* sigproc.cc (wait_sig): Make sure that strace is activated on __SIGSTRACE by

calling new strace::activate function.
* strace.cc (strace::activate): Rename from strace::strace.
* strace.h (strace::activate): Define new function.
(strace::strace): Call activate.

winsup/cygwin/include/sys/strace.h

@@ -39,7 +39,8 @@ class strace
   void write (unsigned category, const char *buf, int count);
   unsigned char _active;
 public:
-  strace ();
+  void activate ();
+  strace () {activate ();}
   int microseconds ();
   int version;
   int lmicrosec;