process.c (disable_child_handler_fork_child): initialize handler for SIGPIPE

This only happens on the !POSIX_SIGNAL case; but one may
test with the following:

    --- a/process.c
    +++ b/process.c
    @@ -3479,6 +3479,7 @@ disable_child_handler_fork_parent(struct child_handler_disabler_state *old)
     #endif
     }

    +#undef POSIX_SIGNAL
     /* This function should be async-signal-safe.  Actually it is. */
     static int
     disable_child_handler_fork_child(struct child_handler_disabler_state *old, char *errmsg, size_t errmsg_buflen)

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@54890 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Tue May  3 05:35:54 2016  Eric Wong  <e@80x24.org>
+
+	* process.c (disable_child_handler_fork_child):
+	  initialize handler for SIGPIPE for !POSIX_SIGNAL
+
 Mon May  2 23:03:42 2016  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* win32/win32.c, include/ruby/win32.h (rb_w32_utruncate): implements new

process.c

@@ -3502,8 +3502,12 @@ disable_child_handler_fork_child(struct child_handler_disabler_state *old, char
     for (sig = 1; sig < NSIG; sig++) {
         int reset = 0;
 #ifdef SIGPIPE
-        if (sig == SIGPIPE)
+        if (sig == SIGPIPE) {
             reset = 1;
+#ifndef POSIX_SIGNAL
+            handler = SIG_DFL;
+#endif
+	}
 #endif
         if (!reset) {
 #ifdef POSIX_SIGNAL