'''package ifneeded''' ''package version ?script?''

This command typically appears only in system configuration scripts to set up the package database. It indicates that a particular version of a particular package is available if needed, and that the package can be added to the interpreter by executing ''script''. The script is saved in a database for use by subsequent '''[package require]''' commands; typically, ''script'' sets up auto-loading for the commands in the package (or calls '''[load]''' and/or '''[source]''' directly), then invokes '''[package provide]''' to indicate that the package is present. There may be information in the database for several different versions of a single package. If the database already contains information for ''package'' and ''version'', the new ''script'' replaces the existing one. If the ''script'' argument is omitted, the current script for version ''version'' of package ''package'' is returned, or an empty string if no '''package ifneeded''' command has been invoked for this ''package'' and ''version''.

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[LV] In [Changes in Tcl/Tk 8.4.12], there is a reference to a change to commands provided via package ifneeded.
Then, in [Changes in Tcl/Tk 8.4.13], there is a reference to the [package require] command changed back to 8.4.11 behavior.
So, are these two comments related, did a change occur to package ifneeded, and what is the current state of relationship between package ifneeded, package require, commands, and mismatched version numbers?  Just trying to figure out what the state of affairds is today, in 8.5.3...

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See also:

   * [package]
   * [package provide]
   * [package require]

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