some little bugfixes

lib/pure/os.nim

@@ -699,7 +699,10 @@ when defined(windows):
       discard FreeEnvironmentStringsA(env)
 
 else:
-  when defined(macosx):
+  const
+    useNSGetEnviron = defined(macosx) and 
+      (defined(createNimRtl) or defined(useNimRtl))
+  when useNSGetEnviron:
     # From the manual:
     # Shared libraries and bundles don't have direct access to environ, 
     # which is only available to the loader ld(1) when a complete program
@@ -716,7 +719,7 @@ else:
   proc getEnvVarsC() =
     # retrieves the variables of char** env of C's main proc
     if not envComputed:
-      when defined(macosx):
+      when useNSGetEnviron:
         var gEnv = NSGetEnviron()^
       var i = 0
       while True:

lib/pure/pegs.nim

@@ -751,7 +751,7 @@ proc match*(s: string, pattern: TPeg, matches: var openarray[string],
   ## returned.
   var c: TCaptures
   c.origStart = start
-  result = rawMatch(s, pattern, start, c) == len(s) -start
+  result = rawMatch(s, pattern, start, c) == len(s) - start
   if result:
     for i in 0..c.ml-1:
       matches[i] = copy(s, c.matches[i][0], c.matches[i][1])