[Boost-build] [PATCH] NORMALIZE_PATH patch.

From: Jurko Gospodnetiæ (jurko.gospodnetic_at_[hidden])
Date: 2008-05-03 23:46:06

   Hi all.

   Attached is a patch for the NORMALIZE_PATH builtin rule as well as an 
appropriate update for the path.jam module where that rule was being 
used to implement path.join and related operations.

   As it was written before the rule had some 'random' behavior in some 
borderline cases such as: passing it a folder whose path starts with a 
backslash (not a slash) or passing it an empty initial path element or 
some other combinations with empty path elements. In those cases it 
would sometimes 'incorrectly' root or un-root the path (add or remove 
the leading slash).

   Also, now it works correctly with multiple successive path separator 
characters in any position (beginning, middle or end) which makes native 
path processing more general.

   Due to this rule having some 'messy' behavior the path.join rule and 
its user make-NT rule had some twisted logic in them to work around all 
the problems this causes. This patch invalidates this logic and it has 
been replaced now with much simpler one (detailed comments added).

   Other NORMALIZE_PATH callers should not be affected since both the 
old and the new version work the same on 'regular' paths (i.e. those not 
mentioned above).

   The new functionality for recognizing Boost Jam versions has been 
used to make Boost Build scripts use the old path functionality when 
using Boost Jam older than 3.1.17 and use the new functionlity otherwise.

   As consequence, if and when this patch is applied everyone using the 
trunk version of Boost Build and an older 3.1.17 version of Boost.Jam 
will need to recompile their Boost Jam executable.

   The patch does not affect any Boost Build test results.

   Could someone please review this and let me know if it is ok to 
commit it?

   Best regards,
     Jurko Gospodnetiæ