From ec422ec7d0f0af2bac368fe99b92d5ad7b381184 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 5 Mar 1997 10:32:41 -0300
Subject: [PATCH] skips can be nested (why not?).

---
 iolib.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/iolib.c b/iolib.c
index fb2c3b4b..bb352009 100644
--- a/iolib.c
+++ b/iolib.c
@@ -115,8 +115,14 @@ static void io_read (void)
   int c = NEED_OTHER;
   luaI_addchar(0);
   while (*p) {
-    if (*p == '{' || *p == '}') {
-      inskip = (*p == '{');
+    if (*p == '{') {
+      inskip++;
+      p++;
+    }
+    else if (*p == '}') {
+      if (inskip == 0)
+        lua_error("unbalanced `{...}' in read pattern");
+      inskip--;
       p++;
     }
     else {
@@ -125,7 +131,7 @@ static void io_read (void)
       if (c == NEED_OTHER) c = getc(lua_infile);
       m = (c == EOF) ? 0 : singlematch((char)c, p);
       if (m) {
-        if (!inskip) luaI_addchar(c);
+        if (inskip == 0) luaI_addchar(c);
         c = NEED_OTHER;
       }
       switch (*ep) {