Pointer Validation
==================

If you do not suppress pointer-validation (by using the
`--no-pointer-validation' option), `makeinfo' will check the validity
of the final Info file.  Mostly, this means ensuring that nodes you
have referenced really exist.  Here is a complete list of what is
checked:

  1. If a `Next', `Previous', or `Up' node reference is a reference to a
     node in the current file and is not an external reference such as
     to `(dir)', then the referenced node must exist.

  2. In every node, if the `Previous' node is different from the `Up'
     node, then the `Previous' node must also be pointed to by a `Next'
     node.

  3. Every node except the `Top' node must have an `Up' pointer.

  4. The node referenced by an `Up' pointer must contain a reference to
     the current node in some manner other than through a `Next'
     reference.  This includes menu entries and cross references.

  5. If the `Next' reference of a node is not the same as the `Next'
     reference of the `Up' reference, then the node referenced by the
     `Next' pointer must have a `Previous' pointer that points back to
     the current node.  This rule allows the last node in a section to
     point to the first node of the next chapter.