strdup/dupstr (trunk only)

Add dupstr() as a substitute for strdup() so that out-of-memory
handling will be consistent with the rest of nethack, and make it aware
of nethack's heap logging.  It's treated like alloc() so that its caller
can be logged for NH_HEAPLOG.

     I put it into use in a few places, but there are lots more candidates
besides the existing calls to strdup() that should be replaced.

src/alloc.c

@@ -1,5 +1,4 @@
 /* NetHack 3.5	alloc.c	$Date$  $Revision$ */
-/*	SCCS Id: @(#)alloc.c	3.5	2006/07/07	*/
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -135,6 +134,28 @@ int line;
 	free(ptr);
 }
 
+/* strdup() which uses our alloc() rather than libc's malloc(),
+   with caller tracking */
+char *
+nhdupstr(string, file, line)
+const char *string;
+const char *file;
+int line;
+{
+    return strcpy((char *)nhalloc(strlen(string) + 1, file, line), string);
+}
+#undef dupstr
+
 #endif /* MONITOR_HEAP */
 
+/* strdup() which uses our alloc() rather than libc's malloc();
+   not used when MONITOR_HEAP is enabled, but included unconditionally
+   in case utility programs get built using a different setting for that */
+char *
+dupstr(string)
+const char *string;
+{
+    return strcpy((char *)alloc(strlen(string) + 1), string);
+}
+
 /*alloc.c*/