made getenv() more threadsafe for win32

lib/netrc.c

@@ -95,9 +95,14 @@ int ParseNetrc(char *host,
 
 #define NETRC DOT_CHAR "netrc"
 
-  if(!home || (strlen(home)>(sizeof(netrcbuffer)-strlen(NETRC))))
+  if(!home)
     return -1;
 
+  if(strlen(home)>(sizeof(netrcbuffer)-strlen(NETRC))) {
+    free(home);
+    return -1;
+  }
+
   sprintf(netrcbuffer, "%s%s%s", home, DIR_CHAR, NETRC);
 
   file = fopen(netrcbuffer, "r");
@@ -162,6 +167,8 @@ int ParseNetrc(char *host,
     fclose(file);
   }
 
+  free(home);
+
   return retcode;
 }