merge revision(s) 611e711085c7e3984555a79626d025c8b876eced,a9c5c2d614f30a616970245fef3e7ffc151e2ecf: [Backport #17527]

Test incorrect behaviour of `rb_io_wait_readable/writable`.

	---
	 test/fiber/test_io.rb | 35 +++++++++++++++++++++++++++++++++++
	 1 file changed, 35 insertions(+)

	Check errno before invoking scheduler in
	 `rb_io_wait_readable/writable`.

	See <https://bugs.ruby-lang.org/issues/17527> for more details.
	---
	 io.c | 66 +++++++++++++++++++++++++++++++++++-------------------------------
	 1 file changed, 35 insertions(+), 31 deletions(-)

io.c

@@ -1306,14 +1306,11 @@ rb_io_from_fd(int fd)
 int
 rb_io_wait_readable(int f)
 {
-    VALUE scheduler = rb_scheduler_current();
+    VALUE scheduler;
-    if (scheduler != Qnil) {
-        return RTEST(
-            rb_scheduler_io_wait_readable(scheduler, rb_io_from_fd(f))
-        );
-    }
 
     io_fd_check_closed(f);
+
+    scheduler = rb_scheduler_current();
     switch (errno) {
       case EINTR:
 #if defined(ERESTART)
@@ -1326,7 +1323,13 @@ rb_io_wait_readable(int f)
 #if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
       case EWOULDBLOCK:
 #endif
+        if (scheduler != Qnil) {
+            return RTEST(
+                rb_scheduler_io_wait_readable(scheduler, rb_io_from_fd(f))
+            );
+        } else {
             rb_thread_wait_fd(f);
+        }
         return TRUE;
 
       default:
@@ -1337,14 +1340,11 @@ rb_io_wait_readable(int f)
 int
 rb_io_wait_writable(int f)
 {
-    VALUE scheduler = rb_scheduler_current();
+    VALUE scheduler;
-    if (scheduler != Qnil) {
-        return RTEST(
-            rb_scheduler_io_wait_writable(scheduler, rb_io_from_fd(f))
-        );
-    }
 
     io_fd_check_closed(f);
+
+    scheduler = rb_scheduler_current();
     switch (errno) {
       case EINTR:
 #if defined(ERESTART)
@@ -1366,7 +1366,13 @@ rb_io_wait_writable(int f)
 #if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
       case EWOULDBLOCK:
 #endif
+        if (scheduler != Qnil) {
+            return RTEST(
+                rb_scheduler_io_wait_writable(scheduler, rb_io_from_fd(f))
+            );
+        } else {
             rb_thread_fd_writable(f);
+        }
         return TRUE;
 
       default:

test/fiber/test_io.rb

@@ -62,4 +62,39 @@ class TestFiberIO < Test::Unit::TestCase
       end
     end.each(&:join)
   end
+
+  def test_epipe_on_read
+    skip "UNIXSocket is not defined!" unless defined?(UNIXSocket)
+
+    i, o = UNIXSocket.pair
+
+    unless i.nonblock? && o.nonblock?
+      i.close
+      o.close
+      skip "I/O is not non-blocking!"
+    end
+
+    error = nil
+
+    thread = Thread.new do
+      scheduler = Scheduler.new
+      Fiber.set_scheduler scheduler
+
+      Fiber.schedule do
+        begin
+          i.close
+          o.write(MESSAGE)
+        rescue => error
+          # Saved into error.
+        end
+      end
+    end
+
+    thread.join
+
+    i.close
+    o.close
+
+    assert_kind_of Errno::EPIPE, error
+  end
 end

version.h

@@ -12,11 +12,11 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 2
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 71
+#define RUBY_PATCHLEVEL 72
 
 #define RUBY_RELEASE_YEAR 2021
 #define RUBY_RELEASE_MONTH 4
-#define RUBY_RELEASE_DAY 18
+#define RUBY_RELEASE_DAY 24
 
 #include "ruby/version.h"