2007-12-29  Bruno Haible  <address@hidden>

	* makeinfo/node.c (remember_node): Give a warning when the node name
	does not satisfy the documented constraints.

*** texinfo-4.11/makeinfo/node.c.bak	2007-07-08 15:11:48.000000000 +0200
--- texinfo-4.11/makeinfo/node.c	2007-12-30 02:45:33.000000000 +0100
***************
*** 280,285 ****
--- 280,319 ----
                        node, tag->line_no);
            return;
          }
+       /* The documentation says: "You cannot use periods, commas, colons or
+          parentheses within a node name."  */
+       if (strchr (node, '(') != NULL || strchr (node, ')') != NULL)
+         {
+           warning (_("Node name `%s' contains a parenthesis"), node);
+         }
+       if (strchr (node, ':') != NULL)
+         {
+           warning (_("Node name `%s' contains a colon"), node);
+         }
+       if (strchr (node, ',') != NULL)
+         {
+           warning (_("Node name `%s' contains a comma"), node);
+         }
+       /* periods are only dangerous - see info/node.c function
+          skip_node_characters - when at the start of the node name or
+          when followed by whitespace, newline, or ')'.  */
+       if (*node == '.')
+         {
+           warning (_("Node name `%s' starts with a period"), node);
+         }
+       {
+         const char *np;
+ 
+         for (np = node; *np != '\0'; np++)
+           if (*np == '.'
+               && (np[1] == ' ' || np[1] == '\t' || np[1] == '\n'
+                   || np[1] == ')'))
+             {
+               warning (_("Node name `%s' contains a period followed by whitespace or a closing parenthesis"),
+                        node);
+               break;
+             }
+       }
      }
  
    if (!(flags & TAG_FLAG_ANCHOR))