diff mercurial/dispatch.py @ 10364:de1e7099d100

dispatch: provide help for disabled extensions and commands

Before a command is declared unknown, each extension in hgext is searched,
starting with hgext.<cmdname>. If there's a matching command, a help message
suggests the appropriate extension and how to enable it.

Every extension could potentially be imported, but for cases like rebase,
relink, etc. only one extension is imported.

For the case of "hg help disabledext", if the extension is in hgext, the
extension description is read and a similar help suggestion is printed.
No extension import occurs.

--- a/mercurial/dispatch.py	Sun Feb 07 11:32:08 2010 +0100
+++ b/mercurial/dispatch.py	Sun Feb 07 14:01:43 2010 +0100
@@ -93,7 +93,12 @@
         ui.warn(_("killed!\n"))
     except error.UnknownCommand, inst:
         ui.warn(_("hg: unknown command '%s'\n") % inst.args[0])
-        commands.help_(ui, 'shortlist')
+        try:
+            # check if the command is in a disabled extension
+            # (but don't check for extensions themselves)
+            commands.help_(ui, inst.args[0], unknowncmd=True)
+        except error.UnknownCommand:
+            commands.help_(ui, 'shortlist')
     except util.Abort, inst:
         ui.warn(_("abort: %s\n") % inst)
     except ImportError, inst:
@@ -218,6 +223,11 @@
             def fn(ui, *args):
                 ui.warn(_("alias '%s' resolves to unknown command '%s'\n") \
                             % (self.name, cmd))
+                try:
+                    # check if the command is in a disabled extension
+                    commands.help_(ui, cmd, unknowncmd=True)
+                except error.UnknownCommand:
+                    pass
                 return 1
             self.fn = fn
             self.badalias = True