Add stpcpy to autoconf machinery

* configure.ac: Add stpcpy to AC_CHECK_FUNCS.
* defs.h: Frame stpcpy with "if !defined HAVE_STPCPY".
* util.c: Likewise.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

configure.ac

@@ -235,6 +235,7 @@ AC_CHECK_FUNCS([ \
 	strsignal \
 	sys_siglist \
 	_sys_siglist \
+	stpcpy \
 ])
 AC_CHECK_HEADERS([ \
 	inttypes.h \

defs.h

@@ -681,12 +681,14 @@ extern void tv_sub(struct timeval *, struct timeval *, struct timeval *);
 extern void tv_mul(struct timeval *, struct timeval *, int);
 extern void tv_div(struct timeval *, struct timeval *, int);
 
+#if !defined HAVE_STPCPY
 /* Some libc have stpcpy, some don't. Sigh...
  * Roll our private implementation...
  */
 #undef stpcpy
 #define stpcpy strace_stpcpy
 extern char *stpcpy(char *dst, const char *src);
+#endif
 
 #ifdef SUNOS4
 extern int fixvfork(struct tcb *);

util.c

@@ -164,6 +164,7 @@ xlookup(const struct xlat *xlat, int val)
 	return NULL;
 }
 
+#if !defined HAVE_STPCPY
 char *
 stpcpy(char *dst, const char *src)
 {
@@ -171,6 +172,7 @@ stpcpy(char *dst, const char *src)
 		dst++;
 	return dst;
 }
+#endif
 
 /*
  * Generic ptrace wrapper which tracks ESRCH errors