view doc/README @ 23725:6a81f88758aa

revset: delay showing parse error for the revset alias until it is referred

Before this patch, a problematic revset alias aborts execution
immediately, even if it isn't referred in the specified revset.

If old "hg" may be used too (for example, bisecting Mercurial itself),
it is also difficult to write alias definitions using features newly
introduced by newer "hg" into configuration files, because such alias
definitions cause unexpected abortion at parsing revset aliases with
old "hg".

This patch delays showing parse error for the revset alias until it is
actually referred at runtime.

This patch detects referring problematic aliases in "_expandaliases"
by examination of "revsetalias.error", which is initialized with the
error message only when parsing fails.

For usability, this patch also warns about problematic aliases, even
if they aren't referred at runtime. This should help users to know
potential problems in their alias definitions earlier.

Mercurial's documentation is kept in reStructuredText format, which is
a simple plain text format that's easy to read and edit:

  http://docutils.sourceforge.net/rst.html

It's also convertible to a variety of other formats including standard
UNIX man page format and HTML. You'll need to install Docutils:

  http://docutils.sourceforge.net/

Use the Makefile in this directory to generate the man and HTML pages.