make 'checkdied' in runtests.pl more robust

diff --git a/tests/runtests.pl b/tests/runtests.pl
index f2ed1650daf8bc3b6b94a25ec1cf71f01d623af7..9e5a8674c1a18641f96f54aa9a9b0b49f06e32b2 100755 (executable)
--- a/tests/runtests.pl
+++ b/tests/runtests.pl
@@ -258,8 +258,11 @@ $ENV{'CURL_CA_BUNDLE'}=undef;
 sub checkdied {
     use POSIX ":sys_wait_h";
     my $pid = $_[0];
+    if(not defined $pid || $pid <= 0) {
+        return 0;
+    }
     my $rc = waitpid($pid, &WNOHANG);
-    return $rc == $pid;
+    return ($rc == $pid)?1:0;
 }
 
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