fix from lark: make memarea_strndup() work even at the end of a mmap chunk. Bug was harmless for now, I think.

svn:r19094

ChangeLog

@@ -12,6 +12,10 @@ Changes in version 0.2.1.14-??? - 2009-03-??
       0.2.0.33.
     - Avoid double-free on list of successfully uploaded hidden
       service discriptors.  Fix for bug 948.  Bugfix on 0.2.1.6-alpha.
+    - Change memarea_strndup() implementation to work even when
+      duplicating a string at the end of a page.  This bug was
+      harmless for now, but could have meant crashes later. Fix by
+      lark.  Bugfix on 0.2.1.1-alpha.
 
   o Minor features (controller):
     - Try harder to look up nicknames for routers on a circuit when

src/common/memarea.c

@@ -237,7 +237,7 @@ memarea_strndup(memarea_t *area, const char *s, size_t n)
   size_t ln;
   char *result;
   const char *cp, *end = s+n;
-  for (cp = s; *cp && cp < end; ++cp)
+  for (cp = s; cp < end && *cp; ++cp)
     ;
   /* cp now points to s+n, or to the 0 in the string. */
   ln = cp-s;