Declare strdup only if it's not defined.

lib/canon-host.c

@@ -43,7 +43,9 @@
 # include <arpa/inet.h>
 #endif
 
+#ifndef strdup
 char *strdup ();
+#endif
 void free ();
 
 /* Returns the canonical hostname associated with HOST (allocated in a static

lib/path-concat.c

@@ -32,7 +32,9 @@
 #include <sys/types.h>
 
 char *malloc ();
+#ifndef strdup
 char *strdup ();
+#endif
 
 #ifndef DIRECTORY_SEPARATOR
 # define DIRECTORY_SEPARATOR '/'