small improvement

lzio.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lzio.c,v 1.29 2004/04/30 20:13:38 roberto Exp roberto $
+** $Id: lzio.c,v 1.30 2005/05/17 19:49:15 roberto Exp roberto $
 ** a generic input stream interface
 ** See Copyright Notice in lua.h
 */
@@ -34,10 +34,12 @@ int luaZ_fill (ZIO *z) {
 
 int luaZ_lookahead (ZIO *z) {
   if (z->n == 0) {
-    int c = luaZ_fill(z);
-    if (c == EOZ) return c;
-    z->n++;
-    z->p--;
+    if (luaZ_fill(z) == EOZ)
+      return EOZ;
+    else {
+      z->n++;  /* luaZ_fill removed first byte; put back it */
+      z->p--;
+    }
   }
   return char2int(*z->p);
 }
@@ -56,14 +58,8 @@ void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) {
 size_t luaZ_read (ZIO *z, void *b, size_t n) {
   while (n) {
     size_t m;
-    if (z->n == 0) {
-      if (luaZ_fill(z) == EOZ)
-        return n;  /* return number of missing bytes */
-      else {
-        ++z->n;  /* filbuf removed first byte; put back it */
-        --z->p;
-      }
-    }
+    if (luaZ_lookahead(z) == EOZ)
+      return n;  /* return number of missing bytes */
     m = (n <= z->n) ? n : z->n;  /* min. between n and z->n */
     memcpy(b, z->p, m);
     z->n -= m;