problem with `i' command

[Werner LEMBERG]

It seems there is a buglet somewhere with the `i' command.  In
groff.texinfo, there is the following in the info subfile groff-7:

======================================================================


File: groff,  Node: Operator Index,  Next: Register Index,  Prev: Escape Index, 
 Up: Top

Operator Index
**************

* Menu:

* !:                                     Expressions.
* %:                                     Expressions.
* &:                                     Expressions.
* (:                                     Expressions.
* ):                                     Expressions.
* *:                                     Expressions.
* +:                                     Expressions.
* -:                                     Expressions.
* /:                                     Expressions.
* ::                                     Expressions.
* <:                                     Expressions.
* <=:                                    Expressions.
* <?:                                    Expressions.
* =:                                     Expressions.
* ==:                                    Expressions.
* >:                                     Expressions.
* >=:                                    Expressions.
* >?:                                    Expressions.


File: groff,  Node: Register Index,  Next: Macro Index,  Prev: Operator Index,  
Up: Top

Register Index
**************

   The macro package or program a specific register belongs to is
appended in brackets.

   A register name `x' consisting of exactly one character can be
accessed as `\nx'.  A register name `xx' consisting of exactly two
characters can be accessed as `\n(xx'.  Register names `xxx' of any
length can be accessed as `\n[xxx]'.

* Menu:

* %:                                     Page Layout.
* .$:                                    Parameters.
* .a:                                    Manipulating Spacing.
* .A:                                    Built-in Registers.
* .b:                                    Artificial Fonts.
* .c:                                    Built-in Registers.
* .ce:                                   Manipulating Filling and Adjusting.

[...]

======================================================================


If I do `i .$', the command responds with

  Found ".$" in Operator Index. (`,' tries to find next.)
                ^^^^^^^^

which is clearly wrong.  On the other hand, `i .ce' gives the correct
message

  Found ".ce" in Register Index. (`,' tries to find next.)

There is one other index entry of .$ in the Concept Index:

  * number of arguments register (.$):     Parameters.

(and no other entry for .ce) in case this is of relevance.


    Werner