(lexer.pushback): New function. Use it for @w. Also use it, intstead

	of lexer.ignore, for @code, @uref, @footnote, @email, @asis,
	@samp, @pxref, @var, @emph, @xref, @badspell, @holl and @file.
(lexer.__read_arg): Handle nested braces properly.

doc/checkargs.py

@@ -294,7 +294,6 @@ class lexer:
     toplevel_setchapternewpage = ignore
     toplevel_set = ignore
     toplevel_macro = ignore
-    toplevel_code = ignore
     toplevel_end = ignore
     toplevel_ifinfo = ignore
     toplevel_value = ignore
@@ -320,16 +319,11 @@ class lexer:
     toplevel_html = ignore
     toplevel_ifnottex = ignore
     toplevel_top = ignore
-    toplevel_uref = ignore
     toplevel_menu = ignore
     toplevel_chapter = ignore
-    toplevel_uref = ignore
-    toplevel_footnote = ignore
-    toplevel_email = ignore
     toplevel_penalty = ignore
     toplevel_section = ignore
     toplevel_table = ignore
-    toplevel_asis = ignore
     toplevel_item = ignore
     toplevel_req = ignore
     toplevel_reqlink = ignore
@@ -340,8 +334,6 @@ class lexer:
     toplevel_multitable = ignore
     toplevel_tab = ignore
     toplevel_aux = ignore
-    toplevel_samp = ignore
-    toplevel_pxref = ignore
     toplevel_errorcode = ignore
     toplevel_misc = ignore
     toplevel_type = ignore
@@ -350,12 +342,9 @@ class lexer:
     toplevel_conftype = ignore
     toplevel_command = ignore
     toplevel_ref = ignore
-    toplevel_var = ignore
     toplevel_subsubsection = ignore
     toplevel_priv = ignore
-    toplevel_emph = ignore
     toplevel_enumerate = ignore
-    toplevel_xref = ignore
     toplevel_itemx = ignore
     toplevel_ae = ignore
     toplevel_i = ignore
@@ -377,12 +366,30 @@ class lexer:
     toplevel_anchor = ignore
     toplevel_appendix = ignore
     toplevel_display = ignore
-    toplevel_badspell = ignore
-    toplevel_holl = ignore
     toplevel_daemon = ignore
-    toplevel_file = ignore
     toplevel_TeX = ignore
 
+    def pushback(self, arg, line_no):
+        lst = list(arg)
+        lst.reverse()
+        for char in lst:
+            self.__reader.ungetc(char)
+
+    toplevel_w = pushback
+    toplevel_code = pushback
+    toplevel_uref = pushback
+    toplevel_footnote = pushback
+    toplevel_email = pushback
+    toplevel_asis = pushback
+    toplevel_samp = pushback
+    toplevel_pxref = pushback
+    toplevel_var = pushback
+    toplevel_emph = pushback
+    toplevel_xref = pushback
+    toplevel_badspell = pushback
+    toplevel_holl = pushback
+    toplevel_file = pushback
+
     def toplevel_node(self, arg, line_no):
         if self.__findex != None:
             self.__findex = None
@@ -1100,12 +1107,23 @@ class lexer:
                 
     def __read_arg(self):
         arg = ""
+        level = 0
         while 1:
             c = self.__reader.getc()
-            if c == '}':
-                return arg
-            else:
+
+            if c == '@':
+                # Handle '@{', '@}', and '@@' (and everything else
+                # that starts with `@').
                 arg = arg + c
+                c = self.__reader.getc()
+            elif c == '{':
+                level = level + 1
+            elif c == '}':
+                if level == 0:
+                    return arg
+                level = level - 1
+
+            arg = arg + c
 
     def error(self, line_no, errmsg):
         self.__reader.error(line_no, errmsg)