [
+        'events' => [Io\Poll\Event::Read, Io\Poll\Event::Write],
+        'data' => "sock$i",
+        'read' => "test $i data",
+    ];
+}
+
+pt_expect_events($poll_ctx->wait(0, 100000, 8), $expected);
+
+// All read data was drained above, so only write events remain
+$expected = [];
+for ($i = 0; $i < 4; $i++) {
+    $expected[] = ['events' => [Io\Poll\Event::Write], 'data' => "sock$i"];
+}
+pt_expect_events($poll_ctx->wait(0, 100000, 8), $expected);
+
+?>
+--EXPECT--
+Events matched - count: 4
+Events matched - count: 4

ext/standard/tests/poll/poll_stream_tcp_read_max_events.phpt

@@ -0,0 +1,45 @@
+--TEST--
+Poll stream - TCP read with maxEvents smaller than the number of ready FDs
+--FILE--
+<?php
+require_once __DIR__ . '/poll.inc';
+
+list($clients, $servers) = pt_new_tcp_socket_connections(8);
+$poll_ctx = pt_new_stream_poll();
+
+for ($i = 0; $i < count($servers); $i++) {
+    pt_stream_poll_add($poll_ctx, $servers[$i], [Io\Poll\Event::Read], "server$i");
+}
+
+for ($i = 0; $i < count($clients); $i++) {
+    pt_write_sleep($clients[$i], "test $i data");
+}
+
+// 8 FDs are ready but only 4 events fit into the buffer, so the remaining
+// events must be delivered by the following wait() without any duplicates.
+$seen = [];
+for ($round = 1; $round <= 2; $round++) {
+    $watchers = $poll_ctx->wait(0, 100000, 4);
+    echo "Round $round count: " . count($watchers) . "\n";
+    foreach ($watchers as $watcher) {
+        $data = $watcher->getData();
+        if (isset($seen[$data])) {
+            echo "Duplicate event for $data\n";
+        }
+        $seen[$data] = true;
+        // Drain so level triggering does not re-report the FD
+        fread($watcher->getHandle()->getStream(), 1024);
+    }
+}
+
+ksort($seen);
+echo "Seen: " . implode(',', array_keys($seen)) . "\n";
+
+pt_expect_events($poll_ctx->wait(0), []);
+
+?>
+--EXPECT--
+Round 1 count: 4
+Round 2 count: 4
+Seen: server0,server1,server2,server3,server4,server5,server6,server7
+Events matched - count: 0

ext/standard/tests/poll/poll_stream_tcp_read_one_shot_max_events.phpt

@@ -0,0 +1,46 @@
+--TEST--
+Poll stream - TCP read oneshot with maxEvents smaller than the number of ready FDs
+--FILE--
+<?php
+require_once __DIR__ . '/poll.inc';
+
+list($clients, $servers) = pt_new_tcp_socket_connections(8);
+$poll_ctx = pt_new_stream_poll();
+
+for ($i = 0; $i < count($servers); $i++) {
+    pt_stream_poll_add($poll_ctx, $servers[$i], [Io\Poll\Event::Read, Io\Poll\Event::OneShot], "server$i");
+}
+
+for ($i = 0; $i < count($clients); $i++) {
+    pt_write_sleep($clients[$i], "test $i data");
+}
+
+// 8 oneshot FDs are ready but only 4 events fit into the buffer. The events
+// that did not fit must not be consumed - the following wait() has to deliver
+// them, and each oneshot event must be delivered exactly once.
+$seen = [];
+for ($round = 1; $round <= 2; $round++) {
+    $watchers = $poll_ctx->wait(0, 100000, 4);
+    echo "Round $round count: " . count($watchers) . "\n";
+    foreach ($watchers as $watcher) {
+        $data = $watcher->getData();
+        if (isset($seen[$data])) {
+            echo "Duplicate event for $data\n";
+        }
+        $seen[$data] = true;
+    }
+}
+
+ksort($seen);
+echo "Seen: " . implode(',', array_keys($seen)) . "\n";
+
+// Every oneshot watcher fired once, so new data must not be reported
+pt_write_sleep($clients[0], "more data");
+pt_expect_events($poll_ctx->wait(0, 100000), []);
+
+?>
+--EXPECT--
+Round 1 count: 4
+Round 2 count: 4
+Seen: server0,server1,server2,server3,server4,server5,server6,server7
+Events matched - count: 0