dir.c: chdir conflict should raise only when called in different thread

... and keep it as a warning (like 2.7) when it is called in the same
thread. [Bug #15661]

1 files changed, 3 insertions, 1 deletions

diff --git a/dir.c b/dir.c
index 49e6818d25..bedbdd9f83 100644
--- a/dir.c
+++ b/dir.c
@@ -1064,8 +1064,10 @@ dir_s_chdir(int argc, VALUE *argv, VALUE obj)
     }
 
     if (chdir_blocking > 0) {
-	if (!rb_block_given_p() || rb_thread_current() != chdir_thread)
+	if (rb_thread_current() != chdir_thread)
             rb_raise(rb_eRuntimeError, "conflicting chdir during another chdir block");
+        if (!rb_block_given_p())
+            rb_warn("conflicting chdir during another chdir block");
     }
 
     if (rb_block_given_p()) {